U.S. Department 

of Commerce 

August 2001 

(revised November 2001) 

NOAA Technical Report NMFS 153


A Scientific Paper of the FISHERY BULLETIN


Field Guide to Requiem Sharks 

(Elasmobranchiomorphi: 

Carcharhinidae) of the 

Western North Atlantic 

Mark Grace 
NOAA Technical Report NMFS 153 

A Scientific Paper of the Fishery Bulletin 

Field Guide to Requiem Sharks 

(Elasmobranchiomorphi: Carcharhinidae) 

of the Western North Atlantic 

Mark Grace 

August 2001


(revised November 2001)


U.S. Department of Commerce 

Seattle, Washington 
Suggested reference 

Grace, Mark A. 2001. Field guide to requiem sharks (Elasmobranchiomorphi: 

Carcharhinidae) of the Western North Atlantic. U.S. Dep. Commer., NOAA Tech. Rep. 

NMFS 153, 32 p. 

Online dissemination


This report is posted online in PDF format at http://spo.nwr.noaa.gov (click on Technical

Reports link).

Note on revision 

This report was revised and reprinted in November 2001 to correct several errors. Previous 

copies of the report, dated August 2001, should be destroyed as this revision replaces the 

earlier version. 

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the National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161; 

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Although the contents of the Technical Reports have not been copyrighted and may be 

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its purpose an intent to cause directly or indirectly the advertised product to be used or 

purchased because of this NMFS publication. 
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CONTENTS


Introduction 


Methods 


Morphological features of Carcharhinidae (Fig. 1) 


Western North Atlantic Ocean (Fig. 2) 


General description of Carcharhinidae 


Separation sheet for Carcharhinus species without an interdorsal ridge (Fig. 3) 


Separation sheet for Carcharhinus species with an interdorsal ridge (Fig. 4) 


Using the guide 


Discussion 


Key to Carcharhinidae 


Species accounts


Blue shark, Prionace glauca (Fig. 5) 


Tiger shark, Galeocerdo cuvier (Fig. 6) 


Lemon shark, Negaprion brevirostris (Fig. 7) 


Brazilian sharpnose shark, Rhizoprionodon lalandii (Fig. 8) 


Caribbean sharpnose shark, Rhizoprionodon porosus (Fig. 9) 


Atlantic sharpnose shark, Rhizoprionodon terraenovae (Fig. 10) 


Smalltail shark, Carcharhinus porosus (Fig. 11) 


Daggernose shark, Isogomphodon oxyrhynchus (Fig. 12) 


Oceanic whitetip shark, Carcharhinus longimanus (Fig. 13) 


Bull shark, Carcharhinus leucas (Fig. 14) 


Blacknose shark, Carcharhinus acronotus (Fig. 15) 


Finetooth shark, Carcharhinus isodon (Fig. 16) 


Blacktip shark, Carcharhinus limbatus (Fig. 17) 


Spinner shark, Carcharhinus brevipinna (Fig. 18) 


Sandbar shark, Carcharhinus plumbeus (Fig. 19) 


Bignose shark, Carcharhinus altimus (Fig. 20) 


Night shark, Carcharhinus signatus (Fig. 21) 


Galapagos shark, Carcharhinus galapagensis (Fig. 22) 


Dusky shark, Carcharhinus obscurus (Fig. 23) 


Reef shark, Carcharhinus perezi (Fig. 24) 


Silky shark, Carcharhinus falciformis (Fig. 25) 


Acknowledgments 


Literature cited 


1 

1 

3 

4 

6 

7 

8 

8 

9 

11 

12 

13 

14 

16 

17 

18 

19 

21 

22 

23 

24 

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31 

iii 
1 

Abstract—Identification problems are 

common for many sharks due to a general 

lack of meristic characteristics that are typically useful for separating species. Other 

than number of vertebrae and number 

and shape of teeth, identifications are frequently based on external features that 

are often shared among species. Identification problems in the field are most 

prevalent when live specimens are captured and releasing them with a minimum of stress is a priority (e.g., shark 

tagging programs). Identifications must 

be accurate and conducted quickly but 

this can be challenging, especially if specimens are very active or too large to 

be landed without physical damage. This 

field guide was designed primarily for use 

during field studies and presents a simplified method for identifying the 21 species 

of western North Atlantic Ocean sharks 

belonging to the family Carcharhinidae 

(carcharhinids). To assist with identifications a dichotomous key to Carcharhinidae was developed, and for the more 

problematic Carcharhinus species (12 species), separation sheets based on important 

distinguishing features were constructed. 

Descriptive text and illustrations provided 

in the species accounts were developed 

from field observations, photographs, and 

published references. 

Field Guide to Requiem Sharks 

(Elasmobranchiomorphi: Carcharhinidae) 

of the Western North Atlantic 

Mark Grace 

Mississippi Laboratories


Southeast Fisheries Science Center 


NOAA, National Marine Fisheries Service


P.O. Drawer 1207


Pascagoula, Mississippi 39568-1207


Email: Mark.A.Grace@noaa.gov 

Introduction Castro, 1983; Compagno, 1984; Garman, 1997; McEachran and FechCarcharhinids are distributed through- helm, 1998). Existing literature gen­


out temperate and tropical oceans erally includes many shark genera 


with several species occurring world- or addresses world-wide distributions 


wide. Habitats are oceanic beyond the and life history information that may 


continental shelf (oceanic whitetip not be applicable to carcharhinids of 


sharks, Carcharhinus longimanus) and the western North Atlantic Ocean. 


inland into freshwater rivers and This field guide is unique in that it ad­


lakes (bull sharks, Carcharhinus leucas). dresses only carcharhinids from the 


Some species tend to associate with western North Atlantic Ocean. 


bottom while others range throughout 


the water column. All carcharhinids 


are viviparous or ovoviviparous (Com- Methods


pagno, 1984). Carcharhinid sharks are 


a valuable resource worldwide. They Information presented in this field 


are utilized for their flesh, fins, oil, guide was gathered during field inves­


and skin, and are taken recreation- tigations (most notably: Grace1–6, Mitch­


ally (Bonfil, 1994). Some species 


are known to travel long distances, 


occasionally crossing oceans, and are 


considered to be a resource shared 1 Grace, M. 1995. Cruise results for OREGON II 


95-04 (218), coastal shark survey. U.S. Gulf of
 between regions and nations. Mexico, survey depths 18 m–73 m. NMFS Mis-


Carcharhinidae genera can be dif- sissippi Laboratories cruise report, 19 p., P.O. 


ficult to identify due to similar body Drawer 1207, Pascagoula, MS 39568-1207. 

shape, color, and overlapping distri- 2 Grace, M. 1996. Cruise results for OREGON 

II 96-04 (222), coastal shark survey. U.S. Gulf

butions; particularly Carcharhinus spe- of Mexico and Atlantic seaboard from Florida 

cies and Rhizoprionodon species. There to Cape Ann, MA, survey depths 18 m–73 m. 

NMFS Mississippi Laboratories cruise report, are a number of shark identification 12 p., P.O. Drawer 1207, Pascagoula, MS

keys and field guides that are invalu- 39568-1207. 

able for carcharhinid identifications 3 Grace, M. 1997. Cruise results for OREGON 

and those works are fundamental for II 97-04 (227), MEXUS–GULF coastal shark 

survey. Mexican and U.S. Gulf of Mexico from providing a format for accurate iden- Cabo Rojo, Mexico to Florida, and the U.S. 

tifications (Bigelow and Schroeder, Atlantic seaboard from Florida to Cape Hat1948; Baughman and Springer, 1950; teras, NC, survey depths 9 m–55 m. NMFS Mississippi Laboratories cruise report, 15 p., P.O. Springer, 1950; Casey, 1964; Clark and Drawer 1207, Pascagoula, MS 39568-1207. 

von Schmidt, 1965; Schwartz and Bur- 4 Grace, M. 1998. Cruise results for OREGON 

gess, 1975; Hoese and Moore, 1977; II 98-02 (231), MEXUS–GULF, US–Cuba and 

Boschung, 1979; Garrick, 1982, 1985; continued 
2 NOAA Technical Report NMFS 153 

ell7, and Natanson8,9), and from reviews of published references. For species not examined in the laboratory 

or encountered during field investigations (Brazilian 

sharpnose shark, Rhizoprionodon lalandii; Caribbean 

sharpnose shark, Rhizoprionodon porosus; daggernose 

shark, Isogomphodon oxyrhynchus; Galapagos shark, Carcharhinus galapagensis), species accounts and illustrations were developed from published literature. The 

guide’s format emphasizes external distinguishing features important for separating carcharhinids during 

field studies. Species descriptions, maximum size, distribution information, and illustrations are provided for 

all carcharhinid species. Diagrammatic species separation sheets based on important distinguishing features 

are provided for 12 species of the more problematic 

Carcharhinus species. Species separation sheets provide 

a graphic format that can be quickly referenced for 

determining important distinguishing features needed 

in the field. The guide is written primarily for field biologists, but fishermen and naturalists may find the guide 

useful. 

The order for species accounts follows the dichotomous key to Carcharhinidae or the diagrammatic species separation sheets and does not represent carcharhinid phylogeny. Descriptions of morphological features 

(Fig. 1), size ranges, distribution, and illustrations of 

adults accompany each species account. Tooth shape 

is described for the 3–6 upper teeth, on either side 

of the upper jaw midpoint, excluding the rudimentary 

1–2 center upper teeth. Teeth are redrawn from Garrick (1982) unless otherwise noted. The equation for 

dental formulas is as follows: upper left–rudimentary 

center–upper right/ lower left–rudimentary center– 

lower right (e.g., 15–2–15/14–1–14). Dental formulas 

4	 (continued)(Navassa Island coastal shark survey. Mexican Gulf of 

Mexico, survey depths 9 m–55 m; circumference of Cuba and 

Navassa Island, survey depths 27.2 m–412.8 m. NMFS Mississippi 

Laboratories cruise report, 26 p., P.O. Drawer 1207, Pascagoula, MS 

39568-1207. 

5	 Grace, M. 1999. Cruise results for OREGON II 99-02 (233), Oculina Research Reserve and Atlantic coast shark survey(Ft. Pierce to 

Cape Canaveral, FL), survey depths 9 m–55 m. NMFS Mississippi 

Laboratories cruise report, 15 p., P.O. Drawer 1207, Pascagoula, MS 

39568-1207. 

6 Grace, M. 1999. Cruise results for CARETTA 99-01, north-central 

Gulf of Mexico coastal shark survey, survey depths 9 m–55 m. NMFS 

Mississippi Laboratories cruise report, 11 p., P.O. Drawer 1207, Pascagoula, MS 39568-1207. 

7	 Mitchell, K. 1999. Cruise results for FERREL 99-10-SEF, Lutjanus 

campechanus (red snapper) longline cruise. North-central Gulf of 

Mexico, survey depths 64 m–146 m. NMFS Mississippi Laboratories 

cruise report, 12 p., P.O. Drawer 1207, Pascagoula, MS 39568-1207. 

8	 Natanson, L. 1996. Cruise results for PELICAN 96-01 (1–3), survey 

of apex predators—sharks. NMFS Narragansett Laboratory cruise 

report, 13 p., 28 Tarzwell Dr., Narragansett, RI 02882-1199. 

9	 Natanson, L. 1998. Cruise results for DELAWARE II 98-06 (1–3), 

survey of apex predators—sharks. NMFS Narragansett Laboratory 

cruise report, 28 Tarzwell Dr., Narragansett, RI 02882-1199. 

may include ranges or total counts for upper and lower 

teeth. 

Illustrations were developed and drawn by the author from examination of specimens and photographs, 

and when necessary illustrations were adapted from or 

verified with examples from Bigelow and Schroeder 

(1948), Garrick (1982, 1985), Compagno (1984), and 

Garman (1997). Pectoral fins are illustrated depressed 

downward (generally not a natural position) to facilitate graphic representation of dorsal fin origin as related to the pectoral fin axil, pectoral fin inner margin, 

or pectoral fin inner corner. For several species illustrations, feature arrows indicate characteristics of particular importance for identifications. Vertical lines are 

superimposed on illustrations to depict the first dorsal 

fin origin in relation to the pectoral fin, and when applicable the second dorsal fin origin in relation to the 

anal fin. 

Maximum sizes (total length, TL) included in this 

field guide were taken from published references; some 

references were used as a source for maximum size 

based on recommendations for data useful for population assessments (Cortes10). If current publications cited 

older references for maximum sizes, the original source 

is used in the species descriptions. Maximum size information is augmented with survey data for maximum sizes 

recorded during shark surveys (1995–1999) conducted 

by the National Oceanic and Atmospheric Administration, National Marine Fisheries Service (NOAA/NMFS), 

Southeast Fisheries Science Center, Mississippi Laboratories. The NOAA/NMFS surveys encompassed continental shelf waters of the U.S. Gulf of Mexico, the Mexican Gulf of Mexico, the circumference of Cuba, the 

circumference of Navassa Island (a U.S. protectorate, 

Caribbean Sea) and the U.S. Atlantic seaboard from 

the Florida Keys to Cape Ann, MA (Grace1–6, Mitchell7, 

and Thompson11). Even though maximum sizes from 

NOAA/NMFS surveys (standardized gear and randomized survey design) can differ from what is found in 

published references, NOAA/NMFS maximum sizes are 

useful since they reflect what can be currently expected 

during surveys conducted in the western North Atlantic. 

The NOAA/NMFS maximum size information was compiled from Grace1–6, Mitchell7, and Thompson11, and is 

cited in the species accounts as NMFS, n = number of 

specimens examined (e.g., NMFS, n = 123). Total length 

values were taken from actual measurements unless indicated as estimated (e.g., 123.0 cm TL estimated). Max10 Cortes, E. 2000. NMFS Panama City Laboratory, 3500 Delwood 

Beach Rd., Panama City, FL, 32408. Personal commun. 

11 Thompson, P. 1995. Cruise results for RELENTLESS 95-03 (2). 

Coastal shark longline survey. U.S. Atlantic seaboard from Cape 

Canaveral, FL to Cape Hatteras, NC, survey depths 18 m– 

73 m, 8 p., P.O. Drawer 1207, Pascagoula, MS 39568-1207. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 3 

Figure 1


Morphological features and measurement reference points for Carcharhinidae. 
4 NOAA Technical Report NMFS 153 

Figure 2 

Geographic delineations that encompass carcharhinid distributions in the western North Atlantic. 

imum sizes presented in this field guide are not intended as the definitive benchmark for each species but are 

included to assist with separating species. Guide users 

should be aware there is the possibility of capturing 

sharks exceeding maximum sizes presented and extra 

attention should be given for correct identification and 

documentation of those sharks. 

Geographic delineations that encompass carcharhinid distributions in the western North Atlantic are the 

Banks of Newfoundland, Canada, for the northern limit; the equator at the mouth of the Amazon River, South 

America, for the southern limit; west of 40oW longitude 

to the extreme western coasts of the Gulf of Mexico and 

Caribbean Sea (Fig. 2). Unless otherwise cited, species 

distributions in the western North Atlantic Ocean provided in the species accounts were taken from Compagno (1984). 

Nomenclature follows Robins et al. (1991) except 

for the daggernose shark, Brazilian sharpnose shark, 

and the Caribbean sharpnose shark which follow Compagno (1984). Exclusion of Mustelus (family Triakidae) 

from Carcharhinidae follows Castro (1983), Compagno (1984), and Heemstra (1997). Definitions of terms 

used in this guide are as follows: 

Fin origin: Anterior most point of fin base of first dorsal 

fin, second dorsal fin, pectoral fins, pelvic fins, and anal 

fin. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 5 

First or second dorsal fin free rear tip: Trailing free rear 

tip originating posterior to fin base termination of first 

or second dorsal fin. 

Interdorsal ridge: Raised narrow dermal ridge between 

first and second dorsal fins. 

Mouth width: Distance between the mouth corners of 

the upper and lower jaw. 

Pectoral fin axil: Posterior-most point of pectoral fin 

base. 

Pectoral fin inner corner: Angle of pectoral fin posterior to pectoral fin axil. 

Pectoral fin inner margin: Fin margin originating at pectoral fin axil continuing to pectoral fin inner corner. 

Precaudal vertebral centra: Complete vertebral centra 

anterior to forward edge of upper precaudal pit. 

Precaudal pit: Dorsal and ventral notches located anterior to caudal fin origin. 

Prenare length: Distance from anterior origin of nostrils to anterior-most point of snout. 

Postnare length: Distance from anterior origin of nostrils to anterior margin of mouth. 

Snout length: Distance from anterior margin of mouth 

to anterior-most point of snout. 

Carcharhinids that can be identified to species level 

by using the guide’s dichotomous key include the oceanic whitetip shark, smalltail shark (Carcharhinus porosus), tiger shark (Galeocerdo cuvier), daggernose shark, 

lemon shark (Negaprion brevirostris), blue shark (Prionace glauca), and sharpnose sharks (Rhizoprionodon species). The remaining 12 carcharhinids are more difficult to identify to species due to their similarities. 

Characteristics that were found most useful for distinguishing the more difficult species were used as the 

basis for species separation sheets (Figs. 3 and 4). Distinguishing features chosen for separation sheets were 

those effective for grouping similar species. Some distinguishing features were not used in separation sheets 

because they were difficult or impractical to determine 

from live specimens (e.g., number of precaudal vertebral centra). 

Identification of Carcharhinus species is facilitated by 

division into two groups (exclusive of the smalltail shark 

and oceanic whitetip shark); five without an interdorsal ridge (Fig. 3), and seven with an interdorsal ridge 

(Fig. 4). Further division of each group is dependent 

on the first dorsal fin origin in relation to the pectoral 

fin. Species determination is completed by creating other subgroups based on snout shape, pectoral fin shape, 

or fin pigmentation. 

It can be difficult to identify Rhizoprionodon species 

based on external features alone and it may be necessary to determine the number of vertebral centra when 

possible. Values for precaudal and total vertebral centra are provided for Rhizoprionodon species (Compagno, 1984). The copper shark (Carcharhinus brachyurus) 

and the silver tip shark (Carcharhinus albimarginatus) 

were not included in this guide even though Compagno (1984) indicates their distribution is possible in the 

western North Atlantic Ocean; however, their presence 

has not been scientifically confirmed. 

General description of Carcharhinidae 

Members of Carcharhinidae are variously distinguished 

by the presence of precaudal pits; lack of spiracles 

(present on tiger sharks and occurring rarely on lemon 

sharks, Compagno, 1988); bladelike teeth with single 

cusps; first dorsal fin origin usually above pectoral fin 

or slightly posterior to pectoral fin inner corner (except 

on the blue shark with the dorsal fin base midpoint 

closer to pelvic fin origin than pectoral fin axil); second 

dorsal fin smaller than first dorsal fin and above anal 

fin (second dorsal fin and first dorsal fin almost equal 

size on lemon sharks); fifth gill slit over or posterior to 

pectoral fin origin; no fleshy keels along sides of caudal 

peduncle (except on tiger sharks and blue sharks); welldeveloped nictitating membrane along eye socket lower 

margin. 

Freshly caught carcharhinids have a variety of body 

colors that are often muted color mixed with gray tones 

dorsally, and pale yellow or white laterally or ventrally; 

the exception is the blue shark which is counter shaded brilliant blue above and white below. Juvenile tiger 

sharks have distinct mottling and vertical bars that often fade with age; Atlantic sharpnose sharks (Rhizoprinodon terraenovae) often have light spots along the body. 

Juveniles for most species have fins tipped dusky or 

black. Adults generally have dusky fin tips, however, in 

the western North Atlantic Ocean blacktip sharks (Carcharhinus limbatus) greater than 80.0 cm TL have black 

fin tips except for a pale or white anal fin (Branstetter, 

1982); all fin tips are black on spinner sharks (Carcharhinus brevipinna) greater than 80 cm TL (Branstetter, 

1982); oceanic whitetip sharks have white fin tips on the 

first dorsal fin, pectoral fin, and caudal fin. 

Sharks that may possibly be misidentified as belonging to Carcharhinidae include species of Odontaspididae (sand tiger sharks), and Lamnidae (mackerel 
Figure 3 

Separation sheet for Carcharhinus species without an interdorsal ridge. 

1 First dorsal fin origin usually over pectoral fin inner margin. 2 First dorsal fin origin usually anterior to or over pectoral fin axil. 3 Refer to species descriptions f

80 cm. 4 Fin tip pigmentation may be faded for larger specimens. 5 First dorsal fin origin usually posterior to pectoral fin inner corner. 

Carcharhinus species without an interdorsal ridge. 

Snout bluntly rounded and short. Upper teeth broad and serrated. First dorsal fin high and triCarcharhinus leucas, Fig. 14. 

First dorsal fin origin anterior to or over pectoral fin axil. 

First dorsal fin origin over pectoral fin inner margin. First dorsal fin origin posterior to pectoral fin inner corner. 

Snout moderately rounded. Long gill slits; length twice the eye diameter. Upper teeth narrow 

Finetooth shark—Carcharhinus isodon, 1 Fig. 16. 

Snout moderately rounded; tip with dusky or black blotchand with distinct notch. Blacknose shark—Carcharhinus acSnout moderately rounded; tip without dusky or black length twice the eye diameter. Upper teeth narrow and nserrated; without distinct notch. Finetooth shark—CarchaSnout bluntly rounded and short. First dorsal fin high ateeth broad and serrated. Bull shark—Carcharhinus leu

Fin tips dusky or not distinctly pigmented. Most fins with black tips. 

Pectoral fins short and broad. Pectoral fins long and broad. 

For specimens greater than 80 cm TL,3 first dorsal fin, second dorsal fin, p

caudal fin lobe with distinct black tips;4 anal fin white or pale. Dark chevron-sh

originates near pectoral fin. Blacktip shark, Carcharhinus limbatus, Fig. 17. 

For specimens greater than 80 cm TL,3 first dorsal fin, second dorsal fin, pec

lower caudal fin lobe with distinct black tips.4 Often with a dark chevron-sha

originates near pectoral fin. Spinner shark—Carcharhinus brevipinna, 5 Fig. 18. 

Snout tip with dusky or black blotch. Blacknose shark—Carcharhinus acronotus, 1 Fig. 15. 

For specimens greater than 80 cm TL,3 first dorsal fin, second dorsal fin, pectoral fins, anal fin, and low

distinct black tips.4 Spinner shark—Carcharhinus brevipinna, Fig. 18. 
Figure 4 

Separation sheet for Carcharhinus species with an interdorsal ridge. 

1 First dorsal fin origin usually over pectoral fin inner margin. 2 First dorsal fin origin usually anterior to or over pectoral fin axil. 

Carcharhinus species with an interdorsal ridge. 

Snout bluntly rounded. First dorsal fin high and triangular. Sandbar shark—Carcharhinus plumbeu

First dorsal fin origin anterior to or over pectoral fin axil. 

First dorsal fin origin over pectoral fin inner margin. 

First dorsal fin origin posterior to pectoral fin inner corner. 

Snout moderately or sharply rounded. First dorsal fin low with angular or slightly rounded apex. PBignose shark—Carcharhinus altimus, 1 Fig. 20. 

Snout long and moderately or sharply rounded. Snout bluntly rounded. 

Prominent nasal lobes. Upper teeth long, moderately broad, symmetrical, and Bignose shark—Carcharhinus altimus, Fig. 20. Second dorsal fin free rear tip at least twice as long as second dorsal fin height. distinct notch, oblique cusps and prominent basal serrations. Night shark—CarFig. 21. 

First dorsal fin high and triangular; origin usually closer to pectoral fin axil thmargin midpoint. Pectoral fins broad. Sandbar shark—Carcharhinus plumbeus,2 

First dorsal fin moderate with angular apex; origin closer to pectoral fin innthan pectoral fin inner corner. Pectoral fins broad. Usually found along oceanshark—Carcharhinus galapagensis, Fig. 22. First dorsal fin usually low with sharply rounded apex; origin closer to pectora

to pectoral fin inner margin midpoint. Pectoral fins tapered with falcate rear along continental coastlines. Dusky shark—Carcharhinus obscurus, Fig. 23. 

First dorsal fin moderate with angular apex; origin closer to pectoral fin inner ral fin inner margin midpoint. Pectoral fins tapered and without falcate rear mpectoral fin tips, pelvic and anal fin tips, and lower caudal fin lobe tip often dReef shark—Carcharhinus perezi, Fig. 24. 

Pectoral fins without distinctly falcate rear margins. Snout is of moderate length and moderately rounde

rhinus falciformis, Fig. 25. 

Pectoral fins with falcate rear margins. Snout bluntly rounded. Dusky shark—Carcharhinus obscurus,1 Fig

Pectoral fins without distinctly falcate rear margins. Snout long and sharply rounded. Upper teeth with cusps, and prominent basal serrations. Night shark—Carcharhinus signatus, 1 Fig. 21. 
8 NOAA Technical Report NMFS 153 

sharks). Members of these families have all five gill slits 

anterior to the pectoral fin origin; sand tiger sharks 

have short pectoral fins and large pelvic fins; mackerel 

sharks have lunate caudal fins (upper and lower caudal 

fin lobes of almost equal length) and well-developed 

caudal keels that extend past the caudal fin origin. 

Using the guide 

Once it is determined that a specimen is a species of 

Carcharhinidae, use the dichotomous key to Carcharhinidae to select the species or genus that represents 

the specimen, then refer to the appropriate species 

account or separation sheet. Prior to using the guide 

during field studies, familiarization with the dichotomous key is important for determining which species 

will not need to be identified by using separation sheets. 

This will save time for identifying the least problematic 

species and will allow direct referencing of separation 

sheets for the more problematic species. It is helpful to 

have copies of separation sheets included with on-deck 

sampling gear for quick referencing. Use the process of 

elimination to work through the separation sheets. Species that possess a diagnostic character that is variable 

will be listed more than once on the separation sheet. 

If identification characteristics presented on separation 

sheets are not discernible, the identification process 

should not proceed. 

Species accounts include information pertaining to 

distinguishing features, ontogenetic changes, maximum 

size, distribution, and number and shape of teeth. Determination of the first dorsal fin origin in relation to 

the pectoral fin is important for identifying most species of Carcharhinus. If it is difficult to make this determination, when feasible use some type of straight edge 

or string held vertical to landed specimens beginning 

at the first dorsal fin origin extending in a straight line 

down to the pectoral fin. It is helpful to orient specimens too large to land dorso-ventrally to assess the dorsal fin origin from an overhead or side view. 

When specimens are landed, morphometric characteristics in the species descriptions (i.e., snout length 

compared to mouth width) will be helpful for separating species. For specimens too large to land, morphometric characteristics will be of limited value depending on the specimen’s condition (highly active or 

passive). If morphometric measurements are possible, 

verification with Garrick (1982, 1985) is recommended 

for Carcharhinus species, and Compagno (1984) is recommended for Rhizoprionodon species; distinguishing 

other carcharhinids does not require morphometric 

measurements. The second dorsal fin origin in relation 

to the anal fin base is an important feature, especially 

for distinguishing the smaller-sized carcharhinids, Rhizoprionodon species, smalltail sharks, blacknose sharks, 

and finetooth sharks, all with maximum sizes less than 

164.0 cm TL. Most small sharks can be landed and determining the position of the second dorsal fin is not 

difficult. 

Discussion 

To facilitate identifications, every effort has been made 

to utilize unique external features, however, some species closely resemble each other and several external features must be used for accurate identifications. Sharks 

with an interdorsal ridge and the dorsal fin origin over 

the pectoral fin inner margin are most difficult to identify. This group includes the sandbar shark (Carcharhinus plumbeus, it is uncommon for dorsal fin origin to be 

over the pectoral fin inner margin), bignose shark (Carcharhinus altimus), night shark (Carcharhinus signatus), 

Galapagos sharks, dusky shark (Carcharhinus obscurus), 

and reef shark (Carcharhinus perezi); these six species 

share features used on the separation sheet for carcharhinids with an interdorsal ridge (Fig. 4). They are 

grouped separately from other species through the process of elimination but ultimately are distinguished 

from each other by characteristics that can include 

the snout, pectoral fin, teeth, habitat, and distribution. 

Careful attention to detail should be exercised when 

separating similar species (species grouped together 

on the species separation sheets); there is no reliable 

method for identifications if key characteristics are not 

confirmed. It is recommended that species descriptions 

for similar species be reviewed before establishing an 

identification. 

When time permits and release of specimens with a 

minimum of stress is not a concern, detailed taxonomic 

references offering full descriptions should be used to 

verify identifications. Taxonomic references often utilize proportional measurements and meristics (vertebral counts and dental formulas) to separate species, 

and generally provide detailed species descriptions and 

illustrations of important characteristics. Bigelow and 

Schroeder (1948) state adults of Carcharhinus, “resemble one another so closely in general appearance that 

little or no dependence can be placed on published reports of occurrence unless accompanied by some indication as to fins, teeth, etc., . . . they are separable by 

characters so precise and so little variable that specific 

identification is not difficult, although attention to detail is required.” 

Identifications can be difficult for specimens not captured or landed, however, species identification under 

these circumstances can be accomplished using combinations of characteristics, including not only external 

features but also locality and behavior. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 9 

Key to Carcharhinidae 

1a 	 First dorsal fin base midpoint closer to pectoral fin axil than pelvic fin origin, 

or at most midway between . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

1b 	 First dorsal fin base midpoint closer to pelvic fin origin than pectoral fin axil. 

Pectoral fins long and tapered. Dark blue dorsally, brilliant blue sides, 

white ventrally (Fig. 5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . blue shark, Prionace glauca 

2a No caudal keels. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 

2b 	 Caudal keels present. Snout bluntly rounded and short. Small spiracles posterior 

to eyes. Upper caudal fin lobe elongate with pointed apex. Body can be 

noticeably mottled or with vertical stripes (Fig. 6). . . . . . . . . . . . . . . . . . . . . . . . . . tiger shark, Galeocerdo cuvier 

3a Second dorsal fin much smaller than first dorsal fin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 

3b 	 Second dorsal fin almost as large as first dorsal fin. Pectoral fins broad 

and not elongate; pelvic and anal fins about equal size (Fig. 7) . . . . . . . . . . lemon shark, Negaprion brevirostris 

4a Second dorsal fin origin over or posterior to anal fin base midpoint. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 

4b Second dorsal fin origin anterior to anal fin base midpoint . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 

5a 	 Labial furrows well developed and visible in profile view. Teeth smooth 

or weakly serrated (Figs. 8, 9, and 10). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . sharpnose sharks, Rhizoprionodon 

5b 	 Labial furrows not well developed and generally not visible in 

profile view. Teeth with distinct serrations (Fig. 11) . . . . . . . . . . . . . . . . . . smalltail shark, Carcharhinus porosus 

6a 	 Snout elongate and flattened in profile, appears triangular 

from overhead view (Fig. 12) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . daggernose shark, Isogomphodon oxyrhynchus 

6b Snout not elongate and flattened in profile, does not appear triangular from overhead view. . . . . . . . . . . . . . 7 

7a 	 First dorsal fin apex and pectoral fin apex broadly rounded, 

most fins with white tips (Fig. 13) . . . . . . . . . . . . . . . . . . . . . . . . oceanic whitetip shark, Carcharhinus longimanus 

7b 	 First dorsal fin apex and pectoral fin apex angular or sharply rounded; 

not broadly rounded with white tips . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 

8a Interdorsal ridge present (Fig. 4) 

8b No interdorsal ridge (Fig. 3) 
10 NOAA Technical Report NMFS 153 

Species accounts 

Blue shark, Prionace glauca (Fig. 5) 

No interdorsal ridge. First dorsal fin base midpoint 

closer to pelvic fin origin than pectoral fin axil. Pectoral fins long and moderately falcate. Snout sharply 

rounded and long; snout length greater than mouth 

width. Keels on each side of caudal peduncle. Upper 

teeth serrated and with concave margin. Dental formula: 14–0 or 1–14/ 13 to 15–1 to 4–13 to 15 (Bigelow 

and Schroeder, 1948); tooth redrawn from Compagno 

(1984). Body blue dorsally, brilliant blue along sides 

and white below (coloration fades after death). Maximum size; 341.5 cm TL (Pratt, 1979). Range: from 

the Banks of Newfoundland, Canada (during summer) 

south, including the Gulf of Maine, Bermuda, the Bahamas, Gulf of Mexico, Caribbean, and the north coast 

of South America (Bigelow and Schroeder, 1948; Compagno, 1984). Habitat: typically beyond the continental 

shelf but occasionally found inshore. 

Figure 5 

Blue shark, Prionace glauca. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 11 

Tiger shark, Galeocerdo cuvier (Fig. 6) 

Interdorsal ridge present. First dorsal fin origin over 

pectoral fin inner corner. Snout broadly rounded; 

length less than mouth width. Upper labial furrows 

long and terminate underneath eyes (McEachran and 

Fechhelm, 1998). Caudal keels on each side of caudal 

peduncle. Small spiracles posterior to eyes. Upper lobe 

of caudal fin elongate with pointed apex. Upper and 

lower teeth broad and serrated with hooked cusps. 

Dental formula: 9 to 11–1–9 to 12/ 9 to 12–1–9 to 12 

(Bigelow and Schroeder, 1948); tooth redrawn from 

Compagno (1984). Body gray or gray brown above and 

yellowish or white below. Dark gray or brown spots 

form blotches and irregular vertical or oblique bars 

along body, dorsal fins, and upper caudal fin lobe; 

markings more distinct in young and faded or absent 

in adults. Neonates and juveniles can have white-tipped 

first dorsal fin. Maximum size: 550.0 cm TL (Bigelow 

and Schroeder, 1948); 410.0 cm TL (Branstetter, 1981); 

287.0 cm TL (fork length converted to TL with conversion from Kohler et al., 1996) and 416.8 cm TL 

estimated (NMFS, n = 154). Range: from Massachusetts south, including Bermuda, the Bahamas, Gulf of 

Mexico, and Caribbean (Bigelow and Schroeder, 1948). 

Habitat: coastal to outer continental shelf; estuaries, 

bays, coral atolls, island passes, and depths to 140 m, 

occasionally oceanic (Compagno, 1984). 

Figure 6 

Tiger shark, Galeocerdo cuvier. 
12 NOAA Technical Report NMFS 153 

Lemon shark, Negaprion brevirostris (Fig. 7) 

No interdorsal ridge. First dorsal fin origin over or posterior to pectoral fin inner corner. Second dorsal fin 

almost as large as first dorsal fin; anal fin almost as 

large as pelvic fins. Snout bluntly rounded; snout length 

less than mouth width. Compagno (1988) reported two 

specimens with very small spiracles .08 of eye length, but 

spiracles are usually absent. Upper teeth with narrow 

smooth cusps and basal serrations. Dental formula: 

15–1 to 3–15/ 13 or 14–3–13 or 14 (Bigelow and Schroeder, 1948); tooth redrawn from Compagno (1984). 

Body gray blue, brown or brownish yellow above and 

yellowish or white below. Maximum size: is 368.0 cm 

TL (Gruber and Stout, 1983); 200.0 cm TL estimated 

(NMFS, n = 2). Range: from New Jersey south, including the Bahamas, Gulf of Mexico, and Caribbean. Habitat: river mouths, estuaries, saline creeks, bays, sounds, 

coral keys; coastal to 92 m depth and occasionally in 

open ocean (Compagno, 1984). 

Figure 7 

Lemon shark, Negaprion brevirostris. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 13 

Brazilian sharpnose shark, 

Rhizoprionodon lalandii (Fig. 8) 

Interdorsal ridge weakly developed or absent. First 

dorsal fin origin over or slightly posterior to pectoral fin 

inner corner. Second dorsal fin origin from over anal 

fin base midpoint to anal fin base termination. Snout 

moderately rounded. Pectoral fins short and broad. 

Well-developed labial furrows. Upper teeth with smooth 

oblique cusps, sometimes with very fine irregular serrations. Dental formula: 12–1–12/11 to 12–12 to 12 

(Springer, 1964); tooth redrawn from Springer (1964). 

Precaudal vertebral centra 79–90, total vertebral centra 

153–168 (Compagno, 1984). Body dark gray or gray 

brown above and light gray below. Maximum size: 

77.0 cm TL (Compagno, 1984). Range: from the Caribbean coast of Panama extending along the north coast 

of South America. Habitat: mud and sand bottoms, 

estuaries and lagoons; coastal in 3 to 70 m depth (Compagno, 1984). The range for the Brazilian sharpnose 

shark overlaps with the Caribbean sharpnose shark. Distinguished from the Caribbean sharpnose shark by the 

number of precaudal and total vertebral centra (Caribbean sharpnose sharks with 66 to 75 precaudal vertebral centra and 136 to 159 total vertebral centra). 

Distinguished from the smalltail shark by possessing 

well-developed labial furrows and teeth with oblique 

cusps. Species account and illustration adapted from 

Meek and Hildebrand, 1923; Springer, 1964; Uyeno 

and Sasaki, 1983; Compagno, 1984. 

Figure 8 

Brazilian sharpnose shark, Rhizoprionodon lalandii. 
14 NOAA Technical Report NMFS 153 

Caribbean sharpnose shark, 

Rhizoprionodon porosus (Fig. 9) 

Interdorsal ridge weakly developed or absent. First 

dorsal fin origin over or slightly posterior to pectoral 

fin inner corner. Second dorsal fin origin from over 

anal fin base midpoint to anal fin base termination. 

Snout moderately rounded. Well-developed labial furrows. Upper teeth with finely serrated oblique cusps. 

Body gray brown or brown above and white below; 

body sometimes with white spots (Compagno, 1984) 

and white fin margins along the rear edge of the first 

dorsal fin and pectoral fins (Guitart, 1974). Dental formula: 11 to 13–1–11 to 13/ 12–12 (Springer, 1964); 

tooth redrawn from Springer (1964). Precaudal vertebral centra 66–75, total vertebral centra 136–159 (Compagno, 1984). Maximum size: 110.0 cm TL (Compagno, 

1984). Range: from the Bahamas south including the 

north coast of Cuba in the Gulf of Mexico, throughout 

the Caribbean, and along the north coast of South 

America. Habitat: coastal to 500 m depth (Compagno, 

1984). Range overlaps with the Atlantic sharpnose shark 

in the Bahamas and along the north coast of Cuba 

(though the distribution of the Atlantic sharpnose shark 

in Cuba is questionable, Guitart-Manday12); range overlaps with the Brazilian sharpnose shark (Rhizoprionodon 

lalandii) from the Caribbean coast of Panama extending along the north coast of South America. Distinguished from the Atlantic sharpnose and the Brazilian 

sharpnose by the number of precaudal and total vertebral centra (Brazilian sharpnose shark with 79 to 90 

precaudal vertebral centra and 153 to 168 total vertebral centra; Atlantic sharpnose shark with 58 to 66 

precaudal vertebral centra and 126 to 144 total vertebral centra; Compagno, 1984). Distinguished from the 

smalltail shark by possessing well-developed labial furrows and weakly serrated teeth with slightly oblique 

cusps. Species account and illustration adapted from 

Springer, 1964; Guitart, 1974; Uyeno and Sasaki, 1983; 

Compagno, 1984. 

12	 Guitart-Manday, D. 1998. Centro de Investigaciones de Marinos, 

Universidad de Habana, Habana, Cuba. Personal commun. 

Figure 9 

Caribbean sharpnose shark, Rhizoprionodon porosus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 15 

Atlantic sharpnose shark, 

Rhizoprionodon terraenovae (Fig. 10) 

Interdorsal ridge usually present; but can be weakly 

developed or absent (Compagno, 1984). First dorsal fin 

origin slightly anterior to over pectoral fin inner corner. 

Second dorsal fin origin from over or anal fin base midpoint to anal fin base termination. Snout moderately or 

sharply rounded. Well-developed labial furrows. Upper 

teeth finely serrated with hooked cusps. Body gray or 

gray brown above and pale gray or white below; frequently with pale or white spots. Pectoral fins often with 

white rear margins. First and second dorsal fins can 

have dusky tips. Dental formula: 11 to 13–1–12 to 13/12 

to 13–12 to 13 (Springer, 1964); tooth redrawn from 

Compagno (1984). Precaudal vertebral centra 58–66, 

total vertebral centra 126–144 (Compagno, 1984). Maximum size: 110.0 cm TL (Branstetter, 1981); 107.0 cm 

TL (Parsons, 1985); 120.0 cm TL (NMFS, n = 1719). 

Range: from New Brunswick, Canada south to the 

north-central coast of Cuba (the distribution of the 

Atlantic sharpnose shark in Cuba is questionable, Guitart-Manday12), including parts of the Bahamas and 

the entire Gulf of Mexico. Habitat: river mouths, estuaries, bays, sounds; coastal to 280 m depth (Compagno, 

1984). Range overlaps with the Caribbean sharpnose 

shark in the Bahamas and along the north coast of 

Cuba. Distinguished from the Caribbean sharpnose 

shark by possessing teeth with hooked cusps and by the 

number of precaudal and total vertebral centra (Caribbean sharpnose shark with 66 to 75 precaudal vertebral 

centra and 136 to 159 total vertebral centra; Compagno, 

1984). Distinguished from the smalltail shark by possessing smooth or weakly serrated teeth with hooked 

cusps and well-developed labial furrows. 

Figure 10 

Atlantic sharpnose shark, Rhizoprionodon terraenovae. 
16 NOAA Technical Report NMFS 153 

Smalltail shark, Carcharhinus porosus (Fig. 11) 

No interdorsal ridge. First dorsal fin origin over pectoral fin inner margin. Second dorsal fin origin from 

over anal fin base midpoint to anal fin base termination. Snout sharply rounded; snout length greater than 

mouth width. Caudal fin length approximately 1/4 of 

the TL. Labial furrows weakