U.S. Department of Commerce

Seattle, Washington

NOAA Technical Report NMFS 146

A Technical Report of the Fishery Bulletin

FAO Fisheries Synopsis 157

Synopsis of Biological Data on the

Nassau Grouper, Epinephelus striatus

(Bloch, 1792), and the Jewfish,

E. itajara (Lichtenstein, 1822)

Yvonne Sadovy

Anne-Marie Eklund

July 1999
iii

Contents

Introduction 1

1 IDENTITY 2

1.1 Nomenclature 2

1.11 Valid name 2

1.12 Synonymy 4

1.2 Taxonomy 4

1.21 Affinities 4

1.22 Taxonomic status 5

1.23 Subspecies 5

1.24 Standard common names, vernacular names 5

1.3 Morphology 5

1.31 External morphology 5

*1.32 Cytomorphology

1.33 Protein specificity 5

2 DISTRIBUTION 6

2.1 Total area 6

2.2 Differential distribution 7

2.21 Spawn, larvae, and juveniles 7

2.22 Adults 12

2.3 Determinants of distribution changes 12

*2.4 Hybridization

3 ECONOMIC AND LIFE-HISTORY 13

3.1 Reproduction 13

3.11 Sexuality 13

3.12 Maturity 14

3.13 Mating 15

3.14 Fertilization 16

3.15 Gonads 16

3.16 Aggregation and spawning 17

3.17 Spawn 20

3.2 Preadult phase 20

3.21 Embryonic phase 20

3.22 Larval and juvenile phases 20

3.3 Adult phase 23

3.31 Longevity 23

3.32 Hardiness 25

3.33 Competitors 25

3.34 Predators 26

3.35 Parasites, diseases, and abnormalities 26

*3.36 Chemical composition

3.4 Nutrition and growth 26

3.41 Feeding and food (includes 3.42) 26

3.43 Growth rate 28

*3.44 Metabolism

3.5 Behavior 30

3.51 Migrations and local movements 30

*3.52 Schooling

3.53 Responses to stimuli 32
4 POPULATION 33

4.1 Structure 33

4.11 Sex ratio 33

4.12 Age composition 33

4.13 Size composition 35

*4.14 Subpopulations

4.2 Abundance and density 36

4.3 Natality and recruitment 40

4.31 Reproduction rates 40

4.32 Factors affecting reproduction 42

4.33 Recruitment 42

4.4 Mortality and morbidity 42

4.41 Mortality rates 42

4.42 Factors affecting mortality 43

4.5 Dynamics of population 43

4.6 The population in the community and the ecosystem 43

5 EXPLOITATION 44

5.1 Fishing equipment 44

5.2 Fishing areas 46

5.21 General geographic distribution and range (includes 5.22) 46

5.23 Depth ranges 48

5.3 Fishing seasons 49

5.4 Fishing operations and results 51

5.41 Fishing effort and intensity 51

5.42 Selectivity 52

5.43 Catches 53

6 PROTECTION AND MANAGEMENT 56

6.1 Regulatory measures 56

6.2 Environmental changes 58

6.3 Regulatory strategies 58

7 AQUACULTURE 58

Acknowledgments 59

Literature Cited 59

* No information available

iv
1

Introduction

The Nassau grouper, Epinephelus striatus, and the jewfish, E. itajara, are two important and conspicuous members of reef communities throughout the western Atlantic and Caribbean. These species are found from inshore to about 100 m in reef, mangrove, seagrass, and

estuarine habitats. They are large, long-lived predators

exceeding 800 mm (the Nassau) and 2,000 mm (the jewfish) in length and living three or four decades. They

prey on a wide diversity of fishes and invertebrates. The

sexual pattern of the Nassau grouper is primarily

gonochoristic (separate sexes) thereby differing from

the protogynous hermaphroditism (female to male sex

change) more typical of groupers. The sexual pattern

of the jewfish has not been confirmed.

Both species, but particularly the Nassau grouper, are

of significant commercial and recreational interest,

taken primarily by handline, fish trap, and speargun. In

many insular areas, the Nassau grouper was once among

the most abundant fishery species. However, since the

1970s, landings, mean sizes, and catch per unit of effort

Synopsis of Biological Data on the Nassau Grouper,

Epinephelus striatus (Bloch, 1792), and

the Jewfish, E. itajara (Lichtenstein, 1822)

YVONNE SADOVY

Department of Ecology and Biodiversity

The University of Hong Kong

Pokfulam Road

Hong Kong, China

ANNE-MARIE EKLUND

Divsion of Protected Resources and Biodiversity

Southeast Fisheries Science Center

National Marine Fisheries Service

75 Virginia Beach Drive

Miami, Florida 33149

ABSTRACT

Information on the biology, fishery resources, exploitation patterns, management, and

conservation status of two species of grouper—the Nassau grouper, Epinephelus striatus, and

the jewfish, Epinephelus itajara—is compiled, reviewed, and analyzed.

have all fallen sharply for both groupers in regional fisheries, and growth and recruitment overfishing are suspected or severe in some places. Spawning stock biomass per recruit has been estimated at close to 1%, far

below the recommended minimum of 30%. Because of

their large average sizes and ages at sexual maturity—

400–450 mm TL, 4+ years, Nassau grouper, and 1100–

1200 mm TL, 5+ years, jewfish—relative to other fishes

in the multi-species fisheries targeted in the region, both

species are often taken as juveniles. Nassau grouper, for

example, recruit into the fishery well before attaining

sexual maturity; capture age averages 2–9 years, which

is young for a species that can attain 29 years or more.

Large individuals of both species are particularly sought

by recreational spearfishers, and reproductively active

adults are often taken from spawning aggregations. The

jewfish is now rare where formerly it was abundant and

both species are commercially extinct for fishery purposes throughout significant portions of their ranges.

The fact that such long-lived, slow-growing fishes are

extremely susceptible to fishing has long been recognized, and species that aggregate at specific times and
2 NOAA Technical Report 146

locations to spawn are particularly vulnerable (e.g.

Polovina and Ralston, 1987; Bohnsack1). The Nassau

grouper and jewfish assemble to spawn at specific times

and locations in aggregations numbering as many as tens

of thousands of individuals in the Nassau grouper and

tens to one hundred, or more, individuals in the jewfish. The aggregations last only a few weeks each year

and represent most, if not all, of the total annual reproductive effort for both species. Between 60 and 80 Nassau

grouper aggregations have been identified, many exploited since at least the turn of the century. All, with

the notable exception of Bermuda, are within the latitudinal range of 15–26° N. Heavy fishing has had such a

severe impact on many of these aggregations that about

one-third of them no longer form at traditional sites.

Of particular note are the almost complete loss of aggregations from Cuba and the Greater Antilles, and

declines in aggregations in the Bahamas. Similarly, of

the few jewfish aggregations identified, one quarter no

longer form. The evidently specific nature of the spawning sites means that adults may be habitat-limited to some

extent, dependent for reproduction on aggregation sites

which could represent critical bottlenecks in the life

histories of these species.

There may also be specific times and places for very

early life history phases of these two groupers. The time

period over which settlement occurs in Nassaus, when

larvae leave the plankton and colonize the substrate, appears to be brief, lasting but days each year. Such a short

annual larval settlement period may increase vulnerability to short-term adverse weather conditions, to poor recruitment years, or when adult population levels are low.

For early post-settlement fish, nursery areas may be quite

specific. After settlement, the apparent importance of

macroalgae and seagrass beds to juvenile Nassau grouper, and of mangroves to jewfish, may limit suitable nursery habitat for young fish of these species. Indeed, in

reef fishes in general, suitable settlement habitat appears

to be an important factor in enabling young, vulnerable

fishes to avoid predation.

The conservation status of the Nassau grouper and

the jewfish is precarious in some areas. Standard fishery

management approaches such as quotas and size limits

are not effective for larger reef species in multi-species

fisheries. The greatest protection for such species is likely

afforded by restrictions or elimination of gear and effort, especially over spawning aggregations, to protect

spawning biomass. Marine reserves can protect both juvenile and adult biomass and, if properly placed, the

critical habitats on which they may depend. Indeed,

some recoveries in both species may already have occurred from protection. Nonetheless, both species are

1 Bohnsack, J. A. 1989. Protection of grouper spawning aggregations.

Coastal Resources Division Contr. No. 88-89-06, 8 p.

in urgent need of management throughout much of

their geographic ranges. In 1996, both species were included on the “Red List” of the International Union for

the Conservation of Nature and both are candidates for

the United States Endangered Species List. Moratoriums are now in effect for the Nassau grouper and jewfish in all waters of the United States and Bermuda. Aquaculture and stock enhancement initiatives are promising

but are not solutions to overfishing nor are they excuses

not to manage.

1 IDENTITY

1.1 Nomenclature

1.11 Valid name

Epinephelus striatus (Bloch, 1792) (Fig. 1) Nassau grouper, Epinephelus striatus (Bloch, 1792). Original description as Anthias striatus Bloch, 1792:6:125, pl. 324 (type

locality; Atlantic Ocean) (Smith, 1971; Heemstra and

Randall, 1993). The name comes from the Greek

Epinephelus, meaning clouded over, in reference to the

membrane believed to cover the eye of Epinephelus ruber

(Mycteroperca rubra) (Smith, 1971) and the Latin, striatus,

provided with stripes, in reference to the color pattern.

Epinephelus itajara (Lichtenstein, 1822) (Fig. 2) Jewfish

(formerly giant grouper), Epinephelus (Promicrops) itajara

(Lichtenstein, 1822). Original description as Serranus

itajara Lichtenstein, 1822:278 (type locality: Brazil)

(Smith, 1971; Heemstra and Randall, 1993). The derivation of itajara is unclear.

1.12 Synonymy

The following primary synonymies are based on

Heemstra and Randall (1993) and Heemstra2. For full

synonymy see Smith (1971); see also Bullock and Smith

(1991) for E. itajara.

Epinephelus striatus

Anthias cherna Bloch and Schneider, 1801

Serranus gymnopareius Valenciennes in Cuvier and

Valenciennes, 1828

Epinephelus itajara

? Serranus mentzelii Valenciennes in Cuvier and Valenciennes 1828

2 Heemstra, Phillip. 1993. J.L.B. Smith Institute of Ichthyology, Private Bag 101 Grahamstown, 6140 South Africa. Personal commun.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 3

Figure 1

Nassau grouper, Epinephelus striatus, adult, showing external morphology; upper shows normal coloration while lower

shows the bicolor form seen at spawning aggregations and during some intraspecific interactions (redrafted from Heemstra

and Randall, 1993).

Figure 2

Jewfish, Epinephelus itajara, adult, showing external morphology (redrafted from Heemstra and Randall, 1993).
4 NOAA Technical Report 146

? Serranus galeus Müller and Troschel, 1848

Serranus guasa Poey, 1861

Serranus quinquefasciatus Bocourt, 1868

? Promicrops esonue Ehrenbaum, 1914

? Promicrops ditobo Roux and Collignon, 1954

1.2 Taxonomy

1.21 Affinities

Suprageneric

Phylum Chordata

Class Osteichthyes

Superorder Acanthopterygii

Order Perciformes

Suborder Percoidei

Family Serranidae

Subfamily Epinephelinae

Systematics and distribution of the groupers have been

reviewed by Smith (1971), Johnson (1983), Baldwin and

Johnson (1993), and Heemstra and Randall (1993). Systematics based on larval serranids were carried out by

Kendall (1979) and by Baldwin and Johnson (1993).

Larval features provide the only evidence of a monophyletic Epinephelini (Baldwin and Johnson, 1993).

Generic For a comprehensive synonymy see Heemstra

and Randall (1993) from which the following description was taken.

Genus Epinephelus Bloch, 1793. Epinephelus is the most

speciose genus of the subfamily Epinephelinae which

comprises a number of large to very large sea basses that

are the most common top level predators on coral reefs.

Body elongate, robust (subcylindrical), oblong or deep

and compressed; body depth greater than, subequal to,

or less than, head length and contained 2.3 to 3.7 times

in standard length (SL), the body width 1.8 to 2.8 in the

depth. Head length 2.1 to 2.8 times in SL; preorbital

depth 6.7 to 15 times in head length; preopercle

rounded or angular, the posterior edge serrate, with the

serrae at the angle more or less enlarged; a few species

with small serrae (mostly covered by skin) on the ventral edge; canines present at front of jaws, but they may

be small in some species; no distinctly enlarged canine

teeth at midside of lower jaw; teeth present on palatines;

maxilla of adults without a distinct bony knob on

ventroposterior corner, but there may be an abrupt step

or hook-like process (covered by the upper lip) on the

distal part of the ventral edge; supramaxilla well developed. Dorsal fin usually with XI spines and 12 to 19 rays,

the fin origin above the opercle; length of base of softrayed part of dorsal fin not more than base of spinous

part; anal fin with III distinct spines and 7 to 10 rays;

pectoral fin rounded, the middle rays longest; caudal

branched rays and 7 to 10 procurrent rays in lower part.

Scales on body ctenoid or smooth. Supraneural bones

2; dorsal and anal fins without trisegmental pterygiophores; rear edge of first dorsal pterygiophore with

or without excavation for tip of second neural spine;

epipleural ribs on vertebrae 1 to 10. The diversity of cranial morphology of the many species assigned to

Epinephelus makes it difficult to recognize diagnostic cranial characters for the genus. Characters of the larvae

(Leis, 1986): pelvic-fin spines with 4 ridges; supraocular

ridge with a single strong spine; spines on lower limb of

preopercle serrate; posterior 1 or 2 dorsal-fin spines

develop first as soft rays and all spines are present in

larvae of 13.5 to 16 mm; all anal-fin spines are present

prior to settlement at a length of 16 to 18 mm SL.

Specific The following diagnoses are from Smith

(1971) and Heemstra and Randall (1993):

Epinephelus striatus Gill rakers 8 or 9 on upper limb

and 15 to 17 on lower limb, total 23 to 26. Dorsal fin XI,

16–18 rays, the third or fourth spine longest and the

interspinous membranes distinctly notched; anal fin, III,

8; pectoral-fin rays 17–19; caudal fin rounded in juveniles, convex in adults. Scales ctenoid, about 50 lateralline scales and 98 to 108 lateral-scale series. Skull crests

well developed, convergent anteriorly. Supraethmoid

forming floor of pit between anterior ends of frontals.

There are 21–25 pyloric caeca. Proportional measurements of 10 specimens are given in Table 7 in Smith

(1971).

Epinephelus itajara Gill rakers 8 or 9 on upper limb

and 13 to 15 on lower limb, total 21 to 24; gill arches

covered with small bony plates. Dorsal fin XI spines and

15–16 rays, the spines short, 3rd to 11th subequal and

shorter than the first ray, the membranes distinctly indented between the spines; anal fin with III spines and

8 rays; pectoral-fin rays 18 or 19; caudal fin rounded.

Body scales strongly ctenoid; lateral-line scales 61 to 64,

each with 4 to 6 radiating ridges; lateral-scale series 89–

112. Skull crests low with frontoparietal crests converging anteriorly. Supraethmoid expanded transversely to

form wall anterior to frontals. Proportional measurements of 10 specimens are given in Table 20 in Smith

(1971). E. itajara is one of only two Epinephelus species

found in both eastern Pacific and western Atlantic

Oceans.

1.22 Taxonomic status

The distinctive color pattern of the Nassau grouper has

spared it from the nomenclatural confusion of less easily recognizable species (Smith, 1971). Smith (1971)

demoted the genus Promicrops, containing E. itajara and
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 5

E. lanceolatus, to a subgenus of Epinephelus, stating that

the two species in Promicrops, although highly specialized and distinctive, were clearly allied with other species of Epinephelus. Heemstra and Randall (1993) concur with this opinion.

1.23 Subspecies

No subspecies are recognized.

1.24 Standard common names, vernacular names

The word “grouper” comes from the Portuguese

“garrupa” probably derived from a similar sounding

name that South American natives used for large groupers. The Nassau grouper is variously known as: Hamlet

(Bermuda); Merou rayé (French); Cherna criolla

(Cuba); Mero cherna (Puerto Rico); Mero gallina, mero

batata (Venezuela) (Erdman, 1987; Butler et al., 1993;

Heemstra and Randall, 1993; Cervigón, 1994). The jewfish is variously known as Merou géant (French); Mero

guasa (Colombia); Mero (Brazil); Cherna (Mexico);

Cherne (Peru); Mero sapo (Puerto Rico); June fish (Colombia); Guasa (Venezuela) (Thompson, 1945; Erdman,

1987; Heemstra and Randall, 1993).

1.3 Morphology

1.31 External morphology

The following descriptions are based predominantly on

Smith (1971) and Heemstra and Randall (1993).

Epinephelus striatus The Nassau grouper is a moderatesized Epinephelus with large eyes and a robust body (Fig.

1). Body depth distinctly less than head length, depth

contained 2.6 to 2.9 times in SL (for fish 160 to 330 mm

SL). Head length contained 2.4 to 2.6 times in SL; interorbital convex; preopercle evenly serrate, without

salient angle; posterior nostrils somewhat enlarged and

elongated or comma-shaped in large adults. Ground

color generally buff, with 5 dark brown vertical bars and

a large black saddle blotch on top of caudal peduncle; a

row of black spots below and behind eye. Distinctive dark

tuning-fork mark beginning at front of upper jaw, extending dorsally along interorbital region, and bifurcating on top of head behind the eyes; another dark band

from tip of snout through eye and then curving upward

to meet its fellow just before dorsal-fin origin. Some fish

have irregular pale spots and blotches all over the head

and body; specimens from deep water are somewhat

pinkish or reddish ventrally. The inside of the mouth is

red, the teeth are caniniform and villiform and are in

two series in each jaw (Smith, 1978). The range of color

is wide (Section 3.16). Color pattern can change within

minutes from almost white to bicolored to uniformly

dark brown, according to the behavioral state of the fish

(Longley, 1917; Colin, 1992; Heemstra and Randall, 1993;

Carter et al., 1994). A distinctive bicolored pattern (Fig. 1)

is seen when two adults or an adult and large juvenile meet

and is frequently observed in spawning aggregations (Section 3.16) (Heemstra and Randall, 1993). Only dots around

the eyes and the blotch on the caudal peduncle do not

change (Smith, 1971). Juveniles exhibit a color pattern similar to adults (e.g. Silva Lee, 1977).

Epinephelus itajara The jewfish is the largest of the

western North Atlantic groupers, readily distinguishable

from all other species by its nearly terete shape, short

dorsal spines, short canine teeth and distinctive coloration; head extremely broad and flat, eyes relatively small

(Fig. 2). Body elongate, the greatest width more than

half of body depth, which is distinctly less than head

length (in fish 150 to 1600 mm); body depth contained

2.7 to 3.4 times in SL. Head length contained 2.3 to 2.9

times in SL; head extremely broad; interorbital flat, the

width equals eye diameter in fish 100 to 150 mm SL;

distinctly greater than eye diameter in fish 180 to 250

mm SL, and 1.5 to 3.4 times greater than eye diameter

in fish 300 to 1600 mm SL; eye diameter contained 5 to

8 times in head length for fish 100 to 300 mm SL and 8

to 13 times in head length for fish 350 to 1600 mm SL;

preopercle rounded, finely serrate; nostrils round,

subequal; maxilla scaly, reaching well past eye; midlateral

part of lower jaw with 3 to 5 rows of subequal teeth; no

canines at front of jaws. Scales ctenoid and rugose in

adults. Body color is brownish yellow, or may be grey or

greenish. The head and the dorsal part of the body and

fins have small black spots, which get smaller with

growth. Fish as small as 87 mm SL are greenish or tawny,

have 3 or 4 faint, irregular, subvertical dark bars posteriorly on body and another covering rear half of caudal

peduncle. They have longer dorsal spines and more vivid

coloration but otherwise do not markedly differ from

adults (Bullock and Smith, 1991). There is no saddlelike blotch on the caudal peduncle (Rivas, 1964).

1.33 Protein specificity

Limited work on genetic variability in the Nassau grouper suggests that, while gene flow occurs throughout

much of its geographic range, the relative contributions

of local and foreign recruitment to particular populations have yet to be determined. Cellular DNA in the

Nassau was reported to be 1.3 picograms (haploid), similar to that of other serranids and similar to the average

value of a wide diversity of other percomorph fishes

(Hinegardner and Rosen, 1972).

Hateley (in press) presented preliminary results on

genetic variability in the Nassau grouper, based on en-
6 NOAA Technical Report 146

zyme electrophoresis. Clearly resolved enzyme phenotypes were obtained at 20 loci, of which 5 exhibited polymorphisms. On the basis of a sample of 264 individuals

taken from Belize, Bahamas, Turks and Caicos and Cayman Islands, intermediate to low levels of genetic variability were indicated; mean heterozygosity per locus was

0.024; proportion of polymorphic loci = 0.15, and the

mean effective number of alleles was 1.45. There was no

evidence for population sub-structuring by sex or smallscale spatial distribution, nor for macrogeographic stock

separation. The results were interpreted as being consistent with a single panmictic population within the northern Caribbean basin and suggested high gene flow in the

region. However, since gel electrophoresis can detect only

differences among samples and not similarities, it may not

detect real inter-stock differences and more sensitive methods must be applied to increase resolution (Hateley3).

A study of genetic population structure in the jewfish

and Nassau grouper, using PCR (Polymerase Chain Reaction)-amplified mtDNA genes and nuclear microsatellites, revealed no clearly defined population substructuring for either species at the geographic locations

sampled, i.e. Belize, Cuba, Bahamas, Florida for Nassau,

and Belize and Florida for jewfish (Sedberry et al.4).

Although these data indicate that spawning aggregations

are not exclusively self-recruiting and that the larval

stages can disperse over great distances, this study does

not allow a definitive evaluation of the relative importance of self-recruitment and larval immigration to local populations (Sedberry et al.4). Since the use of

microsatellites is not confounded by environmental variables, their use represents a superior approach for examining stock structure compared to non-genetic approaches,

such as otolith microchemistry (Patterson et al.5).

2 DISTRIBUTION

2.1 Total area

Epinephelus striatus The Nassau grouper is distributed

in waters off Bermuda and Florida throughout the Bahamas and Caribbean Sea, down to southern Brazil (Smith,

1971; Acero and Garzon-Ferreira, 1991; Heemstra and

3 Hateley, Jon. 1994. Division of Fisheries, Department of Agriculture, Fisheries and Parks, P.O. Box CR 52, Crawl CR BX, Bermuda.

Personal commun.

4 Sedberry, G. R., D. E. Stevenson, and R. W. Chapman. 1996. Stock

identification in potentially threatened species of grouper

(Teleostei: Serranidae: Epinephelinae) in Atlantic and Caribbean

Waters. Final Rep. MARFIN Grant No. NA47FF0012. South Carolina Dept. of Natural Resources, Marine Resources Research Institute. p. 51.

5 Patterson, H. M., S. R. Thorrold, and J. M. Shenker. Analysis of otolith

chemistry in Nassau grouper (Epinephelus striatus) from the Bahamas

and Belize using solution-based ICPMS. Unpubl. manuscr., 24 p.

Randall, 1993; Cervigón, 1994) (Fig. 3). To the west, it

occurs off the Yucatan Peninsula, Mexico, at Arrecife

Alacranes (north of Progreso) (Hildebrand et al., 1964).

It is a rare or transient species in the Gulf of Mexico

(Reed, 1941; Hoese and Moore, 1977) where it is replaced by Epinephelus morio (Smith, 1971).

The Nassau grouper is primarily a shallow water, insular species and, when mature, is most abundant in

clear water with high relief coral reefs or rocky substrate;

it occurs from the shoreline to at least 100 m and on

both natural and artificial reefs (Smith, 1971; Beets and

Hixon, 1994; Colin et al., 1997). Although it is fished to

130 m, greatest trap catches in the Leeward Islands were

from 52–60 m (Brownell and Rainey, 1971). In Venezuela it is common to 40 m in the Archipelago Los Roques,

but rare in northeastern islands (Cervigón, 1966).

Nassau grouper otoliths have been retrieved from a

variety of sites (middens) in prehistoric fishing communities of the Caribbean, and the species represented an

important component of these communities. Otoliths

were relatively abundant at sites on eastern Antigua (AD

500–1150), in Grenada (AD 0–500, AD 1000–1500), San

Salvador, Bahamas (AD 850–1100) St. John, Virgin Islands (AD 700–1200), Florida west coast (2000–1000 BC,

AD 150–300, AD 400–1000), St. Lucia, West Indies (AD

0–1500) and on the north coast of Jamaica (no date)

(Wing et al., 1968; Wing and Reitz, 1982).

Epinephelus itajara The jewfish occurs in tropical and

subtropical waters of the Atlantic Ocean (Fig. 4), from

Florida to Brazil down to São Paulo State, throughout

the Gulf of Mexico, and in the Caribbean. It is also recorded from Bermuda (as Promicrops itajara) (Smith,

1959, 1961; Ferreira Padovani and Maida, 1995), although it is rare there, and is present in the eastern Pacific from the Gulf of California to Peru (Smith, 1971;

Heemstra and Randall, 1993). It is common on the

Campeche Bank off southern Mexico (Stewart, 1987)

and is known from the isolated Isla de Aves (Brownell

and Gúzman, 1974). It is also reported from the eastern

Atlantic from Sénégal to the Congo but is rare in the

Canary Islands (Heemstra and Randall, 1993). Heemstra

and Randall doubt that jewfish of the eastern and western Atlantic and the eastern Pacific share a common

gene pool, but could find no evidence, either in specimens examined or in the published literature, to confirm that different species are involved. Heemstra

(1991), however, suggests that juveniles, with their predilection for estuarine and mangrove habitats, could

easily traverse the Isthmus of Panama via the Panama

Canal. This species was once common in Florida and in

parts of the Gulf of Mexico but infrequently encountered in the West Indies (Randall, 1983).

Jewfish, in general, prefer holes, caves, or places where

they can find shelter (Nagelkerken, 1981). Along the
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 7

Figure 3

Geographic distribution (indicated by the solid line) of the Nassau grouper, Epinephelus

striatus, in the western Atlantic (redrafted from Heemstra and Randall, 1993).

Florida west coast, this species ranges from shallow bays

and estuaries to offshore, invading tidal streams on feeding forays (Odum et al.6). Large adults are found around

high-relief ledges and offshore wrecks (Smith, 1976) and

in shallow water in the Everglades, Florida Bay, and the

Florida Keys (Bullock and Smith, 1991). The center of

abundance of jewfish along the west coast of Florida

appears to be in the vicinity of the Ten Thousand Islands (south of Naples), where extensive mangrove

swamp habitat, suitable for juveniles, exists (Bullock and

Smith, 1991). Jewfish otoliths were found from prehistoric fishing communities in Florida, but at no other

sites surveyed in the Caribbean (Wing et al., 1968; Wing

and Reitz, 1982).

2.2 Differential distribution

2.21 Spawn, larvae, and juveniles

Epinephelus striatus Eggs are released while fish are in

spawning aggregations that form annually at highly specific sites and times (Sections 3.13 and 3.16). Spawning

6 Odum, W. E., C. C. McIvor, and T. J. Smith III. 1982. The ecology of

the mangroves of southern Florida: a community profile. U. S. Fish

Wild. Serv. Biol. Serv. FWS-OBS-81/24, 144 p.

has not been recorded outside of spawning aggregations.

About 60–80 aggregation sites are known, mostly from

insular areas (Table 1, Figs. 5A and B), although many

no longer form (Section 5.43).

Spawning aggregation sites typically occur near the

edge of insular platforms, as little as 350 m from the

shore, and close to a drop-off into deep water over a

wide (6–50 m) depth range and diversity of substrate

types. Sites are characteristically small, highly circumscribed areas, measuring several hundred meters in diameter, with soft corals, sponges, stony coral outcrops,

and sandy depressions (Craig, 1966; Smith, 1972;

Burnett-Herkes, 1975; Olsen and LaPlace, 1979; Colin

et al., 1987; Carter, 1989; Fine, 1990; Beets and Friedlander, 1992; Colin, 1992; Aguilar-Perera, 1994).

Nassau grouper larvae are rarely reported from offshore waters (Leis, 1987) and little is known of their

movements or distribution, other than limited data on
8 NOAA Technical Report 146

Figure 4

Geographic distribution (indicated by the solid line) of the jewfish, Epinephelus itajara, in

the western and eastern Atlantic and the eastern Pacific (redrafted from Heemstra and

Randall, 1993).

settlement patterns. Currents in the vicinity of aggregation sites do not necessarily favor offshore egg transport,

leaving open the possibility that some stocks are partially self-recruiting. For example, drogues (floats which

drift with water currents) deployed near gametes at eastern Long Island, Bahamas, moved little from the shelf

edge for several days immediately following spawning

and one ended up inshore (Colin, 1992). Collections of

pelagic larvae were made 0.8–16 km off Lee Stocking

Island, Bahamas, at 2–50 m depths and from tidal channels leading onto the Exuma Bank (Greenwood, 1991).

Inshore samples were taken during the day and offshore

samples at night (Greenwood, 1991).

Small juvenile Nassau grouper are common in shallow seagrass beds, macroalgae, and around clumps of

Porites spp. coral (Randall, 1983; Eggleston, 1995). Juveniles settle into the interstices of macroalgal clumps,

remaining several months before associating with other

microhabitats in macroalgal beds. Monthly repeated

censuses of a cohort indicated that juvenile density decreased sharply after settlement, until fish emerged from

algal habitat at several months of age, and thereafter

remained relatively constant (Dahlgren, 1998). They are

also found in deeper water banks and offshore reefs

(Tucker et al., 1993; Colin et al., 1997) and recruit to

artificial reefs (Beets and Hixon, 1994). Recently settled

Nassau grouper were collected from tilefish, Malacanthus

plumieri, rubble mounds at 18 m or associated with discarded queen conch, Strombus gigas, shells and other

debris around Thalassia beds (Wicklund7). In the Bahamas, abundance of late-larval to early-juvenile Nassaus

was substantially higher in macroalgae (mainly Laurencia

spp.) than in seagrass, probably as a result of active selection for macroalgae to avoid high post-settlement

predation in seagrass beds (Nadeauand Eggleston, 1996;

Nadeau8). Juveniles shifted from the macroalgal habitat to natural and artificial patch reefs over a 3-month

period at 120–150 mm total length (TL) (Eggleston,

7 Wicklund, Bob. 1990. Caribbean Marine Research Center, Vero

Beach Laboratory, 805 East 46th Place, Vero Beach, FL 32963. Personal commun.

8 Nadeau, David A. 1996. MEAS Dept., North Carolina State University, Box 8208, Raleigh, NC 27695-8208. Personal commun.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 9

Table 1A

Locations and contemporary status of Nassau grouper, Epinephelus striatus, spawning aggregations. Approximate number

of aggregations known for each region is indicated in parentheses (modified from Sadovy, 1997; also Claro, text footnote

15; Thompson, text footnote 39; Ward, text footnote 45).

Region Location Status

Bahamas (23) Andros Island Heavily exploited

Bahamas Long Island Declines noted

Bahamas Cat Cay/Bimini Active but intermittent

Belize (6) Cay Glory Threefold decline over thirty years

Belize Lighthouse Reef Active

Belize Ambergris Point Disappeared

Bermuda (3) Three sites Disappeared

Cayman Islands (5) Three major sites Recent declines

SE Cuba (4)1 Cabo Cruz Disappeared

SW Cuba Cayo Cuano Declining landings

NW Cuba San Carlos Disappeared

Dominican Republic (1) Punta Rusia Possibly disappeared

Honduras (1) Bay Islands Fiftyfold decline over three years

Mexico (7) Majahual Declines since the 1970s

Mexico Xahuaxhol Active

Puerto Rico (3) Mona Island Disappeared

Puerto Rico S and SW coasts Disappeared 1970-80s

U.S. Virgin Is. (3) St. Thomas/St. Croix Disappeared in 1970s/1980s

British Virgin Is. (4) Status unknown

1 As many as 21 aggregations were noted in the 19th century in Cuba (Vilaro Diaz, 1884) although contemporary status is unknown (see

Table 1B).

1995). On shallow artificial reefs in the Virgin Islands,

30–80 mm TL juveniles occupied small burrows beneath

the reef while larger juveniles occupied holes in the reefs

(Beets and Hixon, 1994). Schools of 30–40 juveniles

(250–350 mm TL) were observed at 8–10 m depth in

the Cayman Islands (Tucker et al., 1993).

Epinephelus itajara Off the southwest coast of Florida,

groups of jewfish form periodically around shipwrecks,

rock ledges and isolated patch reefs down to 45 m depths

(Eklund, personal observ.). These aggregations are presumably for spawning, although actual spawning has not

been observed. Off Hobe Sound, southeast Florida, an

aggregation of 24 jewfish, which used to assemble in 5 m

of water, no longer forms at this site (William Parks cited

in Gulf of Mexico Fishery Management Council

[GMFMC]9). Historically, an aggregation occurred off

Palm Beach, also southeast Florida, but that aggrega9 Gulf of Mexico Fishery Management Council (GMFMC). 1990.

Amendment Number 2 to the Fishery Management Plan for the

Reef Fish Fishery of the Gulf of Mexico, 31 p.

tion has also disappeared (South Atlantic Fishery Management Council [SAFMC]10). Aggregations are known

off Belize and Colombia (Section 3.16) (Fig. 6). Distribution of jewfish larvae is unknown.

Jewfish juveniles have been collected from inshore,

shallow (2–3 m) habitats, including mangrove swamps,

bulkheads and bridges, and in poorly oxygenated canals (Springer and Woodburn, 1960; Tabb and Manning,

1961; Lindall et al., 1975; Thompson and Munro, 1978;

Bullock and Smith, 1991). Small young-of-the-year (46–

88 mm SL) appear in grass beds and estuaries off Florida

from November through January, indicating a summer

spawning period (Bullock and Smith, 1991). In southwestern Puerto Rico, six larvae (14.7–17.9 mm SL) were

taken in mangrove areas by night-light in mid-September 1988, indicating recent spawning (Dennis et al.,

1991).

10 South Atlantic Fishery Management Council (SAFMC). 1990.

Amendment Number 2, Regulatory Impact Review, Regulatory

Flexibility Analysis and Environmental Assessment for Fishery Management Plan for the Snapper Grouper Fishery of the South Atlantic Region, 47 p.
10 NOAA Technical Report 146

Table 1B

Details of aggregation sites of Epinephelus striatus noted in Cuba and the Bahamas which, between them, include about 50%

of all sites recorded. Unpublished sites in the Bahamas reported by fishermen and fishing vessel captains in 1992 (Source:

Colin Higgs, Department of Fisheries, Government of the Bahamas). Sites and spawning times in Cuba were noted in the

19th century (Vilaro Diaz, 1884) although it has not been possible to verify which sites were the same as contemporary ones

reported by Claro et al. (1990).

Location Spawning site Moon phase

Cuba

Matanzas Cayos Francés, Bahía de Cadíz Full moon

Mantua Cays and rocky areas Between full and new moons

Bahía Honda From Rancho del Obispo to Punta del Negro Between full and new moons

Isla de Pinos To the south, a mile from the reefs Full moon

San Cayetano From Cayo Blanco to Cayo Jutías —

Coloma — Full moon

Cárdenas Drop-off areas, especially Cayo Full moon

Bahía de Cadíz and Mono Grande

Habana — Between full and new moons

Cienfuegos East of Cayos de Las Doce Leguas, Cayo Blanco de Sasa, Punta de Piedras,

Los Jardines y Jardinillos, near shelf-edge Between new and full moons

Puerto Padre The entire district Between full and new moons

Gibara — —

Nuevítas Punta Rasa Between full and new moons

Caibarien Shelf-edge areas Between full and new moons

Punta Alegre From Cayo Francés to western Cayo Santa María Full moon

Batabanó All along the coast Full moon

Mariel Los Jardines and Jardinillos banks Full moon

Manzanillo — Full moon

Baracoa — —

Guantánamo — —

Cuba Specific banks Between new and full moons

Sagua — Between new and full moons

Bahamas1

Berry Islands Off Little Harbour Cay, 6 miles west2 of Little Stirrup Cay, Ginger Bread

Ground, NE and SW of Great Isaac Full moon

Bimini Off Dollar Harbour, Cat Cay Full moon

Andros Off High Cay2, off Tinker Rock2, off South Rock, south of Green Cay,

Sand Bores between Andros and Exuma Full moon

New Providence SW Reef Full moon

Ragged Island Double Breasted Cay Full moon

Long Island South End Point2, North Side Place, north end opposite Stella Maris Full moon

Cat Island North side opposite Arthur’s Town2 Full moon

Acklins Off Castle Island light Full moon

Eleuthera Six Shillings Channel, Booby Rock Channel, Ship Channel, off Powell Point Full moon

Exuma Off Sail Rocks2, North Exuma Cays Full moon

Cay Sal Off Anguilla Cays2 Full moon

1 Best fishing at Bahamas sites is reported three days prior to and three days after full moon between November to January; this implies

that full moon is probably the spawning period. Fig. 5B shows approximate locations of Bahamas sites.

2 Indicates sites identified as the main aggregation sites by the Bahamas survey.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 11

Figure 5

(A) Map indicating approximate locations of spawning aggregations of Nassau grouper, Epinephelus

striatus, that are still fished (closed star) and which no longer form (square) throughout its geographic

range. [Symbols may represent more than one aggregation in the general area indicated (updated

from Sadovy, 1997 - see Table 1 for more details).] (B) Map indicating approximate sites (represented

by black circles) of spawning aggregations in the Bahamas. See Table 1B for details.
12 NOAA Technical Report 146

Figure 6

Map indicating approximate locations of spawning aggregations of the jewfish, Epinephelus itajara, that

still have fish (closed star), for which current status could not be confirmed (open star), and which no

longer form (square). The site(s) in SW Florida has not been fished since 1990.

2.22 Adults

Epinephelus striatus No general distinction can be made

between adult and juvenile habitats, although a general

size segregation with depth occurs with smaller fish in

shallow inshore waters and larger individuals more common on deeper offshore banks (Bardach et al., 1958;

Cervigón, 1966; Silva Lee, 1974; Radakov et al., 1975; Thompson and Munro, 1978). The extent to which this pattern is caused by greater fishing intensity inshore, or by

differential movements of different-sized fish, is unknown.

Adults lead solitary lives outside of the spawning season,

rarely venturing far from cover (Böhlke and Chaplin, 1968;

Smith, 1971; Carter et al., 1994; Sluka et al.,1998).

Epinephelus itajara Jewfish occur either as solitary individuals or in groups of up to 100 in shallow water, typically in less than 40 m water depth (Eklund, personal

observ.). Zinkowski (1971), however, observed a group

of 20–30 individuals in a 90 m-deep cave, and Carpenter and Nelson (1971) caught jewfish off Panama, western Colombia, and the Guianas down to 55 m during

exploratory fishing in the Caribbean Sea. In Florida, this

species is often taken around docks and bridges and on

set-lines made fast to mangrove trees (Smith, 1971),

while in Jamaica, large adults were once captured in

Kingston Harbor (Thompson and Munro, 1978). Large

jewfish are sedentary and exhibit little inter-reef movement; Smith (1976) observed the same individuals for

more than a year at specific reef sites off Florida.

2.3 Determinants of distribution changes

Epinephelus striatus Primary determinants of distribution changes in Nassau grouper are not known although

water clarity, habitat, and substrate type appear to be

important (Smith, 1971; Eggleston, 1995). This species

is most abundant in clear waters of high-relief coral or rocky

reefs. Small juveniles are associated with macroalgae,

seagrass beds, or Porites clumps (Section 2.21). The depth

range of the Nassau grouper (0–100 m) may be influenced

more by the availability of suitable habitat than by food

resources, since diet is highly varied and more a function

of body size than of water depth (Section 3.41).

Since adults are known to migrate long distances to

reach spawning sites (Section 3.51), proximity to these

sites during non-reproductive periods is apparently not

critical although the sites themselves may be essential

for reproduction. It is probable that spawning sites are

quite specific and that their destruction or disturbance
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 13

could negatively impact spawning activity of population(s) that utilize such sites. In this respect, species

like the Nassau grouper, which may depend for their

reproduction on highly specific spawning areas, could

be severely habitat-restricted, the spawning sites forming significant bottlenecks in their life cycle. The loss of

local stocks following the elimination of local spawning

aggregations in a number of insular areas (e.g. Bermuda

and Puerto Rico) suggests that some populations are

partially self-recruiting, although further genetic studies are necessary to test this hypothesis (Section 1.33)

(Sadovy, 1993).

In the wild, the Nassau grouper spawns over a narrow

temperature range (25–26°C) which m‘= limit the northern and southern extremes of reproductive populations

and the timing of spawning migrations (Colin, 1992;

Tucker et al., 1993; Carter et al., 1994). It is also feasible

that distribution is influenced by the availability of suitable symbiotic cleaners (Section 3.53).

Epinephelus itajara Presence of mangrove areas appears

to be important for juvenile jewfish. Reports of jewfish

from the Lesser Antilles are particularly rare, probably

due to limited mangrove habitat. Holes and caves provide important shelter for adults.

3 ECONOMIC AND LIFE-HISTORY

3.1 Reproduction

3.11 Sexuality

Epinephelus striatus Like most other groupers, the

Nassau was originally considered to be a monandric

protogynous hermaphrodite, whereby all males derive

from the sex change of adult females (Smith, 1971; Claro

et al., 1990; Carter et al., 1994). Evidence of a change

from adult female to adult male in the Nassau (i.e. fish

undergoing sexual transformation whereby the gonads

show degeneration of mature tissue of one sex and proliferation of reproductive tissue of the other), however,

is weak (Sadovy and Shapiro, 1987; Shapiro, 1987).

Other characteristics are also inconsistent with a diagnosis of monandric protogyny such as the strong male/

female size overlap, the presence of males that develop

directly from the juvenile phase, and the mating system

(Section 3.16) (Colin, 1992; Sadovy and Colin, 1995).

Nassau grouper pass through a juvenile bisexual phase

(the gonads consist of both immature spermatogenic

and immature ovarian tissue) (Table 2), and mature directly as male or female (Sadovy and Colin, 1995). Although the Nassau grouper is capable of changing sex

following hormone injection—one Nassau grouper reproduced as a female and subsequently as a male apTable 2

Stages of gonadal maturation for 230 Epinephelus striatus

collected in the Bahamas between May 1988 and October 1990 (from Sadovy and Colin,1995—Fig. 3). Bisexual fish are those in which the gonads contain both

ovarian and testicular tissue and include both immature (both male and female tissue immature) and mature (in parentheses) bisexuals.

Female Male

Size class

(mm SL) Bisexual Immature Mature Immature Mature

151–200 1 1

201–250 2

251–300 8 3 1

301–350 11 3 1

351–400 15 2

401–450 4 1 2 1 1

451–500 9 10 23

501–550 4(1) 36 15

551–600 (3) 33 9

601–650 13 4

651–700 5 6

701–750 1 1

Total 58 10 100 1 61

11 Watanabe, Wade, and William Head. 1992. Caribbean Marine Research Center, Vero Beach Laboratory, 805 East 46th Place, Vero

Beach, FL 32963. Personal commun.

proximately 6 months later, following an LHRH-a implant in captivity (Watanabe and Head11, Watanabe et

al., 1995a)—natural sex change has not been confirmed.

The close affinity of this species with other hermaphroditic serranids accounts for the gonad structure of this

species (Section 3.15) and although it may retain a capacity for natural sex change, available evidence indicates that this is not typical and that the Nassau grouper

is primarily gonochoristic (separate sexes) (Sadovy and

Colin, 1995).

Epinephelus itajara There is no conclusive evidence

regarding the sexual pattern of the jewfish (Bullock et

al., 1992), although protogynous hermaphroditism has

been suggested due to the presence of regressive oocytes of unspecified maturation stage within the testis

of a 1,602 mm SL male (Smith, 1959, 1971). Bullock

and Smith (1991) and Smith (1971) examined testes

with a lumen and peripheral sperm-collecting sinuses

(features often found in protogynous species) but also

noted a number of small (relative to females) (887 mm

SL) mature males, indicating that some males mature

directly as males. The evidence is insufficient to con-
14 NOAA Technical Report 146

firm hermaphroditism and discount gonochorism

(Sadovy and Shapiro, 1987). Of 481 jewfish examined,

none were undergoing sexual transition, males and females overlapped in size, and the sex ratio did not differ from unity.

3.12 Maturity

Epinephelus striatus Male and female Nassau grouper

typically mature between 400 and 450 mm SL, with most

individuals attaining sexual maturity by about 500 mm

SL and 7 years (Table 3), although the smallest mature

fish recorded in Cuba was a male in the 360–390 mm

TL size class (Claro et al., 1990). From otolith ageing

work, the minimum age at sexual maturity is between 4

and 8 years (Bush et al., in press) with most fish spawnTable 3

Summary of life history parameters for Nassau grouper, Epinephelus striatus, and jewfish, E. itajara. The area and source are

indicated in parentheses, where known.

Epinephelus striatus Epinephelus itajara

Age and length 5 yrs, 580 mm SL (Virgin Islands) 6-7 yrs, 1200-1350 mm TL females; 4-6 yrs,

at maturity (Olsen and LaPlace, 1979) 1100-1150 mm TL males (E. Gulf of Mexico)

(Bullock et al., 1992)

420-450 mm SL females

400-450 mm SL males\4+ yrs

(Cayman Islands) (Colin et al., 1987;

Bush et al., in press)

500 mm TL (minimum size ripe males)

(Cayman Islands) (Tucker et al., 1993)

425 mm SL females; 402 mm SL males, immatures

are 3-6 yrs (otolith growth zones not validated)

(Bahamas) (Sadovy and Colin, 1995)

483 mm TL (North Carolina-Florida)

(SAFMC, text footnote 24)

480 mm TL (Jamaica)

(Thompson and Munro, 1978)

Age and length < 300 mm TL & 4-5 yrs (Virgin Islands) 508 mm (Gulf of Mexico)

at first capture (Olsen and LaPlace, 1979; CFMC, (GMFMC, text footnote 9)

text footnote 26)

6-7 yrs (Cayman Islands) (Bush et al., in press)

275-625 mm TL (mean = 570) (Jamaica)

(Thompson and Munro, 1978)

300-500 mm TL depending on size limits

(North Carolina-Florida) (SAFMC, text footnote 46)

450 mm TL (South Florida) (Bohnsack, 1990)

Maximum age 1200 mm TL (CFMC, text footnote 26) 2400 mmTL (Virgin Islands)

and length 9 yrs, 910-960 mm SL (Olsen and LaPlace, 1979) (CFMC, text footnote 26)

(Virgin Islands)

17 yrs, 710 mm TL, 6700 g (Cuba) 37 yrs, 2155 mm TL females 26 yrs, 2057 mm TL

(Claro et al., 1990) males (E. Gulf of Mexico) (Bullock et al., 1992)

755 mm SL (Bermuda) (Bardach et al., 1958) 2500 mm TL (Heemstra and Randall, 1993)

840 mm TL (Jamaica) (Thompson and Munro, 1978)

640 mm TL (Netherlands Antilles) (Nagelkerken, 1981)

29 yrs, 850mm FL (Cayman Islands) (Bush et al., in press)

ing by age 7+ years (Olsen and LaPlace, 1979; Bush et

al., in press). Nassaus raised from the egg in captivity

matured at 27–28 months (400–450 mm SL) (Tucker

and Woodward, 1994). Thus size, rather than age, may

be the major determinant of sexual maturation.

Epinephelus itajara Sexual maturity in jewfish from the

eastern Gulf of Mexico was determined histologically

(Bullock et al., 1992) (Table 3). Males matured at a

smaller size and somewhat younger age than females.

Males <1,150 mm TL were immature with 50% mature

by 5–6 years. All males larger than 1,155 mm TL and

older than 7 years were mature. Female jewfish first

mature at 1,200–1,350 mm TL and 6–7 years; all females

larger than 1,225 mm TL and older than 6 years were

mature (Bullock et al., 1992).
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 15

3.13 Mating

Epinephelus striatus The reproductive season in the

Nassau grouper is brief and evidently associated with

temperature and moon phase, according to GSI, gonadal

histology, macroscopic, and oocyte diameter analyses.

At lower latitudes, reproductive activity lasts for about

one week per month, for one to three months each year,

between December and February (Fig. 7), either peaking in January (Smith, 1972; Olsen and LaPlace, 1979;

Claro et al., 1990; Colin, 1992; Powell and Tucker, 1992;

Aguilar-Perera, 1994; Miller12) or between January and

April (Thompson and Munro, 1978). In more northerly latitudes (i.e. Bermuda and Florida), the reproductive season falls between May and August, peaking in

July (Oliver La Gorce, 1939; Smith, 1971; Burnett-Herkes,

1975). Exceptions to the possible latitudinal pattern were

the capture of recently spawned females in September in

Cuba and the observation, in the same month, of a school

of Nassau grouper at 29 m depth exhibiting probable

spawning behavior in this location (Claro et al., 1990).

All spawning, as far as is known, occurs in distinct aggregations. Neither aggregation nor spawning have been

reported from South America although ripe Nassaus are

Figure 7

Monthly distribution of percent frequency of different gonad development stages for

female Nassau grouper, Epinephelus striatus, collected from Belize from 1984–86 (n=1,232)

(redrafted from Carter et al., 1994).

12 Miller, W. 1984. Spawning aggregations of the Nassau grouper,

Epinephelus striatus, and associated fishery in Belize. Advances in

Reef Sciences, October 26–28, 1984, University of Miami, Florida.

Unpubl. data, p. 19.

frequently taken (Cervigón13). Aggregation spawning is

likewise unknown from the Lesser Antilles, from Central America south of Honduras, or from Florida, despite

commercial landings in many of these areas. Whether these

reports indicate a different spawning strategy, or loss of

aggregations that once formed, is not known.

Spawning in the wild is highly synchronized and occurs briefly within about a week of full, or between full

and new, moon (Smith, 1971; Colin, 1992; Tucker et al.,

1993; Aguilar-Perera, 1994; Carter et al., 1994; Tucker

and Woodward, 1994; Department of Fisheries, Government of the Bahamas), within the narrow temperature

range of 25–26°C and over a wide range of daylengths

(Colin, 1992; Tucker et al., 1993; Carter et al., 1994) (see

also Section 7). Similar associations between reproduction,

temperature, and lunar phase were also noted in captive

animals. Nassau grouper raised from egg to maturity in

Florida and Bermuda under conditions of ambient light,

temperature, and salinity, exhibited ovarian maturation,

ovulation, behavior, and color changes characteristic of

spawning, at 26°C, although no spawning was observed

(Tucker and Woodward, 1994). Temperature is evidently

a more important stimulus for spawning than day length,

according to patterns of voluntary spawning in captive fish;

while spawning occurred at temperatures ranging from

13 Cervigón, Fernando. 1991. Fundacion Cientifica Los Roques,

Aptdo. 1139, Caracas 1010A, Venezuela. Personal commun.
16 NOAA Technical Report 146

23.1–27.9°C, 24–27°C was the most suitable

based on spawning frequency and volume,

and egg and larval development (Tucker,

1994; Watanabe et al., 1995b; Tucker et al.,

1996). Nassau grouper spawned spontaneously one day prior to the new moon in April

1963 in an aquarium in Cuba under artificial light and water temperature of 24.9°C

(Guitart-Manday and Juárez-Fernandez,

1966).

Epinephelus itajara The reproductive

season of the jewfish occurs between June

and October but, as for the Nassau grouper, varies with geographic location. Jewfish in the eastern Gulf of Mexico have

ripe gonads from June through September, with peak activity indicated from July

through September (Bullock et al., 1992)

(Figs. 8A and B). Presumed courtship activity was observed in small groups (8–12)

of jewfish off southwestern Florida in August and September around the time of

the full moon, although no spawning was

observed (Colin, 1994). Jewfish (known

locally as the “June Fish”) in Belize

spawned inshore in creeks, estuaries, and

lagoons in July and August. In Puerto

Rico, ripe individuals appeared in July and

August (Erdman, 1976). In Colombia, the

main spawning season is believed to be in

September and October (Carlos A.

Bohorquez cited in Colin, 1989).

3.14 Fertilization

Figure 8

Monthly distribution of gonad classes for mature (A) female (n=86)

and (B) male (n=66) jewfish, Epinephelus itajara, collected from the

eastern Gulf of Mexico (redrafted from Bullock et al., 1992)

Epinephelus striatus See Section 3.21.

Epinephelus itajara No information available.

3.15 Gonads

Epinephelus striatus As in other epinepheline serranids,

Nassau gonads consist of a bilobate, hollow sac lying

below and posterior to the air bladder and connected

to it by mesenteries (Smith, 1965). The lobes of the ovary

are unequal in size and fused posteriorly with the lumina forming a common oviduct which descends to the

genital region immediately behind the anus. The urinary bladder and its duct are closely bound to the posterior face of the common oviduct. There is no germinal epithelium in the common oviduct and the wall of

the gonad is composed of smooth muscle and connective tissue (Smith, 1965; Carter et al., 1994). Possible

endocrine tissue masses of the type described in other

serranids (e.g. Lavenda, 1949; Smith, 1965) are visible

close to the main vein and artery in juveniles and adults

(Sadovy and Colin, 1995). All ovaries and testes have a

lumen with an alamellar region located laterally in juveniles and ventrally in adult males and females (Carter

et al., 1994; Sadovy and Colin, 1995). The testicular organization is of the “unrestricted spermatogonial testistype” (Grier, 1981).

Gonadosomatic indices (GSI), calculated for ripe testes and ovaries, are similar for males and females with a

maximum GSI of 19% for a hydrated female and 16%

for ripe males (Tucker et al., 1993; Carter et al., 1994;

Sadovy and Colin, 1995). The high male GSIs of the

Nassau grouper are noteworthy in that they are uncharacteristic of grouper species wherein ripe male GSIs are

typically low compared to those of ripe females (Sadovy

et al., 1994). The high GSI of ripe Nassau males is indicative of sperm competition (e.g. Choat and Robert-
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 17

son, 1975) among males that spawn in small groups,

one female to several males; this mode of spawning

has not been described in any other grouper (Section

3.16). Ripe females can be identified by a distended

abdomen and a characteristic bulge between the anus

and the urinary papilla (Tucker et al., 1991).

Epinephelus itajara The ovaries of jewfish have not

been described. Testes exhibit a lumen and peripheral sperm sinuses and contain remnants of many

ova (Smith, 1959, 1971; Bullock and Smith, 1991).

Few data are available on GSI of jewfish since specimens have often been gutted by the time they are examined. Four males, ranging in length from 1,610–

1,935 mm TL (92.3–155.5 kg), had ripe testes weighing from 0.68–2.00 kg and GSIs of 0.59–1.46%, while

the largest ovary weighed was 16.36 kg (Bullock14).

3.16 Aggregation and spawning

Epinephelus striatus The Nassau grouper aggregates

in large numbers to spawn each year. As far as is

known, all reproductive activity occurs in these aggregations that form consistently at specific sites

(= grouper “holes”) and times. Aggregations consist of hundreds, thousands, or even tens of thousands of individuals and have persisted at known

locations for periods of 50 years or more (Smith,

1972; Olsen and LaPlace, 1979; Colin et al., 1987;

Fine, 1990, 1992; Colin, 1992; Carter et al., 1994;

Sadovy, 1997; Claro15) (see also Section 5.43).

Aggregations form at depths of 6–50 m (Section

2.21), as a column or cone of fish of different color

phases rising to within 17 m of the water surface

(Olsen and LaPlace, 1979; Carter, 1986; AguilarPerera and Aguilar-Dávila, 1996). Prior to spawning,

individuals mill around over the substrate exhibiting one of four distinctive color phases: (1) barred

(normal) (Fig. 9A); (2) bicolor (Fig. 9B); (3) white

belly (Fig. 9C); or (4) dark phase (Fig. 9D). There

are intergradations of these patterns, with rapid

changes among patterns possible (Colin, 1992). The

barred color phase is found among fish in the aggregation in the morning. The bicolor phase, first

described by Smith (1972), occurs in both males and

females and is dominant during the late afternoon

with most fish becoming bicolored by dusk, when

spawning occurs (Colin, 1992). In this phase, the

upper body and head become dark while the belly,

lower sides, lips, and all fins but the dorsal are white.

A white eyebar is prominent on the head (Colin,

14 Bullock, Lew. Florida Marine Research Institute, 100 8th Avenue, SE, St. Petersburg, FL 33701. Unpubl. data, 13 p. 15 Claro, Rodolfo. 1991, Laboratory of Fish Ecology, Institute of

Oceanology, #18406 Playa, Havana, Cuba. Personal commun.

Figure 9

Color phases exhibited by the Nassau grouper, Epinephelus striatus:

(A) typical barred coloration; (B) bicolor phase; (C) white belly

phase; (D) dark phase.
18 NOAA Technical Report 146

1992). In the white belly phase, seen

among presumed females with bulging abdomens (probably full of ova),

the normal color pattern is modified

such that the abdominal area is distinctly white (Colin, 1992). The last

pattern, the “dark” phase, is found

in courting and spawning fish; the

body and fins become dark gray to

black with the barred pattern visible

beneath the dark pigmentation.

These fish are probably females

ready to spawn since they appear to

lead group-spawning events (see below) (Colin, 1992).

Courtship is indicated by two behaviors which occur late in the afternoon: “following” and “circling”

(Colin, 1992): “following” occurs as

one or more fish in the bicolor phase

swim closely behind an apparent female; “circling” occurs as a bicolor

phase fish circles a barred or dark

phase fish. Progression from courtship to spawning may depend on

aggregation size but generally occurs

as follows. Towards the late afternoon fish move progressively higher

in the water column, with an increasing number exhibiting the bicolor

phase (Colin, 1992; Carter et al.,

1994). The aggregation then moves

into deeper water shortly before

spawning (Colin, 1992; Tucker et al.,

1993; Carter et al., 1994) by which

time all individuals are either “dark

phase” or “bicolor”. Bicolor fish then

follow dark phase fish closely and

group-spawning occurs in sub-groups

of 3–25 fish, apparently led by a “dark

phase” fish followed by a varying number of bicolor fish. Smaller aggregations tend to include fewer bicolor

phase fish and general activity and

color changes are less intense (Colin,

1992; Aguilar-Perera and AguilarDávila, 1996).

Spawning involves a rapid horizonFigure 10

Spawning behavior in the Nassau grouper, Epinephelus striatus: (1) fish start to move

up into the water column and an increasing number take on the bicolor phase; (2)

ascent by a small sub-group led by a dark-phase individual followed by bicolors; (3)

release of sperm and eggs; (4) rapid return of fragmented sub-group to the substrate (description from Colin, 1992); figure reproduced from Sadovy (1996), with

permission from Chapman & Hall Publishers.

tal swim followed by a circling ascent of small sub-groups

into the water column, with release of sperm and eggs

and a rapid return of the fragmented sub-group to the

substrate (Fig. 10). On the basis of observations of over

50 spawning events, the earliest and latest spawnings

occurred within 20 minutes of sunset and most within

10 minutes of sunset (Colin, 1992) (Fig. 11). Hydration

of vitellogenic eggs occurs in the afternoon shortly before spawning (Fig. 12).

Although aggregations form more than once at a particular site during a reproductive season, it is unclear

whether the same individuals participate each time.

However, several females from one aggregation contained ripe and sub-ripe oocytes together with post-ovu-
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 19

Figure 11

Frequency and timing of spawning by the Nassau grouper, Epinephelus

striatus, at two aggregation sites (SP=South Point; LH=Little Harbor)

off Long Island, Bahamas. The horizontal line indicates the observation period and all lines are adjusted so that sunset occurs at the same

relative time (from Colin, 1992).

latory follicles (which remain after mature

oocytes have been released), suggesting

that individual females spawn repeatedly

on different days during one aggregation

(Smith, 1972; Sadovy, personal observ.).

Moreover, examination of spawning on

videotape indicated that during 3–4 successive gamete releases by a sub-group

within a 15–20 second period, the same

female led all spawning events, again indicating multiple egg releases in one evening

(Colin, 1992). No data are available, however, addressing whether each mature female spawns in every aggregation month,

or indeed, each year (but see Section

3.51).

It is not known how Nassau grouper select and locate aggregation sites or why

they aggregate to spawn. To locate a site,

this species could swim up- or down-current along the shelf break to reach the

most seaward upcurrent extension of the

reef where aggregation sites are generally

located (Carter, 1986; Colin et al., 1987)

(Section 2.21). The timing and synchronization of spawning may be determined

by the necessity for widely dispersed adults

to coordinate their reproductive activities,

may facilitate egg dispersal, or minimize

predation on adults or eggs (Colin, 1992).

Prior to spawning, fish migrate toward

aggregation sites in groups numbering between 25 and 500, moving parallel to the coast or along

the shelf edge (Colin, 1992; Carter et al., 1994; AguilarPerera and Aguilar-Dávila, 1996). “Corridas de desove”

(spawning runs), which refer both to the migration of

fish toward a spawning site and to the aggregation itself, were first described in Nassau grouper from Cuba

in 1884 by Vilaro Diaz, and later by Guitart-Manday and

Juárez-Fernandez (1966). All three workers noted that

fishers reported “corridas” occurring mainly between

November and February and at different moon phases.

It is not known whether “corridas” are exclusively associated with spawning or occur at other times, unassociated with reproductive activity.

Epinephelus itajara Jewfish appear to aggregate in

greater numbers when reproductively active than in nonreproductive periods and are therefore believed to

aggregate to spawn. Aggregation sites are known only

from Belize, southeast and southwest Florida (Atlantic

and Gulf of Mexico waters), and Colombia (Fig. 6). An

aggregation at English Cay, southeast of Belize City,

Belize, consisted of 50–60 individuals and formed sometime between June and October (Domeier and Colin,

1997; Auil16). Females at these aggregations had advanced vitellogenic oocytes and males contained running milt indicating recent or imminent spawning. In

Colombia, jewfish aggregate in September and October

(Carlos A. Bohorquez cited in Colin, 1989). In southwest Florida, they aggregate in August and September

on shipwrecks in 30–45 m of water (Eklund, personal

observ.).

Aggregations during the reproductive season typically

number from a few fish to more than 100 individuals, although many have declined in fish number in recent years

(see also Section 4.2). About 20–30 large jewfish (45–200

kg) were reported in June 1971 at a wreck at 36 m depth

off southwest Florida (Smith, 1976) and adults have also

been observed by divers on offshore wrecks at depths of

36–46 m (Bullock and Smith, 1991). At aggregation sites

off southwest Florida (30–40 m depth) number of fish declined from 25–150 in 1982–83, to 0–5 in 1989 (DeMaria17),

16 Auil, Stephanie. 1991. University of the West Indies, P.O. Box 863,

Belize City, Belize. Personal commun.

17 DeMaria, Don. 1990. P.O. Box 420975, Summerland Key, FL 33042.

Personal commun.
20 NOAA Technical Report 146

increasing again following the moratorium on capture; 13

sites have been noted (Koenig et al.18).

Details of behavior are known from southwest Florida

aggregation sites. Colin (1994) observed 8–12 large jewfish (60–150 kg) at 33 m depth on a wreck. Two of the fish

were present for both August and September observations.

Courtship was most common from late morning to midafternoon. Presumed males (sexes could not be verified

Figure 12

Oocyte diameter frequencies taken in (A) the morning

(SL=508 mm) and (B) the afternoon (SL=551 mm) of

22 December 1988 during the spawning season of the

Nassau grouper, Epinephelus striatus, from the Bahamas

from two reproductively active females. Vitellogenic

oocyte diameters range from 0.17-0.71 mm and hydrated

oocytes are greater than 0.71 mm. [Figure prepared by

Pat Colin, Yvonne Sadovy, and George Mitcheson as part

of a project supported by the Caribbean Marine Research Center, National Undersea Research Program,

NOAA; P. Colin - project leader.]

18 Koenig, C., F. Coleman, and A. M. Eklund. 1997. Studies of the

jewfish (Epinephelus itajara) in the eastern Gulf of Mexico. Unpubl.

report to The Curtis and Edith Munson Foundation, 26 p.

but were assigned on the basis of color and behavior) exhibited a pale head and dark body coloration when courting (Colin, 1994), while presumed females did not change

color during courtship. Courtship consisted of a male nuzzling the vent area of females and of males and females

rising and turning together in the water column. Loud,

low frequency sounds (booms) were emitted, possibly related to courtship and territorial defense (Colin, 1994).

Intense interactions, including vent nuzzling, between fish

have been observed when they are “stacked” in layers off

the bottom in a well-defined mass (Koenig et al.18).

3.17 Spawn

Epinephelus striatus Fertilized eggs are pelagic, measure

about 1 mm in diameter, and have a single oil droplet

of 0.22 mm diameter (Guitart-Manday and JuárezFernandez, 1966). Artificially fertilized eggs are neutrally

(at 32‰) or positively buoyant and measure 0.9 to just

over 1 mm in diameter, with a single oil globule averaging 0.24 mm (Colin, 1992; Powell and Tucker, 1992).

Following voluntary spawning under artificial conditions, sperm were collected and described as having a

“piriform” cephalic portion and an extraordinarily long

tail (Guitart-Manday and Juárez-Fernandez, 1966).

Epinephelus itajara No information.

3.2 Preadult phase

3.21 Embryonic phase

Epinephelus striatus Eggs hatch 23 to 40 hours following fertilization. Embryonic development of eggs produced in a Havana aquarium was followed from fertilization to absorption of the yolk sac at 2.8 mm TL (72

hours); eggs hatched in about 40 hours at 25°C (GuitartManday and Juárez-Fernandez, 1966). Artificially fertilized eggs hatched within 27–29 hours of fertilization at

25°C, 23–25 hours at 28°C (Powell and Tucker, 1992), and

24 hours in ambient water temperature (Colin, 1992).

Epinephelus itajara No information.

3.22 Larval and juvenile phases

Epinephelus striatus Larval and early juvenile phases are

well described for the Nassau grouper. Newly hatched

larvae from induced spawnings measured 1.7–1.8 mm

notochord length (NL) (Powell and Tucker, 1992). Larvae had pigmented eyes 48 hours post-hatching and began feeding within 60 hours (Tucker et al., 1991). Development is described for laboratory-reared specimens from

the egg to a 13.5 mm SL larva approximately 40 days posthatching (Powell and Tucker, 1992) (Figs. 13A–13G). Fins
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 21

Figure 13

Developmental stages of laboratory-reared Nassau grouper, Epinephelus striatus: (A) 2.5 mm NL

early yolk-sac larva, 1 day old; (B) 2.6 mm NL late yolk-sac larva, 3 days old; (C) 2.9 mm NL

preflexion larva, 5 days old; (D) 4.9 mm NL early flexion larva, 13 days old. On facing page: (E)

6.2 mm NL late flexion larva, 20 days old; (F) 6.8 mm SL postflexion larva, 25 days old; (G)

postflexion larva, 13.5 mm SL, 40 days old (with permission from Powell and Tucker, 1992).
22 NOAA Technical Report 146

Figure 13 (continued)
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 23

develop in the order of pelvic, first dorsal, caudal, pectoral, anal, and second dorsal. The adult complement of

principal caudal fin rays was attained at 6.0 mm SL and

of dorsal spines at the postflexion stage at approximately

6.6 mm SL with completion of first and second dorsal

and anal fins at 7.4 mm SL. Preflexion larvae become

flexion larvae over the range of 5.0–5.4 mm NL and flexion to postflexion occurs between 6.0 and 6.5 mm NL

(Powell and Tucker, 1992). Larvae were planktonic until 42–70 days post-hatching with transformation occurring in less than one week (Powell and Tucker, 1992;

Tucker and Woodward, 1994).

Newly hatched larvae are inconspicuously pigmented

and slightly curved around the yolk sac when artificially

reared (Powell and Tucker, 1992). Wild-caught larvae

exhibit several small, dendritic melanophores on the

snout (Smith, 1971; Laroche19) (Fig. 14A). Yolk-sac larvae with a developing mouth have a characteristic pigment pattern in the form of a distinct “inverted saddle”

on the ventral midline and lateral surface of the caudal

peduncle (Figs. 13A–G) (Powell and Tucker, 1992) and

specimens <21 mm SL also lack the caudal peduncle blotch

which is found in all fish >35 mm (Smith, 1971). Pigment

patterns change markedly during the flexion stage, and

young postflexion larvae (<6.8 mm SL) are similar to late

flexion larvae. In small juveniles there is a characteristic

line of black spots along the bases of the dorsal rays posterior to the fifth spine (Smith, 1961) (Figs. 13G and 14B).

The pattern of vertical bars seems to develop at about 40

mm in specimens from the Bahamas (Smith, 1961).

It is highly unlikely that preflexion and flexion

epinepheline larvae can be positively identified as

Epinephelus striatus until a comparative study of epinepheline larvae is made, although certain combinations

of pigment, fin spinelets, and spine lengths narrow down

possibilities (Kendall, 1979; Johnson and Keener, 1984;

Powell and Tucker, 1992). With postflexion larvae

greater than 7.4 mm SL it is possible to separate Nassau

grouper from other groupers, except for E. adscensionis,

on the basis of dorsal and anal fin ray counts, spinelet

configuration, second first-dorsal-fin spine length relative to SL, and capture location (Powell and Tucker,

1992).

Larvae attain a maximum size of 30 mm SL (average

23.4 mm) by 36 days after presumptive spawning

(Shenker et al., 1993). Larvae collected 10 days after

probable spawning measured 6–10 mm SL. Over a 15-

day period, 8–22 days after the full moon, larval sizes

increased from 5.7 to 10 mm SL (Greenwood, 1991;

Shenker et al., 1993). Pelagic juveniles were collected

up to 46 days following a presumptive spawning moon,

and benthic juveniles were first found on artificial and

19 Laroche, Wayne. Stonefish Environmental and Taxonomic Services,

Box 216, Enosburg Falls, VT 05450. Unpubl. data.

natural reefs at 47 days. Pelagic juveniles taken in channel nets just prior to settlement measured 22–27 mm

SL (Colin, 1992; Colin et al., 1997) (Fig. 14C). Transition from larval to juvenile phases occurs at 6–7 weeks

for wild fish and 6–10 weeks for fish raised under artificial conditions from induced spawns. The wild-caught

larvae grew more slowly than larvae from induced spawns

(Shenker et al., 1993; Tucker and Woodward, 1994; Colin

et al., 1997).

Presumptive daily increments in lapilli of wild-caught

larvae indicate a larval period of 35–40 days and support fertilization at the full moon. A mean larval period

of 41.6 days was indicated from net-caught samples (Fig.

15) (Colin, 1992; Colin et al., 1997). Presettlement

otolith increments were distinct and easily counted,

however, settlement marks were not as apparent. It was

assumed that the first otolith increment forms after yolk

absorption, at least 4 days post-fertilization and three

days post-hatch, since larvae reared in aquaria up to the

stage of yolk sac absorption showed no evidence of increment formation (Colin et al., 1997).

Epinephelus itajara Little work has been done on jewfish larvae and none on the earliest stages. Larvae 6.2–

17.4 mm SL were examined and dorsal and pelvic spines

described in Johnson and Keener (1984). Larvae are

characterized by distinctive spinelet patterns on pelvic

and second dorsal spines and by a pigment spot at the

cleithral symphysis, found elsewhere only in E. cruentatus

and Mycteroperca spp. (Johnson and Keener, 1984).

Postflexion larvae captured around mangroves in southwestern Puerto Rico in September measured 14.7–17.9

mm SL, supporting the summer spawning period in that

area (Dennis et al., 1991) indicated by Erdman (1976).

3.3 Adult phase

3.31 Longevity

Epinephelus striatus The maximum age recorded for

Nassau grouper is 29 years, using sagittal otoliths from

the Cayman Islands (Bush et al., 1996; Bush et al., in

press) (Section 3.43) (Table 3). Using length-frequency

analysis, which tends to exclude younger animals, a theoretical maximum age at 95% asymptotic size is 16 years.

Other maximum age estimates include individuals of

up to 9 years in the heavily exploited Virgin Islands fishery (Olsen and LaPlace, 1979), 12 years in northern Cuba,

17 years in southern Cuba (Claro et al., 1990), and 21 years

from the Bahamas, assuming that rings are formed annually (Sadovy and Colin, 1995). These differences in maximum age estimates are probably due, in part, to methodological differences and, in part, to the effects of local fishing pressure. Individuals of more than 12 years of age are

not common in fisheries, with more heavily fished areas
24 NOAA Technical Report 146

Figure 14

Developmental stages of wild-caught Nassau grouper, Epinephelus striatus taken in the

Bahamas: (A) 9.1 mm SL taken 19 Jan 1991, tip of second dorsal spine slightly damaged; (B) 22 mm SL taken 3 Feb 1989; (C) 25 mm SL taken 2 Feb 1989 (Laroche19).
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 25

Figure 15

Pelagic life lengths (days) of the Nassau grouper, Epinephelus striatus,

determined from pelagic and benthic juveniles captured in the vicinity of Lee Stocking Island, Exumas, Bahamas, 1989 and 1990. Pelagic

life lengths were calculated from the number of pre-settlement otolith

increments in lapilli plus 4 days (approximate time between spawning

and first increment formation) (Colin et al., 1997, with permission).

yielding much younger fish on average. Generation time (the average age of parents in

the population) is estimated as 9–10 years

based on average fish size from an unexploited aggregaton in Belize (see Section

4.13), the growth curve from the Cayman

Islands (Fig. 16), and the SL-TL conversion

curve from Sadovy and Colin (1995).

Epinephelus itajara Maximum ages recorded for an exploited population of jewfish males and females, based on sagittal

otoliths, are 26 and 37 years respectively

(Table 3). Age range for 382 jewfish taken

from the eastern Gulf of Mexico was 3–26

years (n=41) for males, 0–37 for females

(n=85), and 0–36 for fish of undetermined

sex (n=256) (Bullock et al., 1992). Insufficient information is available to estimate

generation time.

3.32 Hardiness

Epinephelus striatus Under natural conditions the Nassau grouper appears to prefer

clear waters (Section 2.1) but is fairly tolerant of a range of water qualities: one adult

survived for more than seven years in the old

New York Aquarium in which the water at

times became nearly fresh and was frequently

quite polluted (Townsend, 1905).

Nassaus are considered to be hardy and

able to withstand handling and manipulation (e.g. Jordan, 1917). One 8.6 kg female

lay on a dry boat deck in the sun for more

than two hours before receiving an HCG

injection and ovulating (Tucker et al.,

1991). Both male and female brooders withstood handling during induced spawning

(Watanabe et al., 1995a). Several naive individuals, raised from the egg under artificial conditions, survived at least 200 days

when released onto reefs at 31 months of

age (Roberts et al., 1995).

Epinephelus itajara The jewfish is one of

few groupers able to live in brackish water.

Small jewfish have been taken in poorly

oxygenated upland canals in the Tampa Bay

area (Lindall et al., 1975) but the species is

apparently vulnerable to stresses caused by

Figure 16

Observed ages (years) and total lengths (cm) for Nassau grouper,

Epinephelus striatus, aged using sagittal otoliths, from five Cayman Island spawning aggregations (n=479), 1987–92 (Bush et al., in press).

cold water (Gilmore et al., 1978) or red tide; Smith

(1976) recorded that populations of jewfish were much

reduced during a 1971 red tide and that dead individuals over 45 kg were often observed.

3.33 Competitors

Epinephelus striatus Little is published on either intraor inter-specific competition in Nassau grouper. Juve-
26 NOAA Technical Report 146

niles exhibit aggression towards similar-sized conspecifics and display interspecific aggression (Dunham20).

When two non-reproductive adults, or an adult and large

juvenile, encounter one another, the smaller fish acquires the bicolor pattern (Fig. 9B) described for aggregating fish (Section 3.16) in apparent submission,

then turns laterally and usually swims away (Colin, 1992;

Colin21).

Epinephelus itajara No information.

3.34 Predators

Epinephelus striatus Information on predation upon

groupers is largely lacking, although sharks attacked

Nassaus at spawning aggregations in the Virgin Islands

(Olsen and LaPlace, 1979) and there is one report of

cannibalism in this species (Silva Lee, 1974). No predation was observed on spawning fish in the Bahamas, despite the presence of sharks in the area (Colin, 1992).

One mutilated fish was recovered, possibly attacked by

a barracuda or shark following release of tagged, laboratory-reared, naive individuals onto a reef in the Virgin Islands (Roberts et al., 1995). Early post-settlement

juvenile preferences for macroalgae over seagrass beds

is probably related, in part, to higher levels of predation in seagrass beds (Nadeau and Eggleston, 1996).

Epinephelus itajara Sharks have attacked juvenile jewfish that were caught on set lines in the mangrove shorelines of southwest Florida, in the Gulf of Mexico (Eklund,

personal observ.). No other information on predators

of jewfish has been documented.

3.35 Parasites, diseases, and abnormalities

Epinephelus striatus Parasites occur in both wild-caught

and cultivated Nassau grouper, predominantly in the

viscera and gonads. Encysted larval tapeworms are common in the viscera and a reddish-brown nematode occurs in the gonads (Thompson and Munro, 1978). Parasitic isopods are found in nostrils (Thompson and Munro,

1978). The digenetic trematodes Helicometra torta (pyloric

caeca), Lecithochirum parvum and L. microstomum (stomach),

and Sterrhurus musculus (stomach) were identified in

Florida-caught fish (Manter, 1947; Overstreet, 1969).

Diseases and abnormalities are not described. Although several species of western Atlantic groupers are

known to be ciguatoxic (especially when large), Nassau

groupers seem to be uniformly non-toxic throughout

their range (Halstead, 1967; Jory and Iverson, 1989) with

the interesting exception of one small toxic Nassau grouper in the Virgin Islands (Brownell and Rainey, 1971).

Excrescences were noted on otoliths and one fish had a

completely malformed sagittal pair with the whole of

the concave surface overgrown with a large excrescence

(Thompson and Munro, 1978).

Epinephelus itajara Parasites associated with the jewfish

include: trematoda—Lecithochirium microstomum, Prosorhynchus promicropsi, Stephanostomum promicropsi; nematoda—Heterotyphlum eurycheilum, Hysterothylacium sp.;

hirudinea—Trachelobdella sp.; isopoda—Excorallana

tricornis, Nerocila acuminata, Rocinela signata; copepoda—

Grandiungus promicrops, Tuxophorus caligodes (Bullock et

al., 1992). Breder and Nigrelli (1934) reported Myrichthys

acuminatus from the coelom of a jewfish. Vibrio parahaemolyticus was isolated from a single jewfish (Monsreal

and Flores-Abuxapqui, 1988).

From 1989 to 1991, 8 large jewfish (1,702–2,056 mm

TL) from southwest Florida and the Florida Keys were

found with average mercury concentrations exceeding

the U.S. Food and Drug Administration’s action level of

1 ppm methyl mercury. The range was between 0.42–

3.3 total mercury concentration, with a tendency for

larger individuals to have higher concentrations

(Henderson22).

3.4 Nutrition and growth

3.41/3.42 Feeding and food

Epinephelus striatus Groupers are unspecialized, bottom-dwelling, solitary predators (Randall and Brock,

1960; Randall, 1965). Feeding takes place throughout

the diel cycle although most fresh food is found in stomachs collected in the early morning and at dusk (Randall,

1967). Empty stomachs were also noted throughout

daylight hours (Silva Lee, 1974). Individuals feed by rapidly dilating the gill covers to engulf prey by suction

(Thompson and Munro, 1978; Carter, 1986) and take a

wide variety and size range of fishes and invertebrates,

both benthic and pelagic (Tables 4 and 5). With increasing age, there is a shift from consuming crustaceans to

taking fishes, larger bivalves, lobster, and gastropods (e.g.

Eggleston et al., 1998). However, the relationship between fish size and prey size shows much variation, with

large fish eating small prey and vice versa. For instance 20 Dunham, Jason. Caribbean Marine Research Center, c/o Florida a 580 mm FL Nassau grouper swallowed a 620 mm State Marine Laboratory, Rte. 1, Box 456, Sopchoppy, FL 32358.

Unpubl. report to the Caribbean Marine Research Center, 29

March, 1989.

21 Colin, Pat. 1990. Coral Reef Research Foundation, P.O. Box 1765,

Koror, Palau 96940. Personal commun.

22 Henderson, George. 1992. Florida Marine Research Institute, 100

8th Avenue, SE, St. Petersburg, FL 33701. Personal commun.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 27

Nekton

Fishes

Acanthuridae

Acanthurus sp.

Acanthurus coeruleus

Apogonidae

Atherinidae

Balistidae

Balistes vetula

Bothidae

Carangidae

Caranx ruber

Clupeidae

Harengula humeralis

Harengula clupeola

Jenkinsia lamprotaenia

Gerreidae

Gerres cinereus

Haemulidae

Haemulon aurolineatum

Haemulon flavolineatum

Haemulon album

Haemulon sciurus

Haemulon plumieri

Haemulon sp.

Holocentridae

Sargocentron vexillarium

Myripristis jacobus

Holocentrus rufus

Holocentrus sp.

Labridae

Halichoeres garnoti

Halichoeres bivittatus

Halichoeres sp.

Hemipteronotus sp.

Clepticus parrae

Lutjanidae

Lutjanus synagris

Lutjanus sp.

Ocyurus chrysurus

Monacanthidae

Monacanthus ciliatus

Monacanthus sp.

Cantherines pullus

Mullidae

Pseudupeneus maculatus

Muraenidae

Gymnothorax moringa

Gymnothorax sp.

Enchelycore nigricans

Lycodontis moringa

Muraena miliaris

Muraena sp.

Ostraciidae

Lactophrys sp.

Pomacentridae

Chromis cyanea

Chromis multilineata

Pomacentrus fuscus

Pomacentrus sp.

Abudefduf saxatilis

Microspathodon chrysurus

Priacanthidae

Priacanthus cruentatus

Scaridae

Sparisoma aurofrenatum

Sparisoma rubripinne

Sparisoma chrysopterum

Sparisoma sp.

Scarus vetula

Scarus croicensis

Scarus sp.

Serranidae

Hypoplectrus puella

Cephalopholis fulva

Epinephelus striatus

Synodontidae

Synodus intermedius

Synodus sp.

Urolophidae

Urolophus jamaicensis

Molluscs

Squids

Loligo sp.

Cuttlefish/octopi

Benthic animals

Molluscs

Gastropods

Strombus gigas

Strombus sp.

Fasciolaria tulipa

Bivalves

Barbatia cancellaria

Pelecypods

Crustaceans

Isopods

Stomatopods

Gonodactylus perstedi

Pseudosquilla ciliata

Squilla sp.

Shrimps/prawns

Alpheids

Carideans

Penaeids

Lobsters

Panulirus argus

Panulirus guttatus

Justitia longimana

Palinurellus gundlachi

Hermit crabs

Paguristes depressus

Petrochirus diogenes

Crabs

Calappa flammea

Calappa sp.

Stenorhynchus seticornis

Mithrax verrucosus

Mithrax cinctimanus

Mithrax sp.

Macrocoelema sp.

Petrolisthes galathinus

Chronus ruber

Portunus sebae

Portunus sp.

Xanthids

Grapsids

Table 4

Food items recorded in the stomachs of the Nassau grouper, Epinephelus striatus (from Randall, 1965, 1967; Silva Lee,1974;

Claro et al., 1990; Carter et al., 1994).

Gymnothorax; overall, mean prey size was 15% of the

Nassau grouper FL (Silva Lee, 1974).

Four studies provide a feeding profile of the Nassau

grouper (Table 5). Fish predominated, with scarids and

labrids most commonly identified, possibly because the

former can be readily recognized from stomach contents by their unique dentition (Randall, 1965). Crabs

were the most common invertebrates. Although hermit

crabs and the operculae of Strombus and Fasciolaria were

found, stomachs did not contain shells. In one Cuban

study, the most abundant items (by weight) were grunts,

parrotfishes, and octopus with a suggestion that more

grunts were taken in winter months (Claro et al., 1990).

In Belize, the predominant food, by percentage frequency of occurrence, was fish, with a high percentage

of crustaceans, especially crabs, and a small number of

gastropods, cephalopods, and pelecypods. The principal prey fish families were grunts and snappers (Carter

et al., 1994).

Like other groupers, Nassaus follow and feed with

predators, such as triggerfish, octopus, or eel (Carter et

al., 1994; Sullivan and de Garine-Wichatitsky, 1994; Rob-
28 NOAA Technical Report 146

Table 5

Principal categories of food items encountered in the stomachs of Nassau grouper, Epinephelus striatus, in four studies: (A) Virgin Islands (Randall, 1965, percent by volume);

(B) Cuba (Silva Lee, 1974, percent frequency occurrence);

(C) Cuba (Claro et al., 1990, percent by weight); (D) Belize

(Carter et al., 1994, percent frequency occurrence).

Food category A B C D

Nekton, fish 53 39 71 58

Benthic, crustaceans

crabs 23 29 8 16

stomatopods 6 3 <1 1

shrimp/prawn 5 8 <1 3

spiny lobster 4 6 4 6

hermit crab 1 <1 — 1

isopod <1 <1 — —

unidentified 1 4 — 3

Nekton, molluscs

cephalopods 5 9 15 6

Benthic, molluscs

gastropods 2 2 2 1

Unidentified — — — 5

erts et al., 1995; Sadovy, personal observ.) presumably

benefiting from spoils made available directly, or from

disturbance of prey species.

Although adult Nassaus are unspecialized predators,

early life-history phases exhibit a high degree of trophic

plasticity with evidence of filter feeding, particulate feeding, and piscivory (Grover, 1993, 1994). Pelagic-phase

Nassau grouper feed on pteropods, amphipods, and

copepods, especially Corycaeus spp., which comprised

approximately 40% of identifiable items found in one

study (Greenwood, 1991; Grover et al., 1998). Pelagic

early-juvenile Nassau grouper (20.2–27.2 mm SL) take

food items ranging from dinoflagellates (±99% by number) to fish larvae and mysids (28–79% by volume).

Epinephelus itajara Although predation on relatively

slow-moving fishes and invertebrates indicates that the

jewfish’s large size and sluggish nature typically define

its prey selection, it is able to accelerate from a resting

position with explosive speed (Bullock and Smith, 1991).

Poor development of canine teeth in this species is a

reflection of its crustacean diet, although the jewfish

does take fish bait (Smith, 1971).

Crustaceans, particularly spiny and slipper lobster and

crab, form an important part of the diet of jewfish

(Longley and Hildebrand, 1941; Randall, 1983) although fishes and hawksbill turtles have also been found

in stomachs (Randall, 1983). Juveniles consume shrimp

(including pink shrimp, Penaeus duorarum), xanthid

crab, Rhithropanopeus harrisii, and sea catfish, Arius felis

23 Erdman, Don. 1989. 890 NE 90th Avenue, Portland, OR 97220.

Personal commun.

(Odum, 1971; Bullock and Smith, 1991). Randall (1967)

analyzed the stomach contents of nine fish (1,250–1,650

mm SL) and found 69% (by volume) of the diet consisted of lobsters (Panulirus argus and Scyllarides

aequinoctialis), while fish (Dasyatis americana and Diodon

sp.), crabs, and sea turtles made up 13%, 12%, and 6%

of the diet, respectively. Fish taken in Puerto Rico contained the crab, Carpilius carallinus, Spanish and spiny

lobsters, Diodon spp., and stingrays (Erdman23).

Jewfish stomach contents from the eastern Gulf of

Mexico included the following: octopus mouthparts;

gastropod, Fasciolaria tulipa; lobsters, Panulirus argus,

Scyllarides sp.; crabs, Calappa flammea, Menippe mercenaria,

Ovalipes floridanus, Callinectes sp., Hepatus sp.; and fishes,

Chaetodipterus faber, Lactophrys quadricornis, Etrumeus teres,

and Chilomycterus schoepfi (Bullock and Smith, 1991).

3.43 Growth rate

Epinephelus striatus Growth in Nassau grouper has been

examined by size-frequency analyses, tagging studies,

field observations, and by sagittal otoliths. Most studies

indicate rapid growth, about 10 mm/month for small

juveniles, until sexual maturity at about 4–6 years, slowing to about 2mm/month, or less, in larger or sexually

mature fish (Fig. 16).

Mean monthly growth of Nassau juveniles on artificial and natural reefs in the Virgin Islands was 8.4 to

11.7 mm/month (determined during six visual censuses

over 11 months) for juveniles 30–270 mm TL (Beets and

Hixon, 1994). Similarly, juveniles sampled at Lee Stocking Island in the Bahamas grew at about 10 mm/month

between 32 and 85 mm TL (Eggleston, 1995).

The growth zones deposited in otoliths were validated

as annual using oxytetracycline (OTC) marking techniques; otolith legibility was approximately 80–95%

(Bush et al., 1996). Marginal increment analysis of the

sagittal otoliths also suggested that growth zones were

formed annually and that annual increment deposition

occurred from April to May (Claro et al., 1990).

Data from scales and otoliths indicate that fish reach

400–450 mm SL (i.e. sexual maturity) in approximately

4–7 years. However, estimates of size-at-age derived from

length-frequency data suggest more rapid growth (Olsen

and LaPlace, 1979) (Table 6). This apparent discrepancy between otolith- and length-based methods of age

determination could result from the unavailability of age

class 1 individuals in the fishery, resulting in older (i.e.

age 2+ years) individuals designated as age 1 year. Von

Bertalanffy growth parameters derived for the Nassau

grouper with the Brody growth coefficient (K) range

from 0.063–0.185 (Table 7).
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 29

Table 7

Von Bertalanffy growth equation parameters for Nassau grouper, Epinephelus striatus. Standard equation for length-at-age

is: Lt=L∞(1–e–k(t–t0)). Lengths are in cm (length type indicated).

Parameter

Source & method Locality Length type L∞ t0 K

Olsen & LaPlace, 1979 Virgin Islands SL 97.4 0.4881 0.185

Claro et al., 1990 Cuba (SW) TL 94.0 –3.27 0.063

Cuba (NE) 76.0 –1.122 0.127

Thompson & Munro, 1978 Jamaica TL 90.03 — 0.090

Baisre & Páez, 1981 Cuba — 92.8 — 0.100

1 Appears also as to = –0.488 in some places.

2 Appears also as –4.13 in Abstract.

3 L∞ assumed, based on tagging data from Randall, 1962, 1963.

Table 6

Epinephelus striatus size-at-age data for ages 1-13 years. All lengths are in mm (standard/SL or total/TL lengths as indicated). Ageing method is given.

Age (years)

Source 1 2 3 4 5 6 7 8 9 10 11 12 13

a 293 354 390 464 537 561 634 659 — — — — —

b 160 270 — 410 480 540 570 600 640 650 660 700 710

c 175 253 309 358 401 436 468 497 519 542 563 580 591

d 174 254 315 366 414 451 483 518 559 583 594 617 —

e 235 370 435 500 543 605 660 720 760 800 — — —

a: Buesa, 1987; Cuba, aged by scales/TL.

b: Bush et al., in press; Cayman Islands, aged by otoliths/TL lengths estimated from observed growth curve.

c & d: Claro et al., 1990; SW and NE Cuba, respectively, fish from both areas were aged by otoliths and backcalculation/TL.

e: Olsen and LaPlace, 1979; Jamaica, aged by length-frequency data/SL.

Growth rates were also determined by field observations and tagging studies. In the Virgin Islands, animals

tagged for less than 300 days yielded the following

growth rates: 175–250 mm TL grew about 4.55 mm/

month; 251–325 mm TL about 3.5 mm/month; 326–

451 mm TL about 1.92 mm/month (Table 8) (Randall,

1962). However, growth rates were evidently underestimated because of growth suppression due to tagging

(Thompson and Munro, 1978). Fish that remained in

the field for 313 to 737 days had higher growth rates,

varying from 4 to 6.6 mm/month for fish in the 256–

380 mm TL size. Growth in Nassau grouper was also

measured by calculating weight increments of marked

fish in the field: weight increase for 7 individuals in the

700 g size class was 20–50% per year with an average of

38% (Bardach and Menzel, 1957). Data suggested a

decline in growth rate after jaw tags were applied.

Length-weight relationships for standard (Fig. 17),

total, and fork lengths, and TL-SL relationships are

shown in Table 9.

Epinephelus itajara Age in jewfish ranging in size from

100 to 2,200 mm TL was determined from sectioned

otoliths (sagittae); fish attained a maximum of 37 years,

assuming that temporal validation of growth zones applies equally to all age classes. For ages 1–10 years,

opaque zones in sectioned sagittae form annually between April and August, as determined by both marginal

increment analyses and OTC marking of two individuals, ages 3 and 4 years, maintained in captivity for 11

and 22 months, respectively (Bullock et al., 1992).

Otolith legibility was almost 100%.

Fish grew slowly after age 7 years (Bullock et al., 1992).

Average annual growth through age 6 was greater than
30 NOAA Technical Report 146

Figure 17

Length-weight relationship of the Nassau grouper,

Epinephelus striatus, captured in the Bahamas between

1988 and 1990; Log Ungutted Weight (g) = –4.67 + 3.03

Log Standard Length (mm); n=186; r2=0.97; p<0.001

(Sadovy and Colin, 1995, and unpublished data).

Table 8

Growth of tagged-recaptured Epinephelus striatus in the

Virgin Islands (from Randall 1962, 1963). Lengths are

total lengths in mm.

Length at Length at Tagging Growth per

tagging recovery period month/mm

175 180 78 1.95

195 264 513 4.08

196 200 70 1.74

198 207 47 5.82

204 252 273 5.33

204 220 55 8.96

213 230 134 3.87

230 241 38 8.80

232 256 168 4.35

237 238 44 0.67

246 255 78 3.51

250 297 257 5.56

252 252 33 0.00

254 317 288 6.64

255 295 509 2.39

276 280 104 1.17

280 286 49 3.72

292 301 108 2.54

295 330 136 7.84

298 304 92 1.98

299 304 39 3.91

302 322 103 5.90

302 332 161 5.67

307 314 80 2.56

309 366 52 3.33

314 311 39 0.00

314 321 106 2.01

314 355 215 5.78

316 322 102 1.78

320 324 80 1.52

325 327 78 0.75

330 333 42 2.17

340 341 42 0.72

343 348 177 0.86

357 365 127 1.91

358 365 49 4.34

364 372 105 2.32

378 382 62 1.96

410 413 55 1.66

451 455 70 1.74

225 266 313 4.00

229 334 737 4.40

240 338 661 4.40

245 333 674 4.40

250 380 667 5.80

100 mm/year, declining to about 30 mm/year by age

15, and to less than 10 mm/year after age 25 (Fig. 18).

Von Bertalanffy growth parameters calculated for the

jewfish, both males and females combined, yielded

K = 0.13/year, L∞ = 2,006 mm TL and to = -0.49 years.

There was no significant difference between the sexes

in growth parameters (Bullock et al., 1992).

Length-weight relationships for standard (Fig. 19),

total, and fork lengths, and TL-SL relationships are

shown in Table 9.

3.5 Behavior

3.51 Migrations and local movements

Epinephelus striatus Nassau grouper are solitary and,

while they remain in specific areas for extended periods (Bardach, 1958), they may exhibit distinct ontogenetic movements, especially as juveniles (Section 2.1).

Over 12 months, in one area, there was a gradual turnover of individuals until the original population had

been replaced (Bardach, 1958). They are able to home

to residential reefs over short distances based on visual
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 31

Table 9

Length-weight and length-length parameters for Epinephelus striatus and E. itajara. The length-weight relationship is defined as: W=aLb, where L is length (standard/SL, fork/FL or total/TL, as indicated) in mm and W is body weight in grams

(gutted, G, or ungutted, UG, as indicated—where known). The standard length-total length relationship is defined as:

TL=a+bSL.

Parameter

Locality Restrictions1 a b Source

Length-weight

Epinephelus striatus

Virgin Islands 180-760 (SL) 0.0097 3.23 Olsen and LaPlace, 1979

n=241

(St. Thomas/St. John) 330-770 (SL) 1.43 × 10–6 3.38 Bohnsack and Harper, 1988 (UG)

n=73

Puerto Rico 210-645 (FL) 1.26 × 10–5 3.04 Bohnsack and Harper, 1988 (UG)

n=60

Cuba (NE) n=75 (TL) 0.1980 2.98 Claro et al., 1990

Cuba (SW) n=270 (TL) 0.0052 3.30 Claro et al., 1990

Jamaica 325-825 (TL) 0.0107 3.11 Thompson and Munro, 1978 (UG)

n=112

Belize 180-802 (SL) 0.0107 3.08 Carter et al., 1994 (UG implied)

n=930

Florida 203-516 (TL) 3.8 × 10–6 3.23 Bohnsack and Harper, 1988 (UG)

n=9

Bahamas 174-724 (SL) 2.14 × 10–5 3.03 Sadovy and Colin, 1995 (UG)

Epinephelus itajara

Gulf of Mexico 75-2160 (TL) 2.94 × 10–5 2.94 Bullock et al., 1992 (G)

n=402 (TL)

Gulf of Mexico n=66 (TL) 3.056 × 10–8 1.31 Bullock et al., 1992 (UG)

Total length-standard length

Epinephelus striatus

Cuba n=330 2.24 1.11 Claro et al., 1990

Jamaica 430-750 3.00 1.09 Thompson and Munro, 1978

n=26

Bahamas 174-695 2.81 1.13 Sadovy and Colin, 1995

n=33

Epinephelus itajara

Gulf of Mexico — 32.45 1.18 Lew Bullock, text footnote 9

1 Restrictions are upper and lower sizes in samples analyzed.

cues; blinded fish do not home (Bardach, 1958). Ten

recaptures, out of 11 fish originally tagged in Bermuda,

demonstrated homing between isolated patch reefs separated by 100 m of sandy substrate. The greatest distance

traveled was 16 km in 12 days (Randall, 1962, 1963). In

the Florida Keys and the Virgin Islands, tagged, translocated fish exhibited strong home-reef specificity

(Beaumariage and Bullock, 1976; Beets and Hixon,

1994). Twenty-seven tagged, 31-month old fish (310–380

mm TL), which had been raised from eggs in captivity,

survived at least 200 days in the field with one fish moving 12 km in eight days (Roberts et al., 1995). In the

Bahamas, juveniles moved from inshore areas offshore

to natural and artificial reefs within a year of settlement

out of the plankton (Eggleston, 1995).

Nassau groupers are diurnal or crepuscular in their

movements (Collette and Talbot, 1972) and do not usually move far from cover (Starck and Davis, 1966). Three

sonically tagged fish were most active in the hours prior

to and following sunrise and sunset; two of the fish

moved randomly within a 160 m × 80 m rectangle during the day, returning in the evening to where they had

initiated daily activities (Carter et al., 1994). Sullivan and

de Garine-Wichatitsky (1994) estimated that individu-
32 NOAA Technical Report 146

als moved at least 400 m/day and 20 m or more from

their home reefs.

Figure 18

Observed ages (years), total lengths (mm), and predicted growth model for jewfish, Epinephelus itajara, collected from the eastern Gulf of Mexico (n=382) (from

Bullock et al., 1992).

Figure 19

Length-weight (gutted) relationship of the jewfish, Epinephelus itajara, captured in the eastern Gulf of Mexico (from Bullock and Smith, 1991).

Movement away from resident reefs occurs as spawning time approaches and distances traveled to an aggregation site can be substantial. Observations of migrating groups of fish (“corridas”), on or before the full

moon of spawning, indicate that at least some fish travel

to aggregation sites in groups ranging from a few fish

up to about 500 individuals (Colin, 1992) (see also Section 3.16). Several dozen fish were observed passing

slowly along the 30–40 m shelf break contour at several

localities along a reef in Belize in late October and early

November (Carter et al., 1994), i.e. a month or two before spawning was likely. One tagged fish moved at least

110 km in two months to an aggregation site in the Bahamas (Colin, 1992). Another fish, tagged on an aggregation site in Belize, was recaptured 2 years later 240

km north of the tagging site (Carter et al., 1994).

Observations suggest that individuals can return to

their original home reef following spawning; several

large adult Nassaus in the Bahamas, clearly swollen with

gametes, disappeared from residential areas for periods

ranging from 10 days before, to a few days after, the full

moon of December 1989. The same fish returned visibly slimmer. They remained in home areas for the January 1990 full moon and were seen neither to swell with

gametes nor to exhibit courtship behavior, suggesting that

not all mature fish aggregate in every aggregation month

in each reproductive season (Colin21).

In Honduras, groupers normally located 48 km from an aggregation site

disappeared from resident reefs at

spawning time (Fine, 1992).

Epinephelus itajara Jewfish apparently stay within circumscribed areas

for up to one year (Smith, 1976) with

large individuals found both inshore

and offshore. During the spawning

season, jewfish aggregate at specific

locations, although it is not known

what distance is traveled to reach aggregation sites. Of 217 adult jewfish

tagged at spawning sites in southwest

Florida in 1996–97, 5 were re-sighted

although fish tagged on one trip were

not observed at the same site on the

next trip. One fish tagged at one aggregation site was sighted at another,

6 km away, on the next day. Outside

of aggregations, jewfish showed strong

site fidelity (Koenig et al.18).

3.53 Responses to stimuli

Epinephelus striatus Little is known

of responses to stimuli in the Nassau
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 33

grouper, with the exceptions of responses related to

crowding, sound generation, reproduction, and cleaning behavior. This species is noted for a negative

rheotropic response when confined and crowded; heads

are oriented away from flowing water, possibly to protect the lips which are the most sensitive integumentary

region (Jordan, 1917). Although this species tends to

be solitary, individuals will crowd peaceably in caves

(Silva Lee, 1974) or in fish traps (Sadovy, personal

observ.), with some proclivity to re-enter fish traps resulting in multiple recaptures (Randall, 1962).

The Nassau grouper produces a loud grunting sound

which can be heard with the unaided ear. The sound is

produced by contraction of bilateral muscles in the region directly behind the opercles and around the air

bladder (Moulton, 1958). In aquaria, they emit deep

booms and sustained rumbles as single grunts or in rapid

series (Fish and Mowbray, 1970). In the field, occasional

grunts or “plop” sounds are produced in response to

specific stimuli, such as being disturbed by divers

(Hazlett and Winn, 1962; Fish and Mowbray, 1970;

Bright, 1972; Nagelkerken, 1981). Acoustical characteristics of the sounds range from <85 cps to about 2,000

cps, with sound duration varying from 51.0 to 124.0 ms

(Hazlett and Winn, 1962). Nassaus responded to irregularly pulsed signals designed to attract sharks, off the

Bahamas, approaching the sound source slowly and

moving away 10–30 seconds later (Myrberg et al., 1969).

Nassau grouper are frequently involved in symbiotic

cleaning behavior at cleaning stations on coral reefs;

species that clean them include several gobies, Gobiosoma

spp., and shrimp that remove gnathiid isopods from the

body, fins, gill chambers, and mouth (Collette and Talbot, 1972; Böhlke and McCosker, 1973; Darcy et al., 1974;

Sargent and Wagenbach, 1975; Sullivan and de GarineWichatitsky, 1994). Interestingly, naive Nassau grouper

raised in captivity in the absence of cleaners, allowed

cleaning by Gobiosoma evelynae and by Stenopus hispidus

and Periclimenes spp. within one hour of release onto a

coral reef (Roberts et al., 1995). Movements and activity patterns of Nassaus were significantly influenced by

the position of cleaning stations in the Bahamas (Sluka

and Sullivan, 1996; Sluka et al., 1997a).

Epinephelus itajara Little is known of jewfish responses

to stimuli although they often produce sounds, submit

to cleaning behavior, and may approach divers. One

large individual made a tremendous boom, sometimes

followed by two smaller grunts, whenever prodded; two

large fish made no spontaneous grunts but emitted several loud bursts when pursued by a diver (Fish and

Mowbray, 1970). The swimbladder and associated muscles

are believed to provide the sound-producing mechanism

(Fish and Mowbray, 1970). Sonic activity is associated with

courtship behavior; during an August full moon period at

a wreck off the Florida coast, a presumed male approached

presumed females and boomed several times (Colin, 1994).

Cleaning gobies were observed removing parasites from

the mouth of a jewfish in Puerto Rico (Mandojana, 1983).

Large jewfish have been reported to approach divers closely

(Zinkowski, 1971) and are not wary, making them highly

susceptible to spearfishing.

4 POPULATION

4.1 Structure

4.11 Sex ratio

Epinephelus striatus The sex ratios of adult Nassau grouper in relatively undisturbed populations seldom differ

markedly from unity. However, there are generally more

females than males at exploited spawning sites compared

to unexploited sites, suggesting that sex-selective fishing may occur during either aggregation or non-aggregation periods (Table 10) (Carter et al., 1994; Sadovy

and Colin, 1995). The most biased adult sex ratio reported is 4:1 (F:M) in heavily exploited areas in Cuba,

although the authors stated that if all “intersexes” (term

not defined) had been counted as males, the sex ratio

would be 1:1 (Claro et al., 1990). Given the bisexual

juveniles found in this species, sex assignment of young

fish could well have been in error, greatly overestimating female numbers (Section 3.11).

Care is needed in assessing sex ratios at aggregations,

however, because of possible gear selectivity, differences

between the sexes in time spent at aggregation sites, or

migration patterns. For example, in Bermuda in early

July, only 20% of individuals moving towards the aggregation site were females, but by late July the proportion

of females had risen to 36%; either males precede the

females to spawning sites, or females do not enter fish

traps until the onset of spawning, as some fishers believe (Bardach et al., 1958).

Epinephelus itajara The only information on sex ratios

is a finding of 1.75:1 (F:M) in the eastern Gulf of Mexico,

from samples taken periodically from commercial and

recreational catches between 1977 and 1990 (Bullock

et al., 1992).

4.12 Age composition

Epinephelus striatus Nassau grouper attain 29 years with

sexual maturation occurring at 4 years or above; fish

taken commercially generally fall within age classes 2–9

years and include many immature individuals; no age

differences at size between males and females were noted

(Bush et al., 1996) (Section 5.42) (Table 3). Over 80%
34 NOAA Technical Report 146

of the samples from an aggregation in the Virgin Islands

were aged 4–6 years (as estimated by probit analysis)

(Olsen and LaPlace, 1979), while most fish taken at the

aggregations in the Cayman Islands were aged 7–8 years

(Fig. 20). Age classes 6–9 dominated in southwestern

Cuba and 3–8 years in northeastern Cuba (Claro et al.,

1990).

Epinephelus itajara In samples taken from the eastern

Gulf of Mexico, male and female age at size overlapped

Table 10

Mean sizes and sex ratios of aggregating and non-aggregating Nassau grouper, Epinephelus striatus, in the western Atlantic,

from lightly (top of table) to heavily (bottom of table) exploited areas. Fishing intensity implied by descriptions of current

and historic fishing activity (from Sadovy and Colin, 1995). Number in parentheses refers to references.

Mean SL in mm

Sex ratio Max SL Gear

F:M F M in mm used1 Location and source2

0.57:1(n=750) 526 529 750 T,H Bermuda, offshore banks > 60 m deep (1)

0.72:1(n=163) 5543 718 H,T Jamaica, offshore (3)

1.5:1(n=694) 517 521 802 H,S Belize, aggregation (4)

2.0:1(n=42) 502 487 568 G Mexico, aggregation (2)

0.67:1(n=70) 514 5034 657 G Mexico, aggregation (2)

1.0:1(n=940) 589 585 940 T,H U.S.V.I., aggregation (5)

1.9:1(n=95) 516 512 640 H Caymans, aggregation (6)

2.0:1(n=140) 506 538 772 H Caymans, aggregation (7)

2.2:1(n=717) 418 420 760 H,S Belize, nonaggregated(4)

2.4:1(n=485) 418 420 690 H,S Belize, aggregation (4)

2.5:1(n=216) 549 5174 700 T Bahamas, aggregation (8)

4.0:1(n=319) >5003 710 S,T Cuba, (9) (only adults assessed)

1 Gear used: T=trap; H=handline; S=spear; G=gillnet.

2 Sources: (1) Bardach et al., 1958; (2) Sosa-Cordero & Cárdenas-Vidal ,1997; Aguilar-Perera, 1994; (3) Thompson & Munro, 1978; (4) Carter

et al., 1994; (5) Olsen and LaPlace, 1979; (6) Colin et al., 1987; (7) Bush (text footnote 42); (8) Colin, 1992; (9) Claro et al., 1990. 3 Males and females combined.

4 Females significantly larger than males at p<0.05, otherwise no sex difference in size.

Figure 20

Age frequency distribution of Nassau grouper, Epinephelus striatus, caught at 5 aggregations

off the Cayman Islands from 1987 to 1992 (Bush et al., in press; with permission).
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 35

and the majority of individuals were between 9 and 15

years. Few fish exceeded 30 years (Bullock et al., 1992).

4.13 Size composition

Epinephelus striatus A maximum length of 1,220 mm

TL and weight of 23–27 kg are recorded for the Nassau

grouper (Evermann, 1900; Randall, 1963; Smith, 1971;

Buesa, 1987). Most fish at markets, however, are considerably smaller (i.e. 2–11 kg). Weights of aggregating fish

ranged from 5–12 kg, with a maximum of 14 kg (Böhlke

and Chaplin, 1968; Smith, 1971, 1978; Aguilar-Perera,

1994). Grouper up to 960 mm SL were taken in the Virgin Islands although fish larger than about 700 mm were

Figure 21

Length-frequency distributions of male and female Nassau grouper, Epinephelus

striatus, taken from aggregations [males = white bars, females = black bars] in Belize:

(A) unexploited site (n=694); (B) exploited site (n=485) (Carter et al., 1994).

uncommon (Olsen and LaPlace, 1979). Maximum theoretical mean length (L∞ from the von Bertalanffy growth

function–von Bertalanffy, 1957) has been estimated at

between 760–1,129 mm TL (Thompson and Munro,

1978; Olsen and LaPlace, 1979; Claro et al., 1990).

Mean male and female sizes are similar within a given

area, or at a specific aggregation site, with some indication that sizes of both sexes decline in areas of higher

exploitation within a specific region (Table 10). When

exploitation is high, catches are largely comprised of

juveniles. For example, in Belize, the average length of

both sexes was 100 mm smaller in catches from exploited

compared to unexploited aggregations (Fig. 21). In only

two cases were females significantly longer than males,
36 NOAA Technical Report 146

Figure 22

Length-frequency distribution of Nassau grouper, Epinephelus striatus, from commercial fishery landings in Puerto Rico between 1986 and 1990. Light stipple=immature;

dark stipple=mature. Source: Puerto Rico Fisheries Research Laboratory, Department of Natural Resources, State/Federal Fishery Program.

24 SAFMC. 1983. Fishery Management Plan, Regulatory Impact Review, and Final Environmental Impact Statement for the Snapper

Grouper Fishery of the South Atlantic Region, 173 p.

while males were never larger than females (Thompson

and Munro, 1978; Sadovy and Colin, 1995). In heavily exploited areas of Puerto Rico, Florida (Figs. 22 and 23) and

Cuba (Espinosa, 1980), most catches consisted of juveniles.

Individuals tend to be smaller inshore (more heavily

exploited areas) than offshore (less exploited areas). In

Bermuda and Jamaica (Figs. 24 and 25), and off the U.S.

Atlantic coast, smaller Nassaus are found on shallow

reefs, with larger individuals on deep reefs (SAFMC24).

Epinephelus itajara The maximum length for jewfish

ranges from 2,000–2,500 mm TL (Heemstra and

Randall, 1993) with a maximum weight of 320 kg (Smith,

1971). Individuals of more than 225 kg have been commonly reported throughout the jewfish’s range and the

International Game Fish Association all-tackle record

(as of 1990) is 308.44 kg (Heemstra, 1991). Male and

female size ranges overlapped in the eastern Gulf of

Mexico (Bullock et al., 1992). Of 481 fish sampled,

mainly by speargun and handline, sizes ranged from

795–2,057 mm TL for males, 338–2,155 for females, and

75–2,160 for fish of undetermined sex (Bullock et al.,

1992).

The great majority of jewfish taken commercially are

immature (i.e. <1,200 mm TL). All 30 reported individuals caught in Puerto Rico between 1983 and 1993

were immature (i.e. less than 875 mm TL) (Caribbean

Fishery Management Council [CFMC]25). Between 1979

and 1987, the size range of jewfish from the U. S. Marine Recreational Fishery Statistical Survey intercept

samples (n=21 fish) was between 250–1,570 mm TL, most

less than 1,000 mm TL (GMFMC9).

4.2 Abundance and density

Epinephelus striatus The Nassau grouper was formerly

one of the most common and important commercial

groupers in the insular tropical western Atlantic and

Caribbean (Smith, 1978; Randall, 1983; Appeldoorn et

al., 1987; Sadovy, 1997). Declines in landings, catch per

unit of effort (CPUE), and, by implication, abundance,

have been reported throughout its range and it is now

considered to be commercially extinct in a number of

areas. Information on past and present abundance and

density is based on a combination of anecdotal accounts,

25 Caribbean Fishery Management Council (CFMC). 1993. Amendment 2 to the Fishery Management Plan for the Shallow-water Reef

Fish Fishery of Puerto Rico and the U.S. Virgin Islands, 29 p.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 37

Figure 23

Length-frequency distributions of Nassau grouper, Epinephelus striatus, from recreational fishery landings between 1976 and 1985 in Biscayne National Park, Dade

County, Florida (from Bohnsack, text footnote 31) (light stipple = immature; dark

stipple = mature).

26 CFMC. 1985. Fishery Management Plan, Final Environmental Impact

Statement, and Draft Regulatory Impact Review, for the Shallow-water

Reef Fish Fishery of Puerto Rico and the U.S. Virgin Islands, 104 p.

27 Bohnsack, J. A., D. L. Sutherland, A. Brown, D. E. Harper, and D.

B. McClellan. 1986. An analysis of the Caribbean biostatistical database for 1985. Coast. Res. Dev. Rep. Carib. Fish. Mgt. Coun. Contr.

No. CRD-86/87-10, 35 p.

28 Beets, Jim. 1990. Division of Science and Mathematics, Jacksonville University, 2800 University Blvd North Jacksonville, FL 32211.

Personal commun.

visual census surveys and fisheries data (see also Section 5.43).

Heavy fishing, especially of spawning aggregations, and

certain fishing practices such as spearfishing and the excessive capture of juveniles in small-mesh fish traps, are

almost certainly to blame for severe declines. With reports

of illegal capture in the Atlantic and Caribbean, and legal

capture continuing in other areas (e.g. U.S.V.I. territorial

waters), an increase in Nassau grouper numbers is unlikely

because the status of Nassau grouper has not changed

noticeably since the ban on fishing for them in Caribbean

and Atlantic waters was implemented (Section 6).

During the first U.S. survey of the fishery resources of

Puerto Rico, the Nassau grouper was noted as a common and very important food fish, reaching a weight of

50 lbs (22.7 kg) or more (Evermann, 1900). By 1970,

Nassau grouper was still the fourth most common shallow-water species landed in Puerto Rico (Thompson,

1978) and dominated the reef fish fishery of the Virgin

Islands, where an aggregation in the 1970s contained

an estimated 2,000–3,000 individuals (Olsen and

LaPlace, 1979; CFMC25, 26). By 1981, however, the Nassau

grouper had almost completely disappeared from

catches in the U.S. Caribbean (CFMC26) and by 1986

was considered commercially extinct in the U. S. Virgin

Islands/Puerto Rico region (Bohnsack et al.27). Only about

1,000 kg were landed during the latter half of the 1980s in

Puerto Rico, most of them sexually immature (Sadovy,

1997).

Although management measures went into effect in

the U. S. Caribbean in 1985, Nassau grouper numbers

are not increasing, probably because illegal fishing persists (Beets28). Catches have plummeted in other areas

where this species was once common, notably in Jamaica

and possibly the Dominican Republic (Sadovy, 1997)

(Section 5.43).

This species was once abundant in the Lesser and Greater

Antilles. However, interviews with fishers, visual surveys, and

analysis of commercial catches indicate that the Nassau

grouper is no longer common in the Netherlands Antilles,

probably as a result of intensive spearfishing during the
38 NOAA Technical Report 146

Figure 24

Length distributions of Nassau grouper, Epinephelus

striatus, in Bermuda from (A) inshore and (B) offshore

areas (from Bardach et al., 1958).

1960s and 1970s (Nagelkerken, 1982). Similarly, on the

insular platform of Martinique, this species was clearly more

abundant prior to the introduction of arrowhead fish traps,

according to interviews with fishers (Gobert, 1994). Underwater visual censuses in St. Lucia, Jamaica, and the

Dominican Republic produced no records of Nassau grouper (Roberts29, Schmitt and Sullivan30) (Table 11).

In the western Atlantic, Nassau grouper have declined

sharply in density, number, and average weight since

29 Roberts, Callum. 1994. University of York, York Y01 5DD, UK. Personal commun.

30 Schmitt, E. F., and K. M. Sullivan. 1994. Research applications of

volunteer generated coral reef fish surveys. The Nature Conservancy and the University of Miami, Department of Biology Report.

Coral Gables, Florida. 38 p.

1975 (Bannerot et al., 1987). Density in Bermuda in the

1950s was estimated at 12 fish per acre (0.405 hectare),

with the fish weighing an average of 1.1 kg (Bardach and

Menzel, 1957); density and landings declined drastically

between 1975 and 1981 (Luckhurst, 1996) such that the

species is now considered commercially extinct (Sadovy,

1997).

Although there are few data on historic abundance

of Nassaus off the U. S. mainland, it appears that abundance was once high in southern Florida (Springer and

McErlean, 1962; Bohnsack31). Anecdotal reports from

spearfishers noted large daily catches of Nassau in the

1950s (Bohnsack31). Starck (1968) reported Nassau

grouper frequently at Alligator Reef in the Florida Keys.

Recent interviews of Florida Keys’ residents suggested

that Nassaus were once caught in much greater numbers from the upper Florida Keys and the Bahamas. Reef

fish surveys by the NMFS Southeast Fisheries Science

Center’s (SEFSC) Reef Team revealed low and declining densities from 1979–94 in southern Florida; of 3,518

visual point counts Nassau grouper were recorded 29

times, the number declining to zero in 1993 (Figs. 26A

and B) (for census method, see Bohnsack and Bannerot,

1986). In the Dry Tortugas, where Nassaus were once

abundant, only one individual was recorded in 1994 out

of 183 point censuses and none in 37 predator censuses.

On Elbow Reef, Florida Keys, mean Nassau densities were

0.01–0.04 fish per 100 m2 in 1993–94 (Sluka et al., 1998),

with few seen on census dives through the Florida Keys

(Table 11). Censuses comparing areas protected and unprotected from fishing indicate that Nassau grouper, where

protected, have a higher density and were one of the dominant grouper species observed (Sluka et al., 1994).

Most alarming, however, have been declines in numbers of Nassau grouper aggregating to reproduce at

spawning sites (Sadovy, 1993, 1997). In many locations,

aggregations are heavily targeted and between about one

quarter and one half of all known aggregations no longer

form at traditional sites (Section 5.43). The impact of

aggregation losses on reproductive output and population abundances is not known, but is likely to be substantial. For example, in both Bermuda and Puerto Rico,

where traditionally fished aggregations no longer form,

local stocks are considered to be commercially extinct.

Population abundances are expected to be largely dependent on the supply of recruits from healthy spawning aggregations.

Epinephelus itajara The decline in inshore jewfish

populations began in the 1950s or 1960s, undoubtedly

31 Bohnsack, J. A. 1990. Black and Nassau grouper fishery trends.

Appendix in South Atlantic Reeffish Plan Development Team Report of the Snapper-Grouper Assessment of the South Atlantic Fishery Management Council, 18 p.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 39

Figure 25

Length distributions of Nassau grouper, Epinephelus striatus, in Jamaica from inshore

exploited areas (darkly shaded) (n=20) and offshore unexploited (lightly shaded)

areas (n=163) (from Thompson and Munro, 1978).

Table 11

Number and percentage of dives at each location in the Florida Keys and the Caribbean where Nassau grouper and jewfish

were observed during volunteer censuses conducted by R.E.E.F., the Reef Environmental Education Foundation. All censuses were conducted in 1994. Data from Schmitt and Sullivan (text footnote 30).

Percent of Percent of

Dives with Dives with dives with Dives with Dives with dives with

Location Number of Minutes of one Nassau 2-10 Nassau Nassau one jewfish 2-10 jewfish jewfish

dives bottom time observed observed observed observed observed observed

Key Largo 145 10,449 14 5 13 0 0 0

Marquesas Keys 18 1,307 3 1 22 0 0 0

Key West 158 9,910 5 0 4 0 0 0

Dry Tortugas 204 11,517 13 5 9 2 0 1

Dominican Republic 70 4,165 0 0 0 0 0 0

a consequence of intensive fishing of aggregations and

spearfishing of adults which are unwary of divers. Once

common in Florida and parts of the Gulf of Mexico, the

jewfish is rarely seen nowadays in these areas or, indeed,

elsewhere in the West Indies (Randall, 1983). It is uncommon in the Netherlands Antilles following depletion by spearfishing (Nagelkerken, 1981). Although the

historical center of abundance was peninsular Florida,

the fishery there closed in 1990 due to rapid declines in

catch and CPUE (Section 5.43) and in the mid-1990s,

individuals were rarely seen. For example, one diver in

Palm Beach County who dives approximately 100–150

times a year has seen but one jewfish since 1990 and

noted that where an aggregation of jewfish once formed

19 km offshore from Vero Beach in 22–24 m of water,

only 1 or 2 fish were observed in recent years. Whereas

video footage of aggregations off Palm Beach and Jupiter, Florida, in 1959 and in 1969 shows groups of several

dozen jewfish in shallow reef areas (Parks32), no aggre32 Parks, William. 1992. 919 S.W. 27th Place, Boynton Beach, FL

33435. Personal commun.
40 NOAA Technical Report 146

Figure 26

Number of Nassau grouper, Epinephelus striatus, observed

from Biscayne National Park to the Dry Tortugas in the

Florida Keys: (A) per sample of 5 minute visual point

censuses; and (B) per 15 minute predator count. (NMFS

Southeast Fisheries Science Center’s Reef Resources

Team).

gations have been observed off the east coast of Florida

within the last 25 years. The jewfish was reportedly common 10 to 20 years ago off Belize and is now rarely seen

(Wells33). A survey conducted in 1994 on the status of

the jewfish along the coast of Brazil showed that this

species had become rare, with a drastic decline in abundance over the previous 10 years, possibly due to illegal

spearfishing with SCUBA. Increased numbers, however,

were recently observed at Fernando de Noronha in a

marine park protected since the early 1980s (Ferreira

Padovani and Maida, 1995).

Exploitation of deep-water jewfish populations had

barely started when declines were noted. Heavy exploitation of offshore populations was initially limited by

the absence of electronic navigation equipment, al33 Wells, Sue. 1993. 56 Oxford Road, Cambridge CB4 3PW, UK. Personal commun.

34 Eklund, A. M. 1994. Status of the stocks of Nassau grouper, Epinephelus

striatus, and jewfish, Epinephelus itajara. Final Report. SEFSC report.

Miami Contribution #MIA-94/95-15, Miami, FL, 170 p.

35 SEFSC, NMFS, NOAA, 75 Virginia Beach Drive, Miami FL 33149.

Unpubl. data.

though large jewfish (170–200 kg) were taken from Louisiana oil platforms in the 1960s (Cuccia 1962, 1963).

When the LORAN-C navigation device became widely

available in the 1980s, the isolated reefs and wrecks offshore became easy to locate repeatedly and rapid declines in jewfish catches resulted (Eklund34).

The number of jewfish on each of four aggregation

sites in the eastern Gulf of Mexico declined shortly after discovery. On deep water wrecks, known aggregations of up to 100–150 jewfish declined to 0–10 fish by

1989 (DeMaria17) (Fig. 27); since early estimates of numbers in the low visibility waters were probably conservative, the decline in abundance is likely even greater than

these numbers suggest.

Visual censuses produce few jewfish sightings. There

were no observations of jewfish in any of the NMFS

SEFSC Reef Team visual point counts or predator

searches, from 1979–94, from Biscayne National Park

to the Dry Tortugas, Florida, off the Florida Keys

(SEFSC35). Jewfish were seen on only two of the 204 Reef

Environmental Education Foundation (R.E.E.F.) dives

logged in the Dry Tortugas, Florida, with none at the

other R.E.E.F. census locations (Table 11).

4.3 Natality and recruitment

4.31 Reproduction rates

Epinephelus striatus Fecundity estimates from wildcaught Nassau grouper are few and varied, but suggest

a mean relative fecundity of between 3 and 5 eggs/mg

of ripe ovary, depending on the method used, i.e. which

stages of oocytes are included in egg counts. Estimates from

Belize yielded a mean relative fecundity of 4.1 eggs/mg

ovary weight and a mean total number of oocytes (stage

unspecified) of 4,200,000 (range = 350,000–6,500,000

for females of 300–700 mm SL) (Carter et al., 1994).

Estimated number of eggs in the ripe ovary (90.7 g) of a

445 mm SL individual from Bermuda was 785,101

(Bardach et al., 1958). In the Virgin Islands, fecundity

estimates made from 42 mature females gave a mean

value of 4.97 eggs/mg of ovary (s.d.=2.32) with mean

egg production of 4,800,000 eggs (Olsen and LaPlace,

1979). However, since this latter estimate includes

previtellogenic oocytes, which may not recruit into the

vitellogenic stock prior to spawning, it is considered to

be an overestimate. Fecundity estimates were also made,

based on vitellogenic oocytes only, from Bahamas fish

(Fig. 28) producing a mean relative fecundity of 2.9/mg
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 41

Figure 27

Estimated mean number of jewfish, Epinephelus itajara, observed on wrecks in the

Gulf of Mexico in 30–50 m of water before and after fishery closure in 1990. Data

are taken from the log of Don DeMaria17.

Figure 28

Relationship between number of vitellogenic oocytes (>0.17 mm diameter) and

standard length in Nassau grouper, Epinephelus striatus, from the Bahamas. The

regression line is: No. oocytes = –5407734.1 + 110905.9 SL (r2 = 0.44; p<0.001;

n=64). Counts were taken on ovaries collected several days prior to and on the day

of the full moon in December 1988 and January 1989. [Figure prepared by Pat

Colin, Yvonne Sadovy, and Ione Hunt von Herbing as part of a project supported

by the Caribbean Marine Research Center, National Undersea Research Program,

NOAA; P. Colin–project leader].
42 NOAA Technical Report 146

ripe ovary (s.d.=1.09; n=64) and a mean fecundity of

716,664 (range = 11,724–4,327,440 for females of 475–

686 mm SL). Estimates of oocyte production from animals induced to spawn in captivity are closer to those

based solely on vitellogenic oocyte counts and are given

in Section 7. In the absence of more precise fecundity

and annual spawning frequency data, annual fecundity

should be considered to fall towards the lower end of

the above estimates.

Epinephelus itajara The only indication of egg output

comes from batch fecundity estimates made for two females. The first measured 1,322 mm SL and had a batch

fecundity of 38,922,168 ± 1,518,283 oocytes. The second measured 1,397 mm SL and had a batch fecundity

of 56,599,306 ± 1,866,130 oocytes (Bullock and Smith,

1991).

4.32 Factors affecting reproduction

Epinephelus striatus All reproductive activity is thought

to take place during brief annual spawning aggregations

of hundreds to thousands of individuals, although it is

possible that spawning may occasionally occur outside

of aggregations, on occasion (Sadovy and Colin, 1995).

Given that many of the spawning aggregations have become severely depleted and between 25–50% no longer

form, it is probable that reproductive potential for some

populations has been seriously compromised. Moreover,

observations of reproductive activity, duration of aggregations, and intensity of color changes suggest that

spawning becomes abbreviated or ceases when fish numbers are low (Section 3.16) (Colin, 1992; Aguilar-Perera

and Aguilar-Dávila, 1996). In extreme cases, such as

Bermuda, or Puerto Rico, where aggregations no longer

form, Nassau grouper are now rarely taken or observed.

The loss of juveniles in capture fisheries (Section

5.42), or through loss of critical juvenile habitat, will

almost certainly influence numbers of reproductive

adults, with potential negative impacts on reproductive

output.

Epinephelus itajara Factors affecting reproduction in

the jewfish are not known. The size of spawning populations is likely influenced by loss of reproductive adults,

especially from fished aggregations, sportfishing of large

individuals, removal of juveniles in commercial and recreational catches (Section 5.42), and loss of critical juvenile habitat.

4.33 Recruitment

Epinephelus striatus Data on recruitment of larvae onto

reefs suggest that their onshore transport relies heavily

on cross-shelf winds and currents and occurs in short

pulses during highly limited periods each year (Shenker

et al., 1993). Recruitment of Nassau larvae occurs at an

average 32 mm TL (Eggleston, 1995) and was monitored

for a 75-day period from mid-December through February using channel nets suspended in tidal passes between islands on the edge of the Exuma Sound, Bahamas. Assuming that the full recruitment window was

sampled, 86% of the total annual recruitment of Nassaus

occurred in this area during a single 4-day storm, while

another 10% recruited during a second storm event.

During this sampling period, 13% of all larvae sampled

were Nassau grouper which recruited during particularly short, discrete pulses when compared to other taxa

taken throughout the study. While early recruitment

occurs into both macroalgae and seagrass beds, subsequently higher abundances in macroalgae are probably

due to a combination of active substrate selection behavior for macroalgae and high post-settlement predation in seagrass (Nadeau and Eggleston, 1996) (Section

2.21).

Data on recruitment into the fishery indicate that age

and size first susceptible to capture are 4–7 years and

275+ mm TL, respectively (Table 3). In some areas, most

of the catch is composed of juveniles (e.g. Puerto Rico

and Cuba). Olsen and LaPlace (1979) calculated age of

first capture at 4–5 years, although immature fish of 2

years (< 300 mm TL) were also recruited. Mean size of

recruitment into the fishery in Jamaica was estimated at

570 mm TL (about 5 years) on oceanic banks for

handline and fish trap fisheries; the minimum length

captured was 275 mm TL and the full retention length

was 625 mm TL (Thompson and Munro, 1978). Modal

ages reported for a Cayman Islands aggregation and a

stock in Cuba were 6–8 years (Claro et al., 1990; Bush et

al., 1996), suggesting that individuals were not fully recruited until this age range.

Epinephelus itajara Size of settlement out of the plankton is not known, although a larva close to settlement

was taken at a little over 20 mm TL in a mangrove in

Puerto Rico (Dennis et al., 1991). Jewfish are often recruited into the fishery when still immature, i.e. at 500

mm TL and above (once minimum size limits of 500

mm TL were introduced) (Table 3). Individuals enter

the breeding population at 1,000–1,350 mm TL, based

on catches from aggregations in the eastern Gulf of

Mexico (Bullock et al., 1992).

4.4 Mortality and morbidity

4.41 Mortality rates

Epinephelus striatus Estimates of natural mortality (M),

based on length-frequency data from Nassau grouper

taken on unexploited banks in Jamaica, ranged from
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 43

0.17 to 0.30 (Thompson and Munro, 1978). Total mortality (Z), using length frequency data, was estimated at

0.55 in Cuba. With a low natural mortality (M) determined to be 0.18, this indicates high fishing mortality

(F) of 0.37 (Baisre and Páez, 1981).

Epinephelus itajara Natural mortality (M) of jewfish is

assumed to be 0.15, extrapolating from data on other

grouper species (GMFMC9). Total mortality (Z) of jewfish in the Gulf of Mexico was estimated from the age

distribution as 0.85 for fish greater than 11 years

(GMFMC9). These results indicate a low natural mortality and a high fishing mortality (F) of 0.70.

4.42 Factors affecting mortality

Epinephelus striatus The only known causes of natural

mortality in the Nassau grouper are predation by barracuda, shark, and conspecifics (Section 3.34) and severe

declines in seawater temperature. Sharks were observed

attacking Nassau groupers in spawning aggregations

(Olsen and LaPlace, 1979) and dead Nassau grouper

were reported after a cold spell of 11–14°C in Florida

(Bohnsack, 1983).

Epinephelus itajara There is little information about

natural mortality of jewfish. Gilmore et al. (1978) note

that this species suffers mortality after a cold spell (13°C).

Juveniles of both species are probably prey to other carnivorous fishes such as groupers, snappers, sharks, barracudas. and moray eels (SAFMC24).

4.5 Dynamics of populations

Epinephelus striatus and Epinephelus itajara Little is

known about the dynamics of unexploited stocks of

Nassau grouper and jewfish. Limited information on

their growth rates, mortality, and recruitment is available (Sections 3.43, 4.33, and 4.41). Spawning stock biomass per recruit has not been quantified for either species but landings data clearly show a chronological trend

from abundance to rarity in many areas (e.g. CFMC25;

Sadovy, 1997). Of particular concern has been the rapid

and extreme decline in numbers taken from traditional

aggregation sites. In general, slow-growing, long-lived

species with limited spawning periods and, possibly, with

only a narrow recruitment window (Section 4.33) are

susceptible to overexploitation (Bannerot et al., 1987;

Polovina and Ralston, 1987; Bohnsack1). Such characteristics appear to typify the Nassau grouper and, to a

large extent, the jewfish.

High fishing mortality can annihilate aggregations

(Bohnsack1); since groupers at spawning sites are highly

concentrated and are said to be less cautious, they are

therefore more likely to be caught than at other times.

How important spawning aggregations are to reproductive success has not been quantified but a substantial

proportion of, if not all, annual spawning occurs in aggregations. The extent to which fishing at aggregation

sites disrupts spawning behavior is likewise unknown,

but is probably significant (Section 3.16) (Bannerot et

al., 1987). Moreover, to what extent local recruitment

depends on spawning activity at local aggregations, or

on that occurring upstream, is unknown, making management and conservation decisions for declining stocks

difficult.

Reef fish may be recruitment-limited (see Richards

and Lindeman, 1987; Doherty and Williams, 1988). The

threat of recruitment overfishing increases as reproductive adults decline, or if few juveniles survive to enter

the adult population. Species such as these groupers,

which produce pelagic eggs over limited time periods,

may be subject to highly variable interannual recruitment success, making them particularly vulnerable to

recruitment failure in poor years, or when population

sizes are low.

The results of yield per recruit analyses for other groupers indicate that a large fraction of potential yield is

taken at low levels of fishing mortality and that grouper

stocks are unable to withstand anything other than light

fishing pressure (Huntsman et al., 1983; Sadovy and

Figuerola, 1992); this pattern is likely to also apply to

the Nassau grouper and the jewfish. Since the maximum

biomass of a cohort is attained at older ages, maximum

sustainable yield or maximum yield per recruit is only

reached at low capture levels and when only large fish

are landed (Alverson and Carney, 1975, cited in Bullock et al., 1992). Moreover, with increase in fecundity

with body weight, the stocks’ reproductive potential declines markedly when older, larger fish are selectively

captured.

4.6 The population in the community and

the ecosystem

Epinephelus striatus The Nassau grouper, because of its

former abundance in certain areas, may be a key predator in the ecosystem. This species takes many types and

sizes of food and moves among different habitats, such

as seagrass beds and coral reefs, at different life-history

stages or reproductive phases, or while hunting. Given

its former abundance in some areas, its depletion could

impact the reef community.

Epinephelus itajara The jewfish is the largest American

grouper and one of the two biggest grouper species

worldwide. Due to its large size and reported food habits, this sedentary and site-specific species is likely to have

an impact on its home reef invertebrate and small fish

populations, although removal of a reef’s resident jew-
44 NOAA Technical Report 146

fish has unknown effects on the food web structure and

local prey densities. The role that juvenile jewfish play

in mangrove habitats is likewise unknown.

Jewfish sightings are being used as criteria for success

in the restoration of the Southern Florida ecosystem

(Southern Florida Management and Coordination

Working Group36) based on the fact that, historically,

this species was an abundant predator along the Everglades’ Ten Thousand Islands region.

5 EXPLOITATION

5.1 Fishing equipment

Epinephelus striatus Nassau grouper are fished commercially and recreationally by handline, longline, fish traps,

spearguns, and gillnets. Aggregations are mainly exploited by handlines, or by fish traps, although gillnets

are now used in Mexico. Preferred gears vary regionally

and patterns of gear use are best summarized geographically. In general, traps are used most intensively in insular areas. Recreational fishing with handline is particularly important off Florida.

Bahamas and Caribbean In the Bahamas, handlines,

traps, and spearguns (the latter used with hookah in

recent years) take Nassau grouper (Sadovy, 1997) (Section 5.43). In the U.S. Virgin Islands and Puerto Rico,

reef fish are caught by fish trap with some spearfishing

and handlining (Bolden37). The boats in this fishery are

small, less than 7.9 m long (Appeldoorn and Myers, 1993;

CFMC25). Juvenile Nassau grouper are readily retained

in traps since the mesh size is typically too small (between 44–51 mm) for most to escape.

In the Lesser Antilles, most larger groupers are fished

with handline and with traps from 4–8 m long boats

equipped with 8 to 48-horsepower outboard engines

(Mahon, 1990); since the shelf is so narrow off the Lesser

Antillean Islands, there has been no great need for larger

boats. Groupers are sometimes caught off the deeper

slopes using electric reels or mechanized winches for

hauling traps (Mahon, 1990).

Off Cuba, Jamaica, and Hispaniola, trap fishing is the

primary method for catching grouper (Munro and

Thompson, 1983). Boats are typically non-mechanized

and less than 6 m long (Claro et al., 1990; Baisre, 1993).

The Antillean (arrowhead) fish traps are wooden-framed

with galvanized wire mesh and one or two entrance funnels (Munro, 1983a). The single funnel “chevron traps”

are commonly used in the eastern Caribbean, and the

“S” or “Z” shaped traps, with dual entrance funnels, are

found in Cuba and Jamaica. Most traps have mesh sizes

between 25–50 mm (Munro, 1983a).

Central America In Mexico, handlines were used to

catch groupers until the 1960s, when spearguns became

more common. The efficiency of spearguns led to a

decline in annual landings (Aguilar-Perera, 1994). After spearguns were banned, gillnets were used as barrier nets around aggregation sites. Mean size for gillnet

(20.3 cm mesh) catches at two aggregations sites was

about 600 mm TL (Sosa-Cordero and Cárdenas-Vidal,

1997). In Quintana Roo state, Mexico’s fishers are known

to capture grouper by tying a live female to a line, pulling her up rapidly, and netting the males that follow

her to the surface.

In Belize the speargun and handlines have been used

to fish grouper aggregations since at least the 1940s

(Thompson, 1945; Perkins, 1983), with fish traps increasing after 1986 (Auil16). The fishing boats of Belize comprise either 5–7 m vessels equipped with outboard engines or larger sail-powered boats (Perkins, 1983).

Handlines are often rigged with 3 to 15 hooks per line

(Munro, 1983a).

Florida In the eastern Gulf of Mexico, handlines and

longlines accounted for 80–100% of Nassau grouper

commercially landed, by weight, from 1986–92 (Table

12). Incidental catch of Nassau grouper occurred from

fish traps, with the number of trap-caught groupers increasing since 1984 (GMFMC38). In the 1990s, most

catch from the recreational fishery was from private/

rental boats (Table 13).

Off Florida’s Atlantic coast, Nassau grouper were

caught primarily by handlines (Table 12), although

catches from spearfishing took more than one quarter

of the commercial landings in 1989, 1991, and 1992.

Data prior to 1986 are unavailable because grouper were

not reported by species prior to that year. Most recreational catch in the U.S. Atlantic came from private/

rental boats (Table 13).

Epinephelus itajara In the Gulf of Mexico and the Atlantic, U.S. commercial capture of jewfish was mainly

from handline and speargun, with bycatch from

longlines and trawl fisheries (GMFMC9) (Table 14). The

directed fishery for jewfish primarily depended on

spearfishing; the percentage of jewfish landed through

spearfishing increased substantially after 1984 in the Gulf

and increased between 1988–89 in the Atlantic; from

36 Science Sub-group of the Southern Florida Management and Coordination Working Group. 1993. Federal objectives for Southern

Florida Restoration. Draft report. 71 p.

37 Bolden, S. K. 1994. A summary of biological and fishery data on

red hind (Epinephelus guttatus) and coney (Cephalopholis fulva) stocks

in the U.S. Virgin Islands. NOAA/NMFS Miami Laboratory

Contrib. No. 93/94–32, 33 p.

38 GMFMC. 1989. Amendment Number 1 to the Fishery Management

Plan for the Reef Fish Fishery of the Gulf of Mexico. Tampa, Florida.

356 p.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 45

Table 13

Percentage distribution by boat type of Nassau grouper caught in the U.S. recreational fishery in the Atlantic Ocean and in

the Gulf of Mexico (all states). Fish caught include those reported released alive or dead. Data are from the Marine

Recreational Fishery Statistical Survey, the NMFS headboat catch estimates, and the Texas Parks and Wildlife estimates.

The shore fishing category was not measured in Texas after 1985.

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993

Atlantic catch

Shore fishing 0 0 37.87 4.11 0 0 0 0 0 0 23.60 0 0 0 0

Private/rental

boats 98.72 100 52.36 88.96 70.99 86.70 64.19 99.37 99.62 92.80 70.90 0 99.97 87.26 81.35

Headboats/

charter boats 1.28 0 9.77 6.93 29.01 13.30 35.81 0.62 0.38 7.20 5.51 100 0.03 12.74 18.65

Total number

of fish 107,591 55,494 35,130 52,609 37,022 12,523 63,128 4,998 8,100 7,643 10,026 390 10,922 3,304 2,509

Gulf of Mexico catch

Shore fishing 0 28.55 51.05 0 41.81 1.60 0.95 10.89 12.51 50.95 63.04 23.75 0 4.47 4.19

Private/rental

boats 0 59.81 33.37 100 54.39 97.29 95.59 89.06 86.99 48.83 17.06 76.18 87.28 92.07 95.81

Headboats/

charter boats 100 11.64 15.58 0 3.80 1.11 3.47 0.05 0.50 0.22 19.91 0.07 12.72 3.45 0

Total number

of fish 48,964 27,973 65,823 32,466 30,328 133,547 44,986 120,949 85,240 20,571 36,918 40,969 47,727 27,135 81,031

Table 12

Percent commercial landings of Nassau grouper by gear type for the Atlantic and Gulf of Mexico coasts of Florida from

1986-92. Nets include drift nets, gillnets, and run-around nets; handlines include electric and hydraulic reels, as well as

bandit rigs. Longlines are bottom reeffish longlines. Data from NFMS General Canvass Landings System. [Note that these

landings are all from Florida.]

1986 1987 1988 1989 1990 1991 1992

Atlantic coast

Fish traps 0 0 0 5.81 0 1.6 0

Nets 0 0 0 0 0 1.86 0

Handlines 100 0 54.81 68.49 100 70.8 68.7

Longlines 0 0 45.19 0 0 0 0

Spearguns 0 0 0 25.7 0 25.75 31.3

Total landings (lbs) 9,476 0 582 1,498 3,289 3,072 3,447

Gulf of Mexico coast

Fish traps 13.8 0 0.56 0 4.07 4.19 1.09

Nets 0 0 0 0 0 0 0

Handlines 79.31 0 23.37 38.2 91.08 46.8 98.91

Longlines 0 0 76.06 61.8 4.85 49.01 0

Spearguns 6.89 0 0 0 0 0 0

Total landing (lbs) 5,804 0 3,722 4,283 3,364 2,628 6,065

1986–88, handlines accounted for three quarters of the

landings in the U.S. Atlantic jewfish fishery.

The U. S. recreational fishery, characterized by private and rental boats (Table 15), primarily used spearguns (GMFMC9). Recreational fishers, using handlines,

mostly took small fish because jewfish are difficult to

land at larger sizes (SAFMC24). In the Gulf of Mexico,

the recreational sector took substantially more jewfish

than the commercial sector. The U.S. recreational and

commercial fisheries for jewfish were considerably

smaller in the Atlantic than in the Gulf of Mexico (Tables

14 and 15).

In the Caribbean, jewfish are mainly caught by

spearfishing; their large size, lack of wariness towards divers,

and their sluggish ways make them susceptible to the spear

(CFMC25). Juvenile jewfish are caught in traps (CFMC25).
46 NOAA Technical Report 146

Table 14

Percent commercial landings of jewfish by gear type for the Atlantic and Gulf of Mexico coasts of Florida. Handlines

include electric and hydraulic reels and bandit rigs. Longlines are bottom reeffish longlines. Data from 1979–85 for the

west coast of Florida are from the Gulf of Mexico Reef Fish Fishery Management Plan, Amendment 2, 1990. Data from

1986-90 are from the NMFS General Canvass and Accumulated Landings System. [Note that these landings are all from

Florida]. No data for Atlantic 1979–85.

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990

Atlantic coast

Shrimp trawls 0 0 0 0 9.65

Handlines 74.33 100 78.52 37.89 32.69

Longlines 0 0 0 00

Spearguns 25.67 0 21.48 62.11 57.66

Total landings (lbs) 10,492 17,911 12,931 8,669 1,814

Gulf of Mexico coast

Shrimp trawls 7.3 1.1 1.3 0.8 1.0 0.7 0.1 1.81 1.68 1.99 2.68 0

Handlines 87.2 87.8 81.1 69.8 64.4 67.6 39.7 40.07 39.12 29.13 41.14 75.29

Longlines 0 7.1 11.2 21.1 26.2 20.7 31.4 19.84 14.56 9.87 8.39 8.92

Spearguns 5.4 4.1 6.4 8.3 8.4 11.1 28.8 38.28 44.64 59.00 47.80 15.79

Total landings (lbs) 34,107 41,591 54,950 49,894 68,615 70,374 107,355 108,952 99,951 135,715 93,066 7,488

Table 15

Percentage distribution by boat type of jewfish caught in the U.S. recreational fishery in the Atlantic Ocean and in the Gulf

of Mexico (all states). Fish caught include those reported released alive or dead. Data are from the Marine Recreational

Fishery Statistical Survey, the NMFS headboat catch estimates, and the Texas Parks and Wildlife estimates. The shore

fishing category was not measured in Texas after 1985.

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993

Atlantic catch

Shore fishing 0000 000 000 0000 0

Private/

rental boats 0 100 100 0 0 100 0 0 96.89 99.51 0 0 100 0 0

Headboats/

charter boats 0 0 0 0 100 0 0 100 3.11 0.49 100 0 0 0 0

Total number of fish 0 6,884 995 0 262 6,492 0 1 932 821 610 0 1,163 0 0

Gulf of Mexico catch

Shore fishing 22.08 0 0 0 0 35.11 0 0 0 0 53.85 0 95.50 71.36 0

Private/

rental boats 77.92 64.55 100 100 100 18.02 100 98.10 60.87 0 44.47 99.68 0 28.64 94.21

Headboats/

charter boats 0 35.45 0 0 0 46.87 0 1.90 39.13 100 1.71 0.32 4.50 0 5.79

Total number

of fish 3,823 16,905 14,330 10,175 178 5,240 15,096 8,147 3,159 736 7,138 1,849 2,997 2,772 4,989

5.2 Fishing areas

5.21/5.22 General geographic distribution and range

Epinephelus striatus The center of exploitation of

Nassau grouper is the Caribbean where it is taken at

aggregations and as part of the multi-species, artesanal

fisheries. Historically, the U.S. Virgin Islands and Puerto

Rico’s reef fisheries commonly took Nassau groupers at

aggregation sites. Nassau grouper have also been caught

from several sites off the Jamaican coast and off the

northern coast of the Dominican Republic (Thompson

and Munro, 1983; Sadovy, 1997). In Mexico, at least

seven aggregation sites have been fished along the

Yucatan Peninsula (Aguilar-Perera, 1994). One large

aggregation site off Cay Glory, Belize, has been fished

for many decades and other sites are known (Thompson, 1945). In Cuba, 21 aggregations were fished in the
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 47

last century; only one evidently remains and landings at

that one are declining (Table 1).

In Atlantic waters, Nassaus are caught in the Florida

Keys and the Bahamas (Bohnsack31). Over 20 spawning

locations have been fished in Bahamian waters (Thompson39) (Table 1B), although the current status of many

is unknown. Spawning sites are unknown off Florida.

In the Gulf of Mexico, Nassaus are caught primarily

off southwest Florida, with much reported commercial

and recreational catch from the southwest Florida Keys

39 Thompson, Ronald. 1992. Department of Fisheries, P.O. Box

N 3028, Nassau, Bahamas. Personal commun.

Table 16

Percentage distribution by state of Nassau grouper caught in the U. S. recreational and commercial fisheries (all states).

Recreational fish caught include those reported released alive or dead. Recreational data are from the Marine Recreational Fishery Statistical Survey, the NMFS headboat catch estimates, and the Texas Parks and Wildlife estimates. Commercial data are from NMFS accumulated landings files. TX = Texas; LA = Louisiana; MS = Mississippi; FL-W = Florida West;

FL-E = Florida East; GA = Georgia; SC = South Carolina; NC = North Carolina; Atlantic coast: FL-E, GA, SC, and NC; Gulf

of Mexico coast: TX, LA, MS, FL-W.

1979 1980 1981 1982 1983 1984 1985 1986

Recreational landings

TX 0.0 0.0 0.0 0.0 0.0 1.5 0.0 <0.1

LA 0.0 0.0 3.2 3.2 0.0 1.9 1.5 0.3

MS 0.0 0.0 0.0 0 0.0 <0.1 0.0 0.0

FL-W 31.3 33.5 65.2 35.0 45.0 88 40.1 95.7

FL-E 68.7 66.5 34.8 61.8 55.0 8.6 58.4 4

GA 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

SC 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

NC 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Total number 156,555 83,467 100,953 85,075 67,350 146,070 108,114 125,947

1987 1988 1989 1990 1991 1992 1993

Recreational landings, continued

TX 0.0 0.0 0.0 0.0 0.0 0.0 0.0

LA 0.0 3.1 0.0 0.0 0.0 0.0 0.0

MS 0.0 0.0 0.0 0.0 0.0 0.0 0.0

FL-W 91.7 69.8 78.6 99.1 81.4 89.1 97

FL-E 8.7 27.1 21.4 0.9 18.6 10.4 2.4

GA 0.0 0.0 0.0 0.0 0.0 0.5 0.5

SC <0.1 0.0 0.0 0.0 0.0 0.0 0.0

NC 0.0 0.0 0.0 0.0 0.0 0.0 <0.1

Total number 93,340 28,214 46,944 41,359 58,649 30,439 83,540

1986 1987 1988 1989 1990 1991 1992 1993

Commercial landings

TX 0.0 0.0 0.0 3.3 0.0 0.0 0.0 0.0

LA 0.0 0.0 1.6 0.0 46.5 0.0 0.0 0.0

FL-W 37.1 0.0 78.6 70.4 27.1 46.1 69.8 63.3

FL-E 62.1 0.0 19.8 26.3 26.5 53.9 30.2 36.7

SC 0.6 0.0 0.0 0.0 0.0 0.0 0.0 0.0

Total landings (lbs) 15,633 0 4,737 6,080 12,432 5,700 11,428 7,416

(Table 16, Florida-Gulf of Mexico). Both recreational

and commercial catches of Nassau were higher from the

Florida-Gulf of Mexico than from the Florida-Atlantic

coast (Table 16). After 1991, these differences were probably partially due to fishery regulations banning all capture of Nassau groupers from the U.S. Atlantic waters,

though not from the Gulf of Mexico; harvest is now

banned in all U.S. waters.

Epinephelus itajara In the Caribbean, jewfish were

caught in Kingston Harbor, Jamaica, in shallow waters

(Thompson and Munro, 1983). Jewfish have also been

observed in creeks, lagoons, and estuaries of Belize
48 NOAA Technical Report 146

(Thompson, 1945) but are not commonly taken elsewhere in the region.

Jewfish were seldom caught in the Atlantic, except offshore from Florida on reefs and wrecks (SAFMC10, 24).

Few jewfish were taken between 1986 and 1993 in National Marine Fisheries Service commercial fishery surveys off Georgia or South Carolina (Table 17), although

one individual was landed in the 1970s in Charleston,

South Carolina (Keener-Chavis40).

In the Gulf of Mexico, jewfish were caught mainly in

Florida, but also landed in Alabama, Louisiana, and

Texas (GMFMC9) (Table 17). Until the closure of the

jewfish fishery in 1990, the south Gulf counties of Florida

(i.e. Monroe, Collier, Charlotte, and Lee) accounted for

78% of the total Gulf landings for jewfish, and all of

Florida accounted for 99% of the Gulf jewfish landings

(GMFMC9).

5.23 Depth ranges

Epinephelus striatus The depth range of the Nassau grouper is evidently dependent upon the distribution of natural reefs and hard substrate and, seasonally, on the location of spawning sites (Section 3.16). Off the Florida-Atlantic coast, commercial catches ranged from less than 3

nmi (5.6 km) from shore, to 12 nmi (22.2 km) offshore

and beyond (Table 18). On the Florida-Gulf of Mexico

coast, where hard-bottom areas extend farther offshore,

>59% of the commercial landings between 1986 and 1992

were from more than 12 nmi (22.2 km) offshore (Table

18). In the U.S. Caribbean, on the other hand, where reefs

are found up to a few feet from shore, most reef fish are

caught inshore in territorial waters by small-scale fishers

(Bolden37). Nassau grouper are taken in shallow shelf waters in the Lesser Antilles (Mahon, 1993) and at the shelf

edge in 15–50 m off Cuba (Baisre, 1993) and Jamaica

(Munro, 1983b). From a fishing survey of the Bahamas,

Nassau grouper were common on shallow water banks and

caught in waters less than 110 m deep (Thompson, 1978).

Table 17

Percentage distribution by state of jewfish caught in the U.S. recreational and commercial fisheries (all states). Recreational fish caught include those reported released alive or dead. Recreational data are from the Marine Recreational

Fishery Statistical Survey, the NMFS headboat catch estimates, and the Texas Parks and Wildlife estimates. Commercial

data from 1979–85 are from Gulf of Mexico Reeffish Fishery Management Plan, Amendment 2. Commercial data from

1986–93 are from NMFS General Canvass Landings files. Total commercial landings from 1979–85 do not include Atlantic

catches. (See Table 16 for abbreviations.)

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993

Recreational catch

Texas 22.1 0 0 0 40.5 16.7 9.2 0.7 3.3 0.3 <0.1 0 0 0 0

Louisiana 0 6.8 0 13.8 0 20.9 0 87.1 1.6 00000 0

Alabama 0 0 0 0 0 7.1 0 0 0 0 0 0 0 0 0

Florida–

Gulf of Mexico 77.9 64.2 93.5 86.2 0 0 90.8 12.2 72.3 46.9 92.1 100 72.0 100 100

Florida–

Atlantic 0 28.9 6.5 0 59.5 55.3 0 0 22.8 52.7 7.9 0 28.0 0 0

Total number

of fish 3,823 23,789 15,325 10,175 262 11,732 15,096 8,148 4,091 1,557 7,748 1,849 4,160 2,772 4,989

1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993

Commercial catch

AL,MS,LA, TX 7.3 6.5 9.9 22.0 17.3 9.3 10.9 TX 0.0 <0.1 0.3 0.1 2.0 0.0 0.0 0.0

LA 0.2 1.0 1.8 0.0 19.2 100 0.0 0.0

AL 0.5 0.0 0.5 0.0 0.0 0.0 0.0 0.0

Florida–Gulf

of Mexico 92.7 93.5 90.1 78.0 82.7 90.7 89.1 FL-W 90.6 84.0 88.9 91.4 63.4 0.0 0.0 0.0

FL-E 8.7 15.0 8.5 8.6 15.4 0.0 0.0 0.0

GA 0.0 0.0 0.0 0.0 0.0 0.0 0.0 100

SC 0.0 0.0 <0.1 0.0 0.0 0.0 0.0 0.0

Total landings

(lbs) 36,797 44,478 61,012 63,995 82,942 77,614 120,531 120,317 119,032 152,726 101,868 11,807 798 0 16

40 Keener-Chavis, Paula. 1991. South Carolina Marine Resources

Research Institute, PO Box 12559, SC 29412. Personal commun.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 49

Table 18

Percent commercial landings of Nassau grouper by distance offshore for the Atlantic and Gulf of Mexico coasts of Florida

from 1986–92. Distances are given in nautical miles (nmi). Data are from NMFS General Canvass Landings System.

Distance 1986 1987 1988 1989 1990 1991 1992

Atlantic coast

< 3 nmi from shore 0 0 0 33.04 9.73 33.01 30.37

3–12 nmi from shore 92.55 0 74.05 17.96 8.06 14.52 14.85

12 nmi from shore or greater 7.45 0 25.95 49.00 82.21 52.47 54.77

Total landings 9,476 0 582 1,498 3,289 3,072 3,447

Gulf of Mexico coast

< 3 nmi from shore 0 0 1.96 1.28 9.84 11.57 0

3–12 nmi from shore 14.21 0 1.93 6.70 31.03 9.44 4.34

12 nmi from shore or greater 85.79 0 96.10 92.01 59.13 79.00 95.66

Total landings 5,804 0 3,722 4,283 3,364 2,628 6,065

Epinephelus itajara Jewfish are caught in shallow inshore areas, as well as on deep reefs and wrecks greater

than 12 nmi (22.2 km) offshore (Table 19). A large percentage of the commercial landings are from offshore

in the case of the Gulf of Mexico landings. As the number of jewfish observations by divers declined at known

wrecks, some fishers suggested that jewfish occurred at

greater abundance in waters deeper than 30–45 m (the

practical limit for most diver-spearfishers). However,

explorers of deeper areas in the Gulf of Mexico, using

mixed gases that allowed them more time at depth, did

not observe jewfish deeper than about 50 m (DeMaria17).

In the Caribbean, jewfish have been caught and observed

in shallow water, including Kingston Harbor, Jamaica

(Thompson and Munro, 1983), and inshore off Belize

(Thompson, 1945). Jewfish were included in the shallow inshore fishery of the Lesser Antilles (Mahon, 1993).

Table 19

Percent commercial landings of jewfish by distance offshore for the west and east coasts of Florida. Distance offshore is

indicated in nautical miles (nmi). Data from 1979–85 for the west coast of Florida are from the Gulf of Mexico Reef Fish

Fishery Management Plan, Amendment 2, 1990. Data from 1986–90 are from the NMFS accumulated landings and general

canvass landings files. No data for Atlantic 1979–85.

Distance 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990

Atlantic coast

< 3 nmi offshore 25.67 18.56 12.05 15.85 9.65

3–12 nmi offshore 0 5.16 45.23 16.18 56.23

12 nmi offshore or greater 74.33 76.28 42.72 67.97 34.12

Total landings (lbs) 10,492 17,911 12,931 8,669 1,814

Gulf of Mexico coast

At the shore 0 0 0 0 0 0 0 0 0 0 0 5.4

< 3 nmi offshore 77.4 4.2 3.3 3.2 0.8 1.9 0.1 4.7 7.9 1.7 3.6 10.5

3–12 nmi offshore 8.3 3.6 6.7 4.1 12.0 16.4 9.8 9.7 14.2 14.3 16.5 7.0

12 nmi offshore or greater 14.4 92.1 90.0 92.8 87.2 81.7 90.2 85.6 77.9 84.0 79.9 77.0

Total landings (lbs) 34,107 41,591 54,950 49,894 68,615 70,374 107,355 108,952 99,951 135,715 93,066 7,488

5.3 Fishing seasons

Epinephelus striatus There is geographic variation in the

temporal concentration of fishing activity, but in many

areas much fishing occurs during the reproductive season and spawning aggregations are heavily targeted (Section 5.43); in other areas, there is no apparent temporal association between catch volume and reproductive

season. Commercial capture of Nassau grouper from

U.S. Atlantic and Gulf of Mexico waters (1986–93), for

example, does not reveal any concentration of commercial fishing during the reproductive period in the Atlantic (Fig. 29) and none at spawning aggregations. Elsewhere, however, up to 90% of total annual landings are

taken during the reproductive season. In U.S. Atlantic

waters, recreational catches peaked in the winter

months, corresponding to the spawning season in the
50 NOAA Technical Report 146

nearby Bahamas (Fig. 30). Of the 1991 annual take of

400,000 kg of grouper (mainly Nassaus) landed in the

Bahamas, 40% were taken during months of aggregaFigure 29

Pounds of Nassau grouper, Epinephelus striatus, landed

by month from 1986–93 in the Gulf of Mexico (white

circles) and the Atlantic (black circles) from the U.S.

commercial fishery (NMFS General Canvass Landings

System).

Figure 30

Number of Nassau grouper, Epinephelus striatus, caught seasonally (including catchand-release) by the U.S. recreational fishery in the Gulf of Mexico (white circles)

and the Atlantic (black circles) from 1979–93 (from the NMFS Marine Recreational

Fisheries Statistical Survey, the NMFS headboat survey, and Texas Parks and Wildlife

Department survey).

tion formation (Thompson39). In Cuba, landings data

show that most annual catch is taken between December and January, the spawning season (Claro et al., 1990).

Fishing for Nassau grouper off Belize and Mexico takes

place mainly from late December through January or

February, when spawning occurs, with 20–60% of

Nassaus coming from aggregations in Mexico (Thompson, 1945; Craig, 1966; Aguilar-Perera, 1994; Aguilar41).

Likewise, over 90% of annual landings come from spawning aggregations in the Cayman Islands (Bush42).

Epinephelus itajara There is geographic variation in the

temporal concentration of fishing activity for the jewfish. Commercial and recreational landings from the

Gulf of Mexico indicate that more jewfish were caught

during the reproductive period with peak catches in

August (Figs. 31A and 32) than at any other period, although care should be taken in interpreting these data

since information on effort was not incorporated.

Around Key West, Florida, adults were taken in greater

41 Aguilar, Alfonso. 1992. Centro de Investigaciones de Quintana Roo,

A. P. 424, C. P. 77000, Chetumal, Quintana Roo, Mexico. Personal commun.

42 Bush, P. G. 1992. Protection and Conservation Unit, Department

of the Environment, PO Box 486CT, Grand Cayman, British West

Indies. Personal commun.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 51

Figure 31

Number of pounds of jewfish, Epinephelus itajara, commercially landed by month (A) in the Gulf of Mexico

from 1979–90 and (B) in the Atlantic from 1986–90.

Data from 1979–85 are from Gulf of Mexico Fishery

Management Council (1990); data from 1986–90 are

from NMFS General Canvass Landings System.

numbers by handline in July and August than at other

times (Schroeder, 1924; Thompson, 1945). Similarly, in

Belize, concentrated fishing for jewfish occurred in JulyAugust around the full moon when they were known to

aggregate, presumably to spawn (Thompson, 1945). In

contrast to the Gulf of Mexico and Belize fisheries, Atlantic landings do not reflect any association between

spawning season and catch rates (Fig. 31B). Recreational

catch peaked in September-October from the Atlantic

(Fig. 32); jewfish aggregations have not been reported

in the Atlantic for many years.

5.4 Fishing operations and results

5.41 Fishing effort and intensity

Epinephelus striatus Fishing intensity has increased for

many species of reef fishes over the last few decades,

due partly to improved navigation and introduction of

outboard motors, depth recorders, and power reels

(SAFMC24). However, catch per unit effort (CPUE) is

difficult to quantify for Nassau grouper, since there is

no specific Nassau fishery outside of aggregation periods; instead, catches of this species are combined with

those of other groupers and reef fishes. Quantification

of effort is also confounded by the multiplicity of gears

used, all with different fishing powers (Stevenson, 1981;

Baisre, 1993). Moreover, in the Caribbean, the smallscale fishers land their fish at remote locations, making

collection of reliable catch and effort data difficult

(Stevenson, 1981).

Nassau grouper CPUE, calculated from headboats

fishing off the Florida Keys (SAFMC10) and surveys in

the Bahamas (Thompson, 1978) and Bermuda (Butler

et al., 1993), is generally low or declining. Off the Florida

Keys, from 1978–82, 0.07-0.17 fish were caught per trip,

but this CPUE declined tenfold to 0.01-0.0 fish per trip

from 1984–89 (SAFMC10). Elsewhere in southern Florida,

CPUE was 0.01, or less, from 1983–89 (SAFMC10). Creel

surveys from Biscayne National Park in southern Florida

showed an almost ten-fold decline from 0.18 fish per

trip in 1979 to less than 0.02 in 1987 (Bohnsack31). A

fishing survey in the Bahamas from 1972–75 resulted in

CPUE for Nassau grouper of 0.17 kg/reel hour in 55–

110 m of water and 0.03 kg/reel hour in 110–165 m of

water (Thompson, 1978). In Bermuda, the efficiency of

grouper fishing declined from 1.8 kg of grouper per

trap haul in 1975 to 0.65 kg in 1985 (Butler et al., 1993).

In the insular Caribbean, fishing pressure has increased substantially since the 1970s. In the U.S. Virgin

Islands, the number of small boats increased three-fold

at aggregation sites from 1968–76, with more than 1,000

kg of grouper caught per day. In the 1980s, 10–15 boats

per day fished aggregations, using 6–15 traps per string

and several strings deployed per boat (Beets and Friedlander, 1992); now aggregations no longer form. In the

British Virgin Islands, fishing intensity has been much

lighter and spawning aggregations still formed in the

early 1990s, although their current status is unknown

(Beets and Friedlander, 1992). In Jamaica, fishing surveys conducted in the early 1970s resulted in Nassau

grouper CPUE of 1.4 kg per line hour in 20–30 m of

water and 1.7 kg per line hour in 30–45 m (Munro,

1983b). With the advent of motorized boats and mechanized gears, intense exploitation led to lower catch rates

of all reef fish and the disappearance of some species

from multi-species catches (Stevenson, 1981). A survey

of reef fishes in Jamaica in 1986 revealed no groupers

(Koslow et al., 1988), and by 1989 Nassau grouper were

rarely caught (Sadovy, 1997). In Cuba, the highest CPUE

recorded at an aggregation was 15.7 kg/fisher sea day

in 1977 (Espinosa, 1980).
52 NOAA Technical Report 146

Figure 32

Number of jewfish, Epinephelus itajara, caught by season, including those caught and

released, by the U.S. recreational fishery in the Gulf of Mexico (white circles) and

the Atlantic (black circles) from 1979–93 (from the NMFS Marine Recreational Fisheries Statistical Survey, the NMFS headboat survey, and Texas Parks and Wildlife Department survey).

Off Belize, up until the 1960s, there was little fishing

pressure on grouper stocks (Craig, 1966), but this has

since increased markedly. Aggregations had been fished

with low fishing effort since 1920 (Carter et al., 1994).

From 1955–65, 250–300 boats would regularly fish an

aggregation. By 1982, 1,200 fishers, representing 570

boats, were exploiting grouper spawning grounds

(Perkins, 1983). The recreational fishing industry also

increased because of increased tourism (Perkins, 1983).

In Mexico, at least one aggregation site off the Yucatan

Peninsula had been fished since 1910–20. Landings of

Nassau grouper declined in the late 1960s due to the

introduction of spearguns at aggregation sites (AguilarPerera, 1994).

Epinephelus itajara Prior to the closure of the fishery

in 1990, about 50 spearfishers targeted jewfish in the

1980s in the Atlantic (SAFMC10), while only two to three

fished commercially for jewfish in the Gulf of Mexico.

At one time, few commercial fishers directed any fishing effort to catching jewfish because they did not fetch

the high price of snappers and other groupers

(DeMaria17). The increase in value of jewfish, the availability of better electronic equipment, and the more

widespread knowledge of the location of these fish

caused an increase in overall fishing effort. U.S. commercial landings increased in the 1980s due to elevated

demand and selling prices; the average price per pound

of Gulf jewfish rose from 0.39 US$/lb in 1979 to 0.74

US$/lb in 1987. In Key West, the price of jewfish rose

from 0.5–0.6 US$/lb in 1979 to 1.25 US$/lb in 1987

(GMFMC9). Since the 1980s, the widespread use of the

navigational system LORAN-C increased precision in

relocating productive fishing grounds, including isolated

reefs. The LORAN-C numbers of several wrecks were

published in books and in sport fishing magazines, increasing the likelihood that recreational and commercial fishers could locate these fish. The amount of time

between intensive fishing and stock decline was short,

suggesting that jewfish stocks are easily overexploited

(DeMaria, 1996; Eklund34).

Surveys on effort or intensity of fishing on the jewfish

showed that, off Jamaica in 1970–71, only one jewfish

was caught out of 1,000 traps soaked for 16 days (Munro,

1983c). In Brazil, a preliminary survey carried out in

1994, based on questionnaries, indicated that jewfish

numbers had declined drastically in the previous 10

years, probably due to spearfishing with SCUBA

(Ferreira Padovani and Maida, 1995).

5.42 Selectivity

Epinephelus striatus and Epinephelus itajara Size selectivity for both species is highly variable and depends on
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 53

a combination of location, timing, and gear deployed.

Fishing gears include fish traps, handline, and, to a lesser

extent, speargun and gillnet. Table 3 summarizes ages

and lengths at first capture (Section 4.33).

Many fisheries take large numbers of immature Nassau

groupers because of locations fished and fishing gear

characteristics. In Cuba and elsewhere, juveniles are selected because they are often found in shallower, inshore

waters (e.g. Baisre, 1993). Caribbean fish traps typically

have mesh sizes ranging from 25 to 50 mm which retain

juveniles of these species (Munro, 1983a; CFMC26). In

the U. S. Caribbean, at least 70% of Nassaus landed were

within the immature size range (< 500 mm TL) (Fig.

22). Nassau grouper landed by handline at Biscayne

National Park in southern Florida from 1976–85 were

mostly immature (Fig. 23) (Bohnsack31).

Heavy selective pressure is also placed on mature

spawning fish, since both species are particularly susceptible to capture from easily located spawning aggregations (GMFMC9) (Section 5.43) which are fished by traps,

lines, and, in some areas, spears. Recently, gillnets (20.3

cm mesh) were used for the first time at two aggregation

sites in Mexico taking individuals of 600 mm TL on average (Sosa-Cordero and Cárdenas-Vidal, 1997). The targeting of spawning aggregations results in high fishing mortality (Mahon, 1990) because fish are concentrated and

catchability is high. This selective pressure is likely the primary cause for declines in, and apparent loss of, a number

of well-known spawning aggregations of Nassau grouper

and jewfish. While the genetic consequences of selectively

removing many adults from specific sites are not known,

there is reason for concern: in a study on the orange roughy,

which also aggregates to spawn, loss of heterozygosity was

significantly greater in those aggregations that were most

heavily exploited (Smith et al., 1991).

5.43 Catches

Epinephelus striatus Both commercial and recreational

catches of Nassau grouper declined throughout their

range over the last 20 years, in some cases severely. In

many areas up to 90% of annual commercial landings

come from spawning aggregations. However, aggregations which were once productive now no longer form

at several traditional sites in Belize, the Dominican Republic, Cuba, Honduras, Mexico, the Bahamas, Bermuda, Puerto Rico, and the U. S. Virgin Islands (Fig.

5). In those places where not one aggregation remains

(e.g. Bermuda, Puerto Rico, U. S. Virgin Islands), commercial catches have declined so sharply that either local aggregations must supply a substantial proportion

of the local stocks, or local fishing intensity is so high

that few individuals survive to attain sexual maturity.

Commercial catch exceeded recreational catch everywhere, except in Florida where the reverse was true.

Bahamas, Bermuda, and the Caribbean In the Bahamas, 70% of all grouper landed are Nassau grouper,

which come from at least 23 exploited aggregations

(Department of Fisheries, Government of the Bahamas)

(Table 1b); about 800,000 lbs of Nassaus were landed in

1992 (Sluka et al., 1997a). While Nassau stocks were still

in good condition in the early 1990s (Thompson39), loss

or declines in aggregation catches have been noted.

Forty percent of all groupers are caught between December and February, almost certainly at aggregations

(Thompson39). However, several aggregations no longer

form at traditional sites or have declined markedly in

size. One site off Long Island, for example, fished since

1900, recently dropped from several thousand individuals to about 100 (Colin, 1992). An aggregation site at

Andros Island (off High Cay), considered an important

site by fishers in 1992 (Thompson39), was surveyed in 1998

and contained only scattered individuals at the expected

spawning time (Ray43). In recent years, fishers have expanded their capture methods to include spearfishing with

hookah at aggregation sites (Duncombe44).

In Bermuda, Nassau landings declined 15-fold between 1975–1981, from over 30,000 kg (74,000 lbs) to

under 2,000 kg (4,000 lbs) (Fig. 33). The percentage of

Nassau grouper in the total grouper catch declined from

16%, by weight, in 1975, to less than 1% of all grouper

caught in 1989, a decline greater than for any other

Bermuda grouper monitored (Bannerot et al., 1987;

Butler et al., 1993; Sadovy, 1997). Although the annual

catch of all groupers has recovered somewhat since 1981,

that of the Nassau grouper has remained at a low of about

1,000 kg in 1984 (Butler et al., 1993; Ward45). Much of the

annual catch came from aggregation sites which were fished

until the mid-1970s, when they ceased to form (Sadovy,

1997); now Nassaus are rarely seen inshore.

Landings in the U.S. Caribbean have fallen sharply

within the last three decades. Between 1966 and 1974,

aggregation catches of more than 1,000 kg per day (approximately 300 fish and a significant proportion of the

estimated 2,000–3,000 fish present at the site) were recorded from the U.S. Virgin Islands (Olsen and LaPlace,

1979). Between the aggregation seasons of 1974–75 and

1975–76, however, fishing pressure increased dramatically and total aggregation landings dropped threefold,

from 14,460 kg to 4,930 kg, with a 76% decrease in CPUE

(Olsen and LaPlace, 1979; Beets and Friedlander, 1992).

By the 1980s, spawning aggregations once fished in St.

Thomas and St. Croix no longer formed.

43 Ray, Carleton. 1998. Department of Environmental Sciences, University of Virginia, Charlottesville, VA 22903. Personal commun.

44 Duncombe, Sam. 1992. P. O. Box SS 5905, Nassau, The Bahamas.

Personal commun.

45 Ward, Jack. 1992. Department of Agriculture, Fisheries and Parks,

Flatts, Bermuda. Personal commun.
54 NOAA Technical Report 146

Early this century, the Nassau grouper was reported

as the fourth most commonly landed shallow water species in Puerto Rico, yet none of the traditional aggregations persisted into the 1970s, and by the 1980s few individuals were taken. No data were available on Nassau

grouper landings from the British Virgin Islands, although aggregations evidently still form (Beets and

Friedlander, 1992).

Reported landings from Cuba show marked declines

since the early 1960s (Table 20, Fig. 34). Nassau grouper constituted 7% of total annual landings in 1961–65,

but less than 1.5% of the total landings in 1985–90

(Baisre, 1993; Claro15). Mean annual landings dropped

three to four-fold between the early 1960s and late 1980s,

despite increasing effort (Claro et al., 1990), with over

50% of annual landings coming from aggregations. Of

21 different aggregation areas noted in 1884, (Vilaro

Diaz, 1884) (Table 1B), just one (Banco de Jagua, Oceanic bank off Cochinos Bay) still forms today (Claro15).

Annual landings records are not available from the

Cayman Islands, although reports from fishers in the

1980s indicated that aggregation catches were declining from previous levels (Bush42). Data from the 1990s

indicate that few fish were caught at aggregations in 1997

and 1998, although bad weather may have been partly

to blame (Bush42).

Central and South America In Belize, where more

than 30% of all grouper landed are Nassaus, catches

from aggregations declined about 50% from 12,200 kg

per year to 5,900 kg over a 10-year period ending in the

late 1980s (Carter 1988, 1989), while total annual landings declined from 90,900 kg in 1984 to 21,000 kg in

1991 (Sadovy, 1997). In Mexico, one traditional aggregation, known since 1910–20, attained commercial imTable 20

Landings in metric tons of Nassau grouper reported by the Food and Agriculture Organization of the United Nations

(FAO, 1993). All other countries, besides Cuba and Colombia, did not report their catch by species.

Year 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991

Colombia 5 21 29 88 99 31 25 42 42 47

Cuba 409 377 341 403 262 332 262 263 159 151

Total 414 398 370 491 361 363 287 305 201 198

Figure 33

Commercial landings of Nassau grouper, Epinephelus striatus, by weight (solid line)

(thousands of pounds) and number (dotted line) from 1975–81 in Bermuda

(Bannerot et al., 1987).
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 55

portance in the 1950s but by the end of the 1960s aggregation numbers had declined (Aguilar-Perera, 1994).

An aggregation site in Honduras that produced catches

of 17,000 to 20,000 fish in early 1988 dwindled to about

500 fish by 1991 following intensive fishing in the intervening years (Fine, 1990, 1992).

Landings from Colombia peaked in 1986 and then

dropped dramatically in 1987. Although landings increased from 1987 to 1991, they were still less than half

of those reported for 1986 (FAO, 1993) (Table 20).

Florida U.S. commercial landings data for Nassau

grouper became available in 1986 when this species

was first distinguished from other groupers in the catch.

From 1986 to 1993, Atlantic coast landings declined

from 4,400 kg to less than 1,400 kg, and Gulf of Mexico

landings fluctuated widely, peaking in 1990 at 4,100 kg

(Fig. 35).

Recreational catches of Nassau grouper, including fish

caught and released, have fluctuated widely since first

recorded in 1979. In the Gulf of Mexico, landings peaked

at almost 135,000 individuals in 1984, dropping to below 90,000 in the early 1990s (Table 13). The U.S. Atlantic coast recreational fishery showed a dramatic trend,

with a total catch of over 100,000 fish in 1979, declining

to less than 11,000 from 1986 onwards (Table 13).

Epinephelus itajara Few data are available for the jewfish, with limited information coming only from Florida

for commercial and recreational catches. In the 1960s,

Figure 34

Mean annual landings (in tons) of Nassau grouper, Epinephelus striatus, in Cuban

ports between 1959 and 1988 (modified from Claro et al., 1990).

Figure 35

U.S. commercial landings, in pounds, of Nassau grouper, Epinephelus striatus, from 1986–93 in the Gulf of

Mexico (white circles) and the Atlantic (black circles)

(NMFS General Canvass Landings System).

Gulf of Mexico commercial landings of jewfish were

mainly incidental to the snapper fishery of Yucatan

(GMFMC9). In the U.S., from 1979–88, commercial

catches increased from about 34,000 lbs (15,454 kg) to

136,000 lbs (61,818 kg) and then declined drastically

(Fig. 36, Table 14). Although 5,000–17,000 fish were once

taken recreationally each year, by the early 1990s less
56 NOAA Technical Report 146

than 5,000 were caught and released annually (Table

15).

In the U.S. Atlantic, commercial jewfish landings from

Florida totaled 19,000 lbs (8,600 kg) in 1981, representing an almost fourfold decline from 1974–77 when about

70,000 lbs (31,818 kg) of jewfish were taken (SAFMC24)

(Fig. 36). Annual catch declined almost every year after

1981 until a total ban was implemented in 1990 (Fig.

36). Recreational catch in the Florida-Atlantic has remained very low, with catches of over 1,000 fish recorded

in only three years out of the past 15 (Table 15).

A commercial fishery for jewfish still exists at aggregations off Belize, although landings have declined since

the 1960s when the fleet modernized and expanded

(Wells33). No landings data were available.

6 PROTECTION AND MANAGEMENT

6.1 Regulatory measures

Nassau grouper and jewfish characteristics of slow

growth, large size at sexual maturation, site-specificity,

and concentrated spawning events make them highly

susceptible to overexploitation. They are among the largest members of multi-species fisheries, and even juveniles are highly susceptible to the fishing gears typically

used. For example, in Puerto Rico the mean weight of

all fishes taken with fish traps is 0.3 kg, well below the

1.9 kg of a Nassau grouper at sexual maturity (Sadovy,

1993). It is evident that these groupers cannot sustain

fishing pressure beyond light levels and that in many

areas aggregations disappear either soon after discovery or when fishing effort increases over traditional low

levels, either directly on aggregations or on local stocks

(Sadovy 1994, 1997). The most effective management

approaches are likely to be protection of spawning aggregations and conservation of juvenile and adult biomass through marine reserves in suitably selected habitats.

Epinephelus striatus Most range states have implemented increasingly restrictive regulatory measures for

the Nassau grouper over the last 10–15 years as landings declined (Table 21). For example, in the U.S., the

GMFMC initially imposed a 20 inch TL (510 mm) size

limit, a 5 fish recreational aggregate bag limit on groupers, and a 11.0 million lb (4,500,000 kg) commercial

quota for all groupers combined (excluding jewfish)

(GMFMC38). In 1983, the U. S. SAFMC specified a 12

inch (305 mm) minimum size limit for Nassau grouper,

based on a yield-per-recruit analysis done on the closely

related red grouper, Epinephelus morio (since insufficient

data were available for the Nassau grouper); the analysis indicated that the Nassau was growth overfished

(SAFMC24) and that the maximum sustainable yield required a size limit of 24 inches TL (610 mm), at the

1983 level of fishing effort.

Other management actions included a change in the

fish trap mesh size to greater than 1.5 inch (38.1 mm) hexagonal and a prohibition on trawling of reef fish between

North Carolina and Cape Canaveral (SAFMC24). Nonetheless, by 1991 the SAFMC felt that Nassau grouper was

severely overfished and that all retention should be prohibited (SAFMC46). In 1996, the GMFMC followed suit and

proposed a moratorium on Nassau capture (GMFMC47).

The species is now protected in all U.S. waters.

In 1985, the CFMC instituted a 12 inch TL (30.5 mm)

minimum size limit for Nassau grouper, to be increased

by 1 inch (25.4 mm) increments each year to achieve a

24 inch (609.6 mm) limit by the mid-1990s (CFMC30).

Surveys at the time indicated that 31% of Nassau grouper landed were less than 12 inches, with almost 100%

less than 24 inches (CFMC30) (Fig. 22). By 1990, the

capture of Nassau grouper had become a rare event in

Figure 36

U.S. commercial landings, in pounds, of jewfish,

Epinephelus itajara, from 1979–89 in the Gulf of Mexico

(white circles) and from 1967–81 and 1986–89 in the

Atlantic (black circles) (data from 1979–85 for the Gulf

of Mexico are from Gulf of Mexico Fishery Management

Council 1990; data from 1967–81 for the Atlantic are

from South Atlantic Fishery Management Council, 1983;

data from 1986–89 are from NMFS General Canvass

Landings System).

46 SAFMC. 1991. Amendment Number 4, Regulatory Impact Review,

Regulatory Flexibility Analysis and Environmental Assessment for

Fishery Management Plan for the Snapper Grouper Fishery of the

South Atlantic Region, 87 p. 47 GMFMC. 1996. Amendment #14 to the Fishery Management Plan

for the Reef Fish Fishery of the Gulf of Mexico, 85 p.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 57

U.S. Caribbean waters, indicating severe overfishing, and

the CFMC prohibited any take or possession of this species in 1990 (CFMC48). Because most exploitation is

within territorial waters, the U.S. Caribbean territories

were asked to extend the reef fish federal regulations to

shore (Appeldoorn et al., 1992). As of 1997, the territories had not yet complied with that measure.

Minimum sizes, protection, and quotas have been introduced elsewhere (Sadovy, 1994). In the Bahamas, a

minimum of 1.36 kg is permitted and one aggregation

site was first protected in 1999 (Ray43). In Cuba, in the

mid-1980s, a quota was introduced on take of Nassau

grouper (Claro15). In Bermuda, there is a moratorium

on capture (Luckhurst49).

Other measures aim to protect aggregating animals

through gear restrictions or fishing prohibitions. In

Mexico, for example, spearguns have been prohibited

at aggregations since 1990 (Sosa-Cordero and CárdenasVidal, 1997). Fishing for all groupers is also prohibited

at aggregation sites in Bermuda (Sadovy, 1994). In the

Dominican Republic, no fishing of serranids is allowed

during spawning seasons anywhere and no marketing

of ripe females is permitted (Bohnsack1). In the Cayman Islands, there are at least five aggregation sites; in

1985 three major sites were closed to fishing except for

Table 21

Management measures in effect in 1997 for Nassau grouper and jewfish. The location of the measure, the date of its

implementation, and the type of measure are given. U.S. state waters in Florida are from the coast to 3 miles to the east

(Atlantic) coast and 9 miles to the west (Gulf of Mexico) coast.

Location and date measure implemented

Measure in effect (1997) Nassau grouper Jewfish

Quota Cuba mid-1980s

Minimum size U. S. Gulf of Mexico (1989) 510 mm TL

Bahamas 1.36 kg

Gear restriction Mexico (1993) speargun banned and (1995)

gillnet banned at Mahahual aggregation

Cayman Is (1985) only lines at aggregations

Belize gear restrictions at aggregations

Moratorium U.S. Atlantic (1991) U.S. Gulf of Mexico & Florida State (1990)

U.S. Caribbean (1990) Caribbean Council (1993)

Bermuda (1996) U.S. Virgin Islands territorial waters (1993)

Dominican Republic (mid 1980s) no catch or sale of U.S. Atlantic (1990)

ripe females in spawning season

U. S. Gulf of Mexico (1997)

48 CFMC. 1990. Amendment Number 1 to the Fishery Management

Plan for the Shallow-water Reeffish Fishery, Preliminary Environmental Assessment and Regulatory Impact Review, 10 p.

49 Luckhurst, Brian. 1996. Dept. Agriculture, Fisheries and Parks,

Government of Bermuda, P O Box CR52, Crawl CR BX, Bermuda.

Personal commun.

residents using handline (Tucker and Woodward, 1993;

Bohnsack1). In Belize there are also gear restrictions at

spawning aggregations (Perkins, 1983).

Epinephelus itajara The rapid increase in fishing effort

for jewfish followed by the dramatic decline in catches

led to extreme regulatory measures by the GMFMC. In

1989, the GMFMC approved a 50 inch (1,270 mm) size

limit for jewfish (GMFMC38). This measure was originally considered conservative enough to restore jewfish

stocks. However, reports that stocks were much more

depleted than previously indicated led to Amendment

2 of the Gulf of Mexico Reef Fish Fishery Management

Plan in 1990 which prohibited all capture of jewfish in

federal Gulf waters (GMFMC9). It was the Gulf Council’s

opinion that, without a moratorium, jewfish would become threatened or endangered (GMFMC9). In 1990,

the SAFMC followed the actions of the GMFMC and

enacted an emergency rule prohibiting the take or possession of jewfish in U. S. federal waters.

The CFMC prohibited the capture of jewfish in 1993,

stating that the abundance of jewfish had declined

throughout the U.S. Caribbean, and, possibly, throughout much of the Caribbean (CFMC29). The U.S. Virgin

Islands’ territorial government also made jewfish a protected species, allowing no take in territorial waters

(CFMC29).

The State of Florida banned the capture of jewfish in

1990. Prior to the ban, the size limit on jewfish was 18

inches (457 mm) in Florida waters. Although jewfish are

rarely caught in the Atlantic north of Florida, there are

regulations restricting the take of this species from spe-
58 NOAA Technical Report 146

cial management zones around artificial reefs off South

Carolina and Georgia.

6.2 Environmental changes

Epinephelus striatus and E. itajara The increase in urban, industrial, and tourist developments throughout

these species’ ranges impacts coastal mangroves, seagrass

beds, estuaries, and live coral (Mahon, 1990), reducing

the availability of suitable juvenile and adult habitat. Loss

of juvenile habitat, such as macroalgae and seagrass beds

for the Nassau grouper and mangroves and estuarine

habitats for the jewfish, is likely to negatively affect recruitment rates. Physical damage to spawning sites could

potentially impact reproductive activity if alternative sites

are not acceptable.

Seawater temperature changes, as from global warming, could affect reproduction, since this appears to be

temperature specific (25–26°C), at least in the Nassau

grouper (Section 4.32).

6.3 Regulatory strategies

Epinephelus striatus and E. itajara Management agencies have generally sought to minimize growth and recruitment overfishing and to preserve the spawning

stock biomass per recruit (SSBR). Minimum size limits

address growth overfishing and increase yield per recruit, while the protection of reproductive adults reduces

recruitment overfishing. The SAFMC10 determined that

SSBR should be maintained above 30% for Nassau grouper and above 40% for jewfish to prevent recruitment

overfishing (i.e. stocks should be maintained at 30–40%,

respectively, of their virgin spawning stock biomass)

(Goodyear, 1993). The South Atlantic Fishery Management Plan Development Team (PDT50) believed that the

SSBR for Nassau grouper was probably less than one

percent, and both the SAFMC and the GMFMC concluded that jewfish had been fished far below the 30%

SSBR level. The GMFMC9 suggested that even with a 50

inch (1,270 mm) size limit on jewfish, jewfish SSBR would

be 11% or less, depending on release mortality, which was

believed to be high. With release mortality assumed to be

50%, SSBR was estimated at 1.3%. At such a low SSBR,

stock depletion seemed imminent for both species and

emergency rules were implemented in 1990 (Section 6.1).

In the Caribbean, funds for management are limited

(Mahon, 1993) and, given the small-scale, multi-species

nature of the fisheries, single species management is

precluded. More general management approaches,

however, can reduce capture of immature individuals

and benefit both the Nassau and jewfish. In Cuba, Puerto

Rico, and elsewhere, for example, increases in trap mesh

sizes were proposed to reduce take of immature individuals (Baisre, 1993; CFMC26). The FAO recommended

in 1990 that the Lesser Antilles institute fishing licenses

to limit entry and allow declines in effort through attrition, as well as enforce prohibitions of damaging fishing

gears such as entangling nets and dynamite (Mahon, 1990).

Marine reserves and closures promise to be excellent

approaches to the management of reef fish species that

are relatively site-attached, like groupers, or depend on

critical habitat at some life history stage (Roberts and

Polunin, 1991; PDT51). Belize and the Netherlands

Antilles have established marine parks with fishing closed

in certain zones within the parks (Polunin and Roberts,

1993). There are marine parks in state and federal waters off Florida, although only one, Florida Keys National

Marine Sanctuary, includes no fishing zones (implemented in 1997). In 1986, the Exuma Cays Land and

Sea Park in the Bahamas prohibited all take and appears

to effectively protect Nassau grouper biomass; reproductive output (eggs per hectare) was over six times inside

than outside this park, because of the protection afforded (Sluka et al., 1997b). Mean number of jewfish

spawners increased after a 1990 fishery closure (Fig. 27).

In the early 1990s, due to concern over the status of

these two species, both were named as candidates for

the United States Endangered Species List and both now

appear on the 1996 Red List of the International Union

for the Conservation of Nature (Hudson and Mace,

1996). There are moratoria for both groupers in U.S.

and Bermuda waters.

7 AQUACULTURE

Epinephelus striatus

The Nassau grouper is considered a prime species for

aquaculture since it is a popular and valuable food fish

and stocks are severely depleted (Tucker, 1992a, 1992b).

In recent years, considerable progress has been made

in hatchery spawning and rearing of groupers under

aquarium conditions (Tucker, 1992a; Watanabe et al.,

1995a, 1995b; Tucker et al., 1996).

Female Nassau groupers were induced to ovulate using human chorionic gonadotropin (HCG) injections,

luteinizing hormone-releasing hormone analog (LHRHa), and carp pituitary homogenate (CPH), or combinations thereof (Tucker, 1992b; Kelley et al., 1994; Watanabe

et al., 1995a). Females with mean oocyte diameters rang50 Plan Development Team (PDT). 1990. South Atlantic reeffish: Plan

Development Team report to the South Atlantic Fishery Management Council, 527 p.

51 PDT. 1990. The potential of marine fishery reserves for reef fish

management in the U. S. southern Atlantic. NOAA, NMFS, Coastal

Resources Division, Contr. No. CRD/89-90/04, p. 41.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 59

ing from 482–561 micrometers were suitable for hormone-induced spawning (Watanabe et al., 1995a).

Tucker et al. (1996) described four methods for achieving fertilized eggs, including combinations of induced

or natural ovulation and artificial fertilization with fresh

milt or natural spawning in tanks.

Fertilization rates in artificially induced spawns ranged

from 18–100% and hatching success ranged from 68–

100% (Head et al., 1996; Tucker et al., 1996). Multiple

spawns occurred on consecutive days and hatcheryreared juvenile Nassau groupers grew to 1.5–2.0 kg in 2

years (Tucker and Woodward, 1993).

Larval survival to first feeding can be high, with declines thereafter depending on feeding regime. Survival

of larvae to first feeding in one set of experiments was

65% (Tucker, 1992b) but was found to decline to about

1% by day 62 post-hatching in another (Watanabe et

al., 1996); larval survival declined once the yolk sac was

absorbed. Feeding with oyster trochophores and sieved

rotifers, combined, achieved higher larval survival rates

than feeding with unsieved rotifers alone (Watanabe et

al., 1994) and small prey size was important (Watanabe

et al., 1996). Results of feeding experiments indicated

that cultured juveniles require a dietary protein level

above 55% and an energy to protein ratio of below 28.9

kJ/g for optimum growth (Ellis et al., 1996). Control of

turbulence, salinity, and light intensity can improve survival to the first-feeding stage (Ellis et al., 1997a). Increased

growth and feeding rates occurred with increased water

temperatures (Ellis et al., 1997b).

Following hormone injections, Nassau grouper females produced clutches of between 23,000 and 600,000

mature eggs per kg of body weight, with large females

capable of yielding almost 5,000,000 eggs. Kelley et al.

(1994) reported one to two clutches produced during

the natural reproductive season, with each clutch totaling 50,000–600,000 eggs per kilogram body weight. Head

et al. (1996) found that females could spawn two to three

times at intervals of 28 to 75 days, producing 200,000–

2,000,000 eggs per female (54,000 and 340,000 eggs/kg

body weight) with females ranging in size from 3.5–6.8

kg. Tucker et al. (1991) noted clutches of 500,000 to

700,000 for females ranging from 3–5 kg (166,666 to

140,000 eggs/kg), while Watanabe et al. (1995a) reported stripped females of 4.2–12 kg releasing between

95,000 and 4,750,000 eggs (22,619–395,833 eggs/kg),

with a significant relationship between body weight and

eggs stripped (y=0.385x-0.5589; r2=0.40, n=41, p<0.001;

y is eggs stripped and x is body weight in kg).

Experiments are underway to determine the success

rate of larval Nassau grouper culture and survival of released hatchery-reared juveniles (Roberts et al., 1994;

Watanabe et al., 1995a, 1995b). Although temperature

manipulation might be used to condition Nassau grouper to spawn any month of the year (Tucker et al., 1996),

hatching success was higher between 26–28°C compared

to hatching at 30°C (Watanabe et al., 1995b). Nassau

grouper juveniles (309–367 mm TL) reared from eggs

(n=27) were used to test the feasibility of restocking reefs

(Roberts et al., 1994). Despite some mortality and dispersal, a few tagged fish were observed up to nine

months after release. The potential of Nassau grouper

stock enhancement, as for any other grouper species,

has yet to be determined (Roberts et al., 1994); serious

doubts about the genetic consequences of introductions

and about possible problems of juvenile habitat availability, introduction of maladapted individuals, or inability to locate traditional spawning aggregations, continue to be raised. Certainly aquaculture and stock

enhancement are not solutions to overfishing or species endangerment and are no excuse for avoiding management of vulnerable and overfished fishery resources.

Epinephelus itajara

The jewfish, like the Nassau grouper, is considered to

have prime aquaculture potential (Gomez-Gaspar and

Cervigón, 1987; Roberts, 1990). Wild juveniles have been

raised experimentally on a fresh fish diet in floating cages

in Venezuela (Cervigón, 1983).

Acknowledgments

We are most grateful to the following for their assistance

with information and literature and for access to unpublished data: Alfonso Aguilar, Stephanie Auil, Jim

Beets, Josh Bennett, Jim Bohnsack, Rene Buesa, Lew

Bullock, Phillippe Bush, Rodolfo Claro, Caribbean Fishery Management Council, Jacque Carter, Fernando

Cervigón, Eloy Sosa Cordero, Pat Colin, Don DeMaria,

Karen DeMaria, George Dennis, Michael Domeier, Don

Erdman, Jon Hateley, Bill Head, Phil Heemstra, George

Henderson, Bob Johannes, Wayne Laroche, George

Mitcheson, Bill Parks, Patty Phares, Allyn Powell, Callum

Roberts, John Shenker, Bob Sluka, Ronald Thompson,

John Tucker, Jack Ward, Wade Watanabe, and Sue Wells.

Bonny Bower-Dennis, Jack Javech, and Jeanene McCoy

drafted some of the figures. We thank Jim Bohnsack,

Felicia Coleman, and Amanda Vincent for valuable comments on the manuscript.

Literature Cited

Acero, A. P., and J. Garzon-Ferreira.

1991. Meros, chernas y cabrillas del Caribe colombiano (Pisces: Serranidae: epinephelinae: epinephelini). Caldasia

16(78):355–376.

Aguilar-Perera, A.

1994. Preliminary observations of the spawning aggregation
60 NOAA Technical Report 146

of Nassau grouper, Epinephelus striatus, at Majahual, Quintana

Roo, Mexico. Proc. Gulf Carib. Fish. Inst. 43:112–122.

Aguilar-Perera, A., and W. Aguilar-Dávila.

1996. A spawning aggregation of Nassau grouper Epinephelus

striatus (Pisces: Serranidae) in the Mexican Caribbean. Envir.

Biol. Fish. 45:351–361.

Appeldoorn, R., and S. Meyers.

1993. Puerto Rico and Hispaniola, Part II. In Marine fishery

resources of the Antilles: Lesser Antilles, Puerto Rico and Hispaniola, Jamaica, Cuba, p. 99–158. FAO Tech. Pap. 326, 235 p.

Appeldoorn, R., J. Beets, J. Bohnsack, S. Bolden, D. Matos,

S. Meyers, A. Rosario, Y. Sadovy, and W. Tobias.

1992. Shallow water reef fish stock assessment for the U.S.

Caribbean. NOAA Tech. Memo. NMFS-SEFSC-304, 70 p.

Appeldoorn, R. S., G. D. Dennis, and O. Monterrosa López.

1987. Review of shared demersal resources of Puerto Rico and

the Lesser Antilles region. In Report and proceedings of the

expert consultation on shared fishery resources of the Lesser

Antilles region, p. 36–106. Mayagüez, Puerto Rico, 8–12 September, 1986. FAO Fish. Rep. 383, 278 p.

Baisre, J. A.

1993. Cuba, Part III. In Marine fishery resources of the Antilles:

Lesser Antilles, Puerto Rico and Hispaniola, Jamaica, Cuba,

p. 181–235. FAO Tech. Pap. 326, 235 p.

Baisre, J. A., and J. Páez.

1981. Los recursos pesqueros del archipelago Cubano. WECAF

Stud., 8, 79 p.

Baldwin, C. C., and G. D. Johnson.

1993. Phylogeny of the epinephelinae (Teleostei: Serranidae).

Bull. Mar. Sci. 52(1):240–283.

Bannerot, S. P., W. W. Fox Jr., and J. E. Powers.

1987. Reproductive strategies and the management of snappers and groupers in the Gulf of Mexico and Caribbean. In

J. J. Polovina and S. Ralston (eds.), Tropical snappers and

groupers: biology and fisheries management, p. 561–603.

Westview Press, Boulder, CO.

Bardach, J. E.

1958. On the movements of certain Bermuda reef fishes. Ecology 39(1):139–146.

Bardach, J. E., and D. W. Menzel.

1957. Field and laboratory observations on the growth of some

Bermuda reef fishes. Proc. Gulf Carib. Fish. Inst. 9:106–112.

Bardach, J. E., C. L. Smith, and D. W. Menzel.

1958. Bermuda fisheries research program final report. Bermuda Trade Development Board, Hamilton, 59 p.

Beaumariage, D. S., and L. H. Bullock.

1976. Biological research on snappers and groupers as related

to fishery management requirements. In H. R. Bullis Jr. and

A. C. Jones (eds.), Proceedings Colloquium on snapper-grouper fishery resources of the western central Atlantic Ocean,

p. 86–94. Fla. Sea Grant Coll. Rep. 17, 333 p.

Beets, J., and A. Friedlander.

1992. Stock analysis and management strategies for red hind,

Epinephelus guttatus, in the U. S. Virgin Islands. Proc. Gulf

Carib. Fish. Inst. 42:66–80.

Beets, J., and M. A. Hixon.

1994. Distribution, persistence, and growth of groupers (Pisces: Serranidae) on artificial and natural patch reefs in the

Virgin Islands. Bull. Mar. Sci. 55:470–483.

Bloch, M. E.

1792. Naturgeschichte der ausländischen Fische. Königl.

Akad. Kunst. J. Morino Comp. Berl., Vol. 6, 126 p.

Bloch, M. E., and J. G. Schneider.

1801. Systema Ichthyologiae. Iconibus, Berlin, 584 p.

Boucourt, M.

1868. Descriptions de quelques acanthopterygiens nouveaux

appartenant aux genres Serran et Mesoprion recueillis dans

l’Amerique Centrale. Ann. Sci. Nat. (Zool.), 5(10):222–224.

Böhlke, J. E., and C. G. Chaplin.

1968. Fishes of the Bahamas and adjacent tropical waters.

Livingston Publ. Co., Wynnewood, PA, 771 p.

Böhlke, J. E., and J. E. McCosker.

1973. Two additional west Atlantic gobies (genus Gobiosoma)

that remove ectoparasites from other fishes. Copeia 1973(3):

609–610.

Bohnsack, J. A.

1983. Resiliency of reef fish communities in the Florida Keys

following a January 1977 hypothermal fish kill. Envir. Biol.

Fish 9:41–53.

Bohnsack, J. A., and S. P. Bannerot.

1986. A stationary visual census technique for quantitatively

assessing community structure of coral reef fishes. NOAA

Tech. Rep. NMFS 41, 15 p.

Bohnsack, J. A., and D. E. Harper.

1988. Length-weight relationships of selected marine reef

fishes from the southeastern United States and the Caribbean. NOAA Tech. Memo. NMFS-SEFC-215. 31 p.

Breder, C. M., Jr., and R. F. Nigrelli.

1934. The penetration of a grouper’s digestive tract by a sharptailed eel. Copeia 1934(4):62–164.

Bright, T. J.

1972. Bio-acoustic studies on reef organisms. In B. B. Collette

and S. A. Earle (eds.), Results of the Tektite Program: ecology of coral reel fishes. Bull. Nat. Hist. Mus. Los Angeles

County 14:45–69.

Brownell, W., and C. Gúzman.

1974. Ecología de la Isla de Aves con especial referencia a los

peces. Memoria de la Sociedad de Ciencias Naturales La Salle

98(34), Caracas-Venezuela. Contr. No. 55, p. 91–168.

Brownell, W. N., and W. E. Rainey.

1971. Research and development of deep water commercial

and sport fisheries around the Virgin Islands plateau. Virgin

Islands Ecological Research Station Contrib. No. 3, 88 p.

Buesa, R. J.

1987. Growth rate of tropical demersal fishes. Mar. Ecol. Prog.

Ser. 36:191–199.

Bullock, L. H., and G. B. Smith.

1991. Seabasses (Pisces: Serranidae). Memoirs of the Hourglass Cruises 8(2), 243 p.

Bullock, L. H., M. D. Murphy, M. F. Godcharles, and M. E. Mitchell.

1992. Age, growth, and reproduction of jewfish Epinephelus

itajara in the eastern Gulf of Mexico. Fish. Bull. 90:243–249.

Burnett-Herkes, J.

1975. Contribution to the biology of the red hind, Epinephelus

guttatus, a commercially important serranid fish from the

tropical western Atlantic. PhD dissert., Univ. Miami, Coral

Gables, 154 p.

Bush, P. G., G. C. Ebanks, and E. D. Lane.

1996. Validation of the ageing technique for the Nassau grouper (Epinephelus striatus) in the Cayman Islands. In F.

Arreguin-Sanchez, J. L. Munro, M. C. Balgos, and D. Pauly

(eds.), Biology, fisheries and culture of tropical groupers and

snappers, p. 150–158. ICLARM Conf. Proc. 48, 449 p.

In press. Age, growth, and mortality for Nassau grouper,

Epinephelus striatus, from spawning aggregations around the

Cayman Islands. Fish. Bull.

Butler, J. N., J. Burnett-Herkes, J. A. Barnes, and J. Ward.

1993. The Bermuda fisheries. A tragedy of the commons

averted? Environment 35(1):7–33.

Carpenter, J. S., and W. R. Nelson.

1971. Fishery potential for snapper and grouper in the Caribbean area and the Guianas. In Symposium on investigations
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 61

and resources of the Caribbean Sea and adjacent regions, p.

21–26. FAO 71, 149 p.

Carter, J.

1986. Moonlight mating of the multitudes. Animal Kingdom,

Nov/Dec:62–69.

1988. Grouper mating ritual on a Caribbean reef. Underwater Naturalist 17:8–11.

1989. Grouper sex in Belize. Natural History, Oct:60–69.

Carter, J., G. J. Marrow, and V. Pryor.

1994. Aspects of the ecology and reproduction of Nassau grouper, Epinephelus striatus, off the coast of Belize, Central

America. Proc. Gulf Carib. Fish. Inst. 43:65–111.

Cervigón, F.

1966. Los peces marinos de Venezuela. Vols. I and II. Fund.

La Salle Cienc. Nat., 951 p.

1983. La acuicultura en Venezuela: estado actual y perspectivas. Editorial Arte., Caracas, 121 p.

1994. Los peces marinos de Venezuela, Fundacion Cientifica

Los Roques, C. Fundación Cientifica las Roques (ed.),

Caracas, Venezuela, 2nd edition Vol 3, 295 p.

Choat, J. H., and D. R. Robertson.

1975. Protogynous hermaphroditism in fishes of the family

Scaridae. In R. Reinboth (ed.), Intersexuality in the Animal

Kingdom, p. 263–283. Springer Verlag, Berlin.

Claro, R., A. García-Cagide, L. M. Sierra, and J. P. García-Arteaga.

1990. Características biológico-pesqueras de la cherna criolla,

Epinephelus striatus (Bloch) (Pisces: Serranidae) en la

plataforma cubana. Ciencias Biológicas 23:23–43.

Colin, P. L.

1989. Management and issues. Grouper Watcher 2(1 and 2),

4 p.

1992. Reproduction of the Nassau grouper, Epinephelus striatus

(Pisces: Serranidae) and its relationship to environmental

conditions. Envir. Biol. Fish 34:357–377.

1994. Preliminary investigations of reproductive activity of the

jewfish, Epinephelus itajara (Pisces: Serranidae). Proc. Gulf

Carib. Fish. Inst. 43:138–147.

Colin, P. L., W. A. Laroche, and E. B. Brothers.

1997. Ingress and settlement in the Nassau grouper,

Epinephelus striatus (Pisces: Serranidae), with relationship to

spawning occurrence. Bull. Mar. Sci. 60(3):656–667.

Colin, P. L., D. Y. Shapiro, and D. Weiler.

1987. Aspects of the reproduction of two species of groupers,

Epinephelus guttatus and E. striatus in the West Indies. Bull.

Mar. Sci. 40(2):220–230.

Collette, B. B., and F. H. Talbot.

1972. Activity patterns of coral reef fishes with emphasis on

nocturnal-diurnal changeover. In B. B. Collette and S. A. Earle

(eds.), Results of the Tektite Program: ecology of coral reef

fishes. Bull. Nat. Hist. Mus. Los Angeles County 14:98–124.

Craig, A. K.

1966. Geography of fishing in British Honduras and adjacent

coastal areas. Coastal Studies Institute, Louisiana State University, Tech. Rep. 28, 143 p.

Cuccia, L.

1962. NOGI=fish. Skin Diver June 1962:42–43.

1963. [Untitled.] Skin Diver April 1963:20–21.

Cuvier, G., and A. Valenciennes.

1828. Histoire naturelle des Poissons, Vol. 2. F. G. Levrault,

Paris, 490 p., pls. 9–40.

Dahlgren, C. P.

1998. Population dynamics of early juvenile Nassau grouper:

An integrated modeling and field study. PhD. dissert., Univ.

Maryland, 145 p.

Darcy, G. H., E. Maisel, and J. C. Ogden.

1974. Cleaning preferences of the gobies Gobiosoma evelynae,

G. prochilos and the juvenile wrasse Thalassoma bifasciatum.

Copeia 1974(2):375–379.

DeMaria, K. K.

1996. Changes in the Florida Keys marine ecosystem based

upon interviews with experienced residents. The Nature

Conservancy and Center for Marine Conservation Special

Report. The Nature Conservancy, Key West, FL.

Dennis, G. D., D. Goulet, and J. R. Rooker.

1991. Ichthyoplankton assemblages sampled by night lighting in nearshore habitats of southwestern Puerto Rico. In

Robert D. Hoyt (ed.), Larval fish recruitment and research

in the Americas: Proceedings of the 13th Ann. Fish Conf., p.

89–97. NOAA Tech. Rep. NMFS 95.

Doherty, P. J., and D. McB. Williams.

1988. The replenishment of coral reef fish populations.

Oceanogr. Mar. Biol. 26:487–551.

Domeier, M. L., and P. L. Colin.

1997. Tropical reef fish spawning aggregations defined and

reviewed. Bull. Mar. Sci. 60(3):698–726.

Eggleston, D. B.

1995. Recruitment in Nassau grouper Epinephelus striatus: postsettlement abundance, microhabitat features and ontogenetic habitat shifts. Mar. Ecol. Prog. Ser. 124:9–22.

Eggleston, D. B., J. J. Grover, and R. N. Lipcius.

1998. Ontogenetic diet shifts in Nassau grouper: trophic linkages and predatory impact. Bull. Mar. Sci. 63(1):111–126.

Ehrenbaum, E.

1914. Uber Fische von Westafrika, besonders von Kamerun.

Fischerbote 6(2):289–296.

Ellis, E. P., W. O. Watanabe, S. C. Ellis, J. Ginoza, and A. Moriwake.

1997a. Effects of turbulence, salinity, and light intensity on

hatching rate and survival of larval Nassau grouper,

Epinephelus striatus. J. Appl. Aquacult. 7(3):33–43.

Ellis, S., G. Viala, and W. O. Watanabe.

1996. Growth and feed utilization of hatchery-reared juvenile

Nassau grouper fed four practical diets. Prog. Fish Cult.

58(3):67–172.

Ellis, S. C., W. O. Watanabe, and E. P. Ellis.

1997b. Temperature effects on feed utilization and growth of

postsettlement stage Nassau grouper. Trans. Amer. Fish. Soc.

126(2):309–315.

Erdman, D. S.

1976. Spawning patterns of fishes from the northeastern Caribbean. Contrib. Agric. Pesq., Dep. Agric. Commonwealth

of Puerto Rico 8(2):1–37.

1987. Common names of fishes in Puerto Rico. Tech. Rep.

CODREMAR 3(2):1–44.

Espinosa, L.

1980. Aspectos biológico-pesqueros de la cherna criolla

(Epinephelus striatus Bloch, 1792) en la plataforma cubana y

regiones adyacentes. Inedito Centro de Invest. Pesq.

Ministerio de la Industria Pesquera, Habana, Cuba.

Evermann, B. W.

1900. Fishes and Fisheries of Porto Rico. U.S. Comm. Fish

Fish., 350 p.

FAO.

1993. FAO Yearbook - Fishery Statistics: catches and landings.

Vol. 72. FAO, Rome, 654 p.

Ferreira Padovani, B., and M. Maida.

1995. Projeto Mero: apresentacao e resultados preliminares. Boletim Tecnico-Cientifico do CEPENE- Ibama, vol. 3 (1):201–210.

Fine, J. C.

1990. Groupers in love. Sea Frontiers Jan-Feb 1990:42–45.

1992. Greedy for groupers. Wildlife Conserv. May/June:1–5.

Fish, M. P., and W. H. Mowbray.

1970. Sounds of western north Atlantic fishes: a reference file
62 NOAA Technical Report 146

of biological underwater sounds. The Johns Hopkins Press,

Baltimore, MD, 205 p.

Gilmore, R. G., L. H. Bullock, and F. H. Berry.

1978. Hypothermal mortality in marine fishes of south-central Florida January 1977. Northeast Gulf Sci. 2(2):77–97.

Gobert, G.

1994. Approche historique de l’abondance et de l’exploitation

des grandes espèces de Serranidae en Martinique. Proc. Gulf

Carib. Fish. Inst. 43:446–455.

Gomez-Gaspar, A., and F. Cervigón.

1987. Perspectivas del cultivo de peces marinos en el Caribe

Sur y noreste de Sudamerica. Rev. Latinoam. Acuicult. 34:40–

50.

Goodyear, C. P.

1993. Spawning stock biomass per recruit in fisheries management: foundation and current use. In S. J. Smith, J. J.

Hunt, and D. Rivard (eds.), Risk evaluation and biological

reference points for fisheries management, p. 67–81. Can.

Spec. Publ. Fish. Aquat. Sci. 120.

Greenwood, C. B.

1991. Distribution and feeding habits of larval Epinepheline

groupers in Exuma Sound, Bahamas. MS thesis, Florida Inst.

Technol., Melbourne, FL, 61 p.

Grier, H. J.

1981. Cellular organization of the testis and spermatogenesis

in fishes. Am. Zool. 21:345–357.

Grover, J. J.

1993. Trophic ecology of pelagic early-juvenile Nassau grouper, Epinephelus striatus, during an early phase of recruitment

into demersal habitats. Bull. Mar. Sci. 53:1117–1125.

1994. Feeding habits of early-juvenile Nassau grouper. Bahamas J. Sci. 2(1):22–26.

Grover, J. J., D. B. Eggleston, and J. M. Shenker.

1998. Transition from pelagic to demersal phase in early-juvenile Nassau grouper, Epinephelus striatus: Pigmentation,

squamation, and ontogeny of diet. Bull. Mar. Sci. 62(1):97–

113.

Guitart-Manday, D., and F. Juárez-Fernandez.

1966. Desarrollo embrionario y primeros estudios larvales de

la cherna criolla, Epinephelus striatus (Bloch) (Perciformes:

Serranidae). Academia Ciencias de Cuba, Instituto de

Oceanologica, La Habana 1:35–45.

Halstead, B. W.

1967. Poisonous and venomous marine animals of the world.

Vol. 2 - Vertebrates. U. S. Govt. Printing Office, 1,070 p.

Hateley, J. G.

In press. Preliminary results of a protein electrophoretic analysis of genetic variation, population structure and gene flow

in the Nassau grouper, Epinephelus striatus. Proc. Gulf. Carib.

Fish. Inst. 47.

Hazlett, B., and H. E. Winn.

1962. Sound producing mechanism of the Nassau grouper,

Epinephelus striatus. Copeia 1962:2447–449.

Head, W. D., W. O. Watanabe, S. C. Ellis, and E. P. Ellis.

1996. Hormone-induced multiple spawning of captive Nassau

grouper broodstock. Prog. Fish Cult. 58(1):65–69.

Heemstra, P. C.

1991. A taxonomic revision of the eastern Atlantic groupers

(Pisces: Serranidae). Boletim Museu Municipal do Funchal

43(226):5–71.

Heemstra, P. C., and J. E. Randall.

1993. FAO Species Catalogue. Groupers of the world (Family

Serranidae, Subfamily Epinephelinae). An annotated and

illustrated catalogue of the grouper, rockcod, hind, coral

grouper and lyretail species known to date. FAO Fisheries

Synopsis 16(125), 382 p.

Hildebrand, H. H., H. Chavez, and H. Compton.

1964. Aporte al conocimiento de los peces del arrecife

Alacranes, Yucatan (Mexico). Ciencia (Mex.) 23(3):107–134.

Hinegardner, R., and D.E. Rosen.

1972. Cellular DNA content and the evolution of teleostean

fishes. Amer. Nat. 106:621–644.

Hoese, H. D., and R. H. Moore.

1977. Fishes of the Gulf of Mexico: Texas, Louisiana, and adjacent waters. Texas A&M Univ. Press, College Station, 327 p.

Hudson, E. J., and G. M. Mace.

1996. Marine Fish and the IUCN Red List of Threatened Animals. Report of the workshop held in collaboration with WWF

and IUCN at the Zoological Society of London, April 29-

May 1, 1996, 26 p.

Huntsman, G. R., C. S. Manooch III, and C. B. Grimes.

1983. Yield per recruit models of some reef fishes of the U.S.

South Atlantic Bight. Fish. Bull. 81:679–695.

Johnson, G. D.

1983. Niphon spinosus: a primitive epinepheline serranid, with

comments on the monophyly and intrarelationships of the

Serranidae. Copeia 1983(3):777–787.

Johnson, G. D., and P. Keener.

1984. Aid to identification of grouper larvae. Bull. Mar. Sci.

34:106–134.

Jordan, H.

1917. Rheotropic responses of Epinephelus striatus Bloch. Contr.

Bermuda Biol. Station Research 67:438–454.

Jory, D. E., and E. S. Iversen.

1989. Species profiles: life histories and environmental requirements of coastal fishes and invertebrates (southern

Florida) - black, red, and Nassau groupers. U. W. Fish. Wildl.

Serv. Biol. Rep. 82(11.110), and U. S. Army Corps Engineers,

TR EL-82-4. 21 p.

Kelley, C. D., A. Moriwake, G. Miyamoto, V. Nicol, and W. Watanabe.

1994. The use of LHRH-a for induced spawning of five different species of marine teleost fishes. Abstract for World Aquaculture ’94. World Aquaculture Society. New Orleans, LA.

January 14–18, 1994, 147 p.

Kendall, A. W., Jr.

1979. Morphological comparisons of North American sea bass

larvae (Pisces: Serranidae) NOAA Tech. Rep. NMFS Circ.

428, 50 p.

Koslow, J. A., F. Hanley, and R. Wicklund.

1988. Effects of fishing on reef fish communities at Pedro Bank

and Port Royal Cays, Jamaica. Mar. Ecol. Prog. Ser. 43:201–

212.

Lavenda, N.

1949. Sexual differences and normal protogynous hermaphroditism in the Atlantic sea bass, Centropristis striatus. Copeia

1949(3):185–194.

Leis, J. M.

1986. Larval development in four species of Indo-Pacific coral

trout Plectropomus (Pisces: Serranidae: Epinephelinae) with

an analysis of the relationships of the genus. Bull. Mar. Sci.

38(3):525–552.

1987. Review of the early life history of tropical groupers

(Serranidae) and snappers (Lutjanidae). In J. J. Polovina and

S. Ralston (eds.), Tropical snappers and groupers: biology and

fisheries management, p. 189–238. Westview Press. Boulder.

Lichtenstein. M. G. G.

1822. Die Werke von Marcgrave und Piso uber die Naturgeschichte Brasiliens, erlautert aus den wieder aufgefundenen

Originalzeichnungen. Abbildungen. IV. Fische. Abh. K. Akad.

Wiss. Berlin (1820–1821):267–288.

Lindall, W., N., Jr., W. A. Fable Jr., and L. A. Collins.

1975. Additional studies of the fishes, macroinvertebrates, and
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 63

hydrological conditions of upland canals in Tampa Bay,

Florida. Fish. Bull. 73(1):81–85.

Longley, W. H.

1917. Studies upon the biological significance of animal coloration. I. The colors and color changes of West Indian reef

fishes. J. Exp. Zool. 23(3):533–601.

Longley, W. H., and S. F. Hildebrand.

1941. Systematic catalogue of the fishes of Tortugas, Florida,

with observations on color, habits and local distribution.

Papers Tortugas Lab. 34, 331 p.

Luckhurst, B. E.

1996. Trends in commercial fishery landings of groupers and

snappers in Bermuda from 1975 to 1992 and associated fishery

management issues. In F. Arreguin-Sanchez, J. L. Munro, M. C.

Balgos, and D. Pauly (eds.), Biology, fisheries and culture of

tropical groupers and snappers, p. 277–288. ICLARM, no. 48.

Mahon, R.

1990. Fishery Management Options for Lesser Antilles Countries (Antigua and Barbuda, Barbados, Dominica, Granada,

St. Kitts and Nevis, St. Lucia, St. Vincent and the Grenadines).

FAO Tech. Pap. 313. FAO, Rome.

1993. Lesser Antilles, Part I. In marine fishery resources of

the Antilles: Lesser Antilles, Puerto Rico and Hispaniola,

Jamaica, Cuba, p. 1–98. FAO Tech. Pap. 326, 235 p.

Mandojana, R.

1983. Cleaning station symbiosis on Ricardo’s reef. Oceans

Jan 1983:38–40.

Manter, H. W.

1947. The digenetic trematodes of marine fishes of Tortugas,

Florida. Am. Midl. Nat. 38(2):257–416.

Monsreal, J. F., and J. J. Flores-Abuxapqui.

1988. Prevalence of Vibrio parahaemolyticus in sea products and

in feces of manipulators of foods. Rev. Latinoam. Microbiol.

30(3):223–227.

Moulton, J. M.

1958. The acoustical behavior of some fishes in the Bimini

area. Biol. Bull., Mar. Biol. Lab., Woods Hole, Mass.,

114(3):357–374.

Müller, J., and F. H. Troschel.

1848. The vertebrate animals. In R. H. Schomburgk (ed.), The

history of Barbados. Longman, Brown, Green, and

Longmans, London, 772 p., 7 pls.

Munro, J. L.

1983a. Chapter 1: Coral reef fish and fisheries of the Caribbean Sea. In J. L. Munro (ed.), Caribbean Coral Reef Fishery Resources: ICLARM Studies and Reviews, Vol. 7, p. 1–9.

International Center for Living and Aquatic Resources Management, Manilla, Philippines. Contrib. 125, 2nd ed., 276 p.

1983b. Chapter 4: The composition and magnitude of line

catches in Jamaican waters. In J. L. Munro (ed.), Caribbean

Coral Reef Fishery Resources: ICLARM Studies and Reviews,

Vol. 7, p. 26–32. International Center for Living and Aquatic

Resources Management, Manilla, Philippines. Contrib. 125.

2nd ed., 276 p.

1983c. Chapter 5: The composition and magnitude of trap

catches in Jamaican waters. In J. L. Munro (ed.), Caribbean

Coral Reef Fishery Resources: ICLARM Studies and Reviews,

Vol. 7, p. 33–49. International Center for Living and Aquatic

Resources Management, Manilla, Philippines. Contrib. 125.

2nd ed., 276 p.

Munro, J. L., and R. Thompson.

1983. Chapter 2: The Jamaican fishing industry. In J. L. Munro

(ed.), Caribbean Coral Reef Fishery Resources: ICLARM

Studies and Reviews, Vol. 7, p. 10–14. International Center for Living and Aquatic Resources Management, Manilla,

Philippines. Contrib. 125, 2nd ed., 276 p.

Myrberg, A. A., Jr., A. Banner, and J. D. Richard.

1969. Shark attraction using a video-acoustic system. Mar. Biol.

2:264–276.

Nadeau, D. A., and D. B. Eggleston.

1996. Determinants of Nassau grouper recruitment success

in macroalgae versus seagrass. Abstract. 24th Annual Benthic

Ecology Meeting, Colombia, SC (USA), 7–10 Mar. 1996,

p. 62.

Nagelkerken, W. P.

1981. Distribution and ecology of the groupers (Serranidae)

and snappers (Lutjanidae) of the Netherlands Antilles.

Found. Scientif. Research Surinam and the Netherland

Antilles, 107, 71 p.

1982. Distribution of the groupers and snappers of the Netherlands Antilles. Proc. Fourth Int. Coral Reef Symp. Manila,

1981, 2:479–484.

Odum, W. E.

1971. Pathways of energy flow in a southern Florida estuary.

Univ. Miami Sea Grant Progr. Sea Grant Tech. Bull. 7, 162 p.

Oliver La Gorce, J. (ed.)

1939. The book of fishes. National Geographic Society, Washington, D.C., 367 p.

Olsen, D. A., and J. A. LaPlace.

1979. A study of a Virgin Islands grouper fishery based on a

breeding aggregation. Proc. Gulf Carib. Fish. Inst. 31:130–

144.

Overstreet, R. M.

1969. Digenetic trematodes of marine teleost fishes from

Biscayne Bay, Florida. Tulane Stud. Zool. Bot. 15(4):119–175.

Perkins. J. S.

1983. The Belize Barrier Reef Ecosystem: An assessment of its

resources, conservation status and management. New York

Zoological Society Rep., 148 p.

Poey, F.

1861. Memorias sobre la historia de la Isla de Cuba. Vol. 2.

Havana, 442 p., 19 pls.

Polovina, J. J., and S. Ralston.

1987. Tropical snappers and groupers: biology and fisheries

management. Westview Press, Boulder, CO, 659 p.

Polunin, N. V. C., and C. M. Roberts.

1993. Greater biomass and value of target coral reef fishes in

two small Caribbean marine reserves. Mar. Ecol. Prog. Ser.

100:167–176.

Powell, A. B., and J. W. Tucker Jr.

1992. Egg and larval development of laboratory-reared Nassau

grouper, Epinephelus striatus (Pisces: Serranidae). Bull. Mar.

Sci. 50(1):171–185.

Radakov, D. V., A. D. Motchek, Y. N. Sbikin, R. Claro Madruga, and

 A. Silva Lee.

1975. Acerca de la longitud de los peces comerciales en

capturas de la zona noroccidental de Cuba. Serie Oceanologica. No. 28. Academia de Ciencias de Cuba, Instituto de

Oceanologia, Habana, Cuba, 9 p.

Randall, J. E.

1962. Tagging reef fishes in the Virgin Islands. Proc. Gulf

Carib. Fish. Inst. 14:201–241.

1963. Additional recoveries of tagged reef fishes from the Virgin Islands. Proc. Gulf Carib. Fish. Inst. 15:155–157.

1965. Food habits of the Nassau grouper (Epinephelus striatus).

Assoc. Island Mar. Labs Carib. 6th Meeting. Jan, 1965:13–16.

1967. Food habits of reef fishes of the West Indies. Stud. Trop.

Oceanogr. Inst. Mar. Sci. Univ. Miami No. 5:665–847.

1983. Caribbean reef fishes. Second edition. T.F.H. Publications, Neptune City, NJ. 350 p.

Randall, J. E., and V. E. Brock.

1960. Observations on the ecology of epinepheline and
64 NOAA Technical Report 146

lutjanid fishes of the Society Islands with emphasis on food

habits. Trans. Am. Fish. Soc. 89(1):9–16.

Reed, C. T.

1941. Marine life in Texas waters. Tex. Acad. Sci. Publ. Nat.

Hist. Vol. 2, 88 p.

Richards, W. J., and K. C. Lindeman.

1987. Recruitment dynamics of reef fishes: planktonic processes, settlement and demersal ecologies, and fishery analysis. Bull. Mar. Sci. 41:392–410.

Rivas, L. R.

1964. Western Atlantic serranid fishes (groupers) of the genus Epinephelus. Quart. J. Florida Acad. Sci. 27(1):17–30.

Roberts, C. M., and N. V. C. Polunin.

1991. Are marine reserves effective in management of reef

fisheries? Reviews in Fish Biology and Fisheries 1:65–91.

Roberts, C. M., N. Quinn, J. W. Tucker Jr., and P. N. Woodward.

1994. Long-term adaptation of hatchery reared Nassau groupers to a tropical coral reef environment. Abstract for World

Aquaculture ’94. World Aquaculture Society. New Orleans,

LA. January 14–18, 1994, p. 162.

1995. Introduction of hatchery-reared Nassau grouper to a

coral reef environment. No. Am. J. Fish. Manage. 15(1):159–

164.

Roberts, D. E., Jr.

1990. Snook (Centropomidae) and Grouper (Serranidae)

mariculture in the Gulf of Mexico and the Caribbean Basin.

In J. Barret (ed.), Advances in Tropical Aquaculture: Workshop Held in Tahiti (French Polynesia), Feb. 20-Mar. 4 1989,

Plouzane, France, 9:485.

Roux, C. R., and J. Collignon.

1954. Description d’une nouvelle espèce de poisson, de la

famille des Serranidae, observée sur les côtes de l’Afrique

Equatoriale Francaise: Promicrops ditobo. Bull. Mus. Natl. Hist.

Nat. Paris, 26:473–475.

Sadovy, Y.

1993. The Nassau grouper, endangered or just unlucky? Reef

Encounters, June 1993:10–12.

1994. Grouper stocks of the western central Atlantic: the need

for management and management needs. Proc. Gulf Carib.

Fish. Inst. 43:43–64.

1996. Reproduction of reef fishery species. In N. V. C. Polunin

and C. M. Roberts (eds.), Reef Fisheries, p. 15–59. Chapman

and Hall, London.

1997. The case of the disappearing grouper: Epinephelus

striatus, the Nassau grouper in the Caribbean and western

Atlantic. Proc. Gulf Carib. Fish. Inst. 45:5–22.

Sadovy, Y., and P. L. Colin.

1995. Sexual development and sexuality in the Nassau grouper, Epinephelus striatus (Pisces: Serranidae). J. Fish Biol.

46(6):961–976.

Sadovy, Y., and M. Figuerola.

1992. The status of the red hind fishery in Puerto Rico and

St. Thomas as determined by yield-per-recruit analysis. Proc.

Gulf. Carib. Fish. Inst. 42:23–38.

Sadovy, Y., and D. Y. Shapiro.

1987. Criteria for the diagnosis of hermaphroditism in fishes.

Copeia 1987:136–156.

Sadovy, Y., A. Rosario, and A. Román.

1994. Reproduction in an aggregating grouper, the red hind,

Ephinephelus guttatus. Envir. Biol. Fish. 41:269–286.

Sargent, R. C., and G. E. Wagenbach.

1975. Cleaning behavior of the shrimp Periclimenes anthophilus

(Crustacea: Decapoda, Natantia). Bull. Mar. Sci. 25(4):466–

472.

Schroeder, W. C.

1924. Fisheries of Key West and the clam industry of southern Florida. Appendix XII to the Rep. U. S. Comm. Fish.

1923, 962:1–74

Shapiro, D. Y.

1987. Reproduction in groupers. In J. J. Polovina and S.

Ralston (eds.), Tropical snappers and groupers: biology and

fisheries management, p. 295–327. Westview Press, Boulder,

CO.

Shenker, J. M., E. D. Maddox, E. Wishinski, A. Pearl,

S. R. Thorrold, and N. Smith.

1993. Onshore transport of settlement-stage Nassau grouper

(Epinephelus striatus) and other fishes in Exuma Sound, Bahamas. Mar. Ecol. Prog. Ser. 98:31–43.

Silva Lee, A. F.

1974. Hábitos alimentarios de la cherna criolla Epinephelus

striatus Bloch y algunos datos sobre su biología. Serie

Oceanologica Academia de Ciencias de Cuba 25:3–14.

1977. Nota sobre la coloración y la conducta de la cherna

criolla (Epinephelus striatus Bloch). Academia de Ciencias de

Cuba, Instituto de Oceanologia, Informe Cientifico Tecnico

No. 14, Cuba, 8 p.

Sluka, R., and K. M. Sullivan.

1996. Daily activity patterns of groupers in the Exuma Cays Land

and Sea Park, central Bahamas. Bahamas J. Sci. 3:17–22.

Sluka, R., M. Chiappone, and K. M. Sullivan.

1994. Comparison of juvenile grouper populations in southern Florida and the central Bahamas. Bull. Mar. Sci. 54: 871–

880.

Sluka, R., M. Chiappone, M. de Garine-Wichatitsky, and K. M. Sullivan.

1997a. Benthic habitat characterization and space utilization

by juvenile Epinepheline groupers in the Exuma Cays Land

and Sea Park, central Bahamas. Proc. Gulf Carib. Fish. Inst.

45:23–36.

Sluka, R., M. Chiappone, K. M. Sullivan, and R. Wright.

1997b. The benefits of marine fishery reserve status for Nassau

grouper Epinephelus striatus in the central Bahamas. Proc. 8th

Int. Coral Reef. Symp., p. 1961–1964.

Sluka, R., M. Chiappone, K. M. Sullivan, T. Potts, J. M. Levy,

E. F. Schmitt, and G. Meester.

1998. Density, species and size distribution of groupers

(Serranidae) in three habitats at Elbow Reef, Florida Keys.

Bull. Mar. Sci. 62:219–228.

Smith, C. L.

1959. Hermaphroditism in some serranid fishes from Bermuda. Pap. Mich. Acad. Sci. Arts Letters 44:111–119.

1961. Synopsis of biological data on groupers (Epinephelus and

allied genera) of the western North Atlantic. FAO Fish. Biol.

Synop. No. 23, 61 p.

1965. The patterns of sexuality and the classification of serranid fishes. American Museum Novitates 2207, p. 1–20.

1971. A revision of the American groupers: Epinephelus and

allied genera. Bull. Amer. Mus. Nat. Hist. 146:69–241.

1972. A spawning aggregation of Nassau grouper Epinephelus

striatus (Bloch). Trans. Am. Fish. Soc. 2:257–261.

1978. Serranidae. In W. Fischer (ed.), FAO species identification sheets for fishery purposes, western central Atlantic, fishing area 31. Vols. IV, V. FAO, Rome. [Unpaginated].

Smith, G. B.

1976. Ecology and distribution of eastern Gulf of Mexico reef

fishes. Fla. Mar. Res. Publ. No. 19, 78 p.

Smith, P. J., R. I. C. C. Francis, and M. McVeagh.

1991. Loss of genetic diversity due to fishing pressure. Fisheries Research 10:309–316.

Sosa-Cordero, E., and J. L. Cárdenas-Vidal.

1997. Estudio preliminar de la pesquería del mero Epinephelus

striatus del sur de Quintana Roo, México. Proc. Gulf Carib.

Fish. Inst. 44:56–74.
Sadovy & Eklund: Synopsis of Biological Data on the Nassau Grouper, Epinephelus striatus, and the Jewfish, E. itajara 65

Springer, V. G., and A. J. McErlean.

1962. A study of the behavior of some tagged Southern Florida

coral reef fishes. Am. Mid. Nat. 67:386–397.

Springer, V. G., and K. D. Woodburn.

1960. An ecological study of the fishes of the Tampa Bay area.

Fla. Board Conserv. Mar. Lab. Prof. Pap. Ser. No. 1, 104 p.

Starck, W. A., II.

1968. A list of fishes of Alligator Reef, Florida with comments

on the nature of the Florida reef fish fauna. Undersea Biology 1:5–36.

Starck, W. A., II, and W. P. Davis.

1966. Night habits of fishes at Alligator Reef, Florida.

Ichthyologica 38(4):313–356.

Stevenson, D. K.

1981. A review of the marine resources of the Western Central Atlantic Fisheries Commission (WECAFC) Region. FAO

Fish. Tech. Pap. 211. FAO, Rome, 132 p.

Stewart, V. N.

1987. Grouper. Sea-Stats. No. 8, Jan. 1985, revised May 1987.

Florida Dept. of Natural Resources, 14 p.

Sullivan, K. M., and M. de Garine-Witchatitsky.

1994. Energetics of juvenile Epinephelus groupers: impact of

summer temperatures and activity patterns on growth rates.

Proc. Gulf Carib. Fish. Inst. 43:148–167.

Tabb, D. C., and R. B. Manning.

1961. A checklist of the flora and fauna of northern Florida

Bay and adjacent brackish waters of the Florida mainland

collected during the period July 1957 through September

1960. Bull. Mar. Sci. Gulf Carib. 11(4):552–649.

Thompson, E. F.

1945. The fisheries of British Honduras. Development and

Welfare in the West Indies, Advocate Co., Bridgetown, Barbados. Bull. 21:1–32.

Thompson, R. W.

1978. Results of the UNDP/FAO Bahamas deep water fishery

survey 1972–1975. In Proceedings of the 30th Annual Meeting

of the Gulf and Caribbean Fisheries Institute, Cartagena, Colombia, November 1977, p. 44–70. University of Miami, FL.

Thompson, R., and J. L. Munro.

1978. Aspects of the biology and ecology of Caribbean reef fishes:

Serranidae (hinds and groupers). J. Fish Biol. 12:115–146.

1983. Chapter 7: The biology, ecology and bionomics of the

hinds and groupers, Serranidae. In J. L. Munro (ed.), Caribbean Coral Reef Fishery Resources: ICLARM Studies and

Reviews, Vol. 7, p. 59–81. International Center for Living and

Aquatic Resources Management, Manilla, Philippines.

Contrib. 125, 2nd ed., 276 p.

Townsend, C. H.

1905. Report of the director of the aquarium. Ninth Ann. Rept.

N.Y. Zool. Soc. Biol. 9:89–103.

Tucker, J. W., Jr.

1992a. Spawning serranid fishes in captivity. In Aquaculture ’92

- Growing towards the 21st Century, p. 219.

1992b. Grouper culture for the Caribbean. Progress report. In

M. H. Goodwin, S. M. Kau, and G. T. Waugh (eds.), Proceedings of the 41st Annual Gulf and Caribbean Fisheries Institute, St. Thomas, USVI, Nov. 1988, Vol. 41, p. 587.

1994. Spawning by captive serranid fishes: a review. J. World

Aquacult. Soc. 25:345–359.

Tucker, J.W., Jr., and P.N. Woodward.

1993. Nassau grouper aquaculture. In F. Arreguin-Sanchez, J.

L. Munro, M.C. Balgos, and D. Pauly (eds.), Biology, fisheries and culture of tropical groupers and snappers, p. 363–

377. ICLARM Conf. Proc. 48, 449 p.

1994. Growth and development of domestic juvenile Nassau

groupers. Proc. Gulf Carib. Fish. Inst. 43:389–391.

Tucker, J. W., Jr., P. G. Bush, and S. T. Slaybaugh.

1993. Reproductive patterns of Cayman Islands Nassau grouper (Epinephelus striatus) populations. Bull. Mar. Sci. 52(3):

961–969.

Tucker, J. W., Jr., P. N. Woodward, and D. G. Sennet.

1996. Voluntary spawning of captive Nassau groupers

Epinephelus striatus in a concrete raceway. J. World Aquac.

Soc. 27(4):373–383.

Tucker, J. W., Jr., J. E. Parsons, G. C. Ebanks, and P. G. Bush.

1991. Induced spawning of Nassau grouper Epinephelus striatus.

J. World Aquac. Soc. 22:187–191.

Vilaro Diaz, D. J.

1884. Corrida y arribazon de algunos peces cubanos. Manuel

Gomez de la Maza, Havana, Cuba, 15 p.

Von Bertalanffy, L.

1957. Quantitative laws in metabolism and growth. Q. Rev.

Biol. 32:217–231.

Watanabe, W. O., S. C. Ellis, E. P. Ellis, W. D. Head, C. D. Kelley,

A. Moriwake, C-S Lee, and P. K. Bienfang.

1995a. Progress in controlled breeding of Nassau grouper

(Epinephelus striatus) broodstock by hormone induction.

Aquaculture 138:205–219.

Watanabe, W. O., C. S. Lee, S. C. Ellis, and E. P. Ellis.

1995b. Hatchery study of the effects of temperature on eggs

and yolksac larvae of the Nassau grouper Epinephelus striatus.

Aquaculture 136:141–147.

Watanabe, W. O., C. S. Lee, S. C. Ellis, E. P. Ellis, W. D. Head,

C. D. Kelley, G. Miyamoto, K. Liu, and J. Ginoza.

1994. Experimental culture of larval Nassau grouper (E.

striatus): the effects of temperature on egg and yolksac stages

and of prey quality on survival at first feeding. Abstract for

World Aquaculture ’94, p. 287. World Aquaculture Society.

New Orleans, LA, Jan. 14–18, 1994.

Watanabe, W. O., S. C. Ellis, E. P. Ellis, V. G. López, P. Bass,

J. Ginoza, and A. Moriwake.

1996. Evaluation of first-feeding regimens for larval Nassau

grouper Epinephelus striatus and preliminary, pilot-scale culture through metamorphosis. J. World Aquacult. Soc.

27(3):323–331.

Wing, E. S., and E. J. Reitz.

1982. Prehistoric fishing economies of the Caribbean. J. New

World Archaeology 5(2):13–32.

Wing, E. S., C. A. Hoffman Jr., and C. E. Ray.

1968. Vertebrate remains from Indian sites on Antigua, West

Indies. Carib. J. Science. 8(3 and 4):123–139.

Zinkowski, N.

1971. Julia the jewfish. Skin Diver June 1971:46–50.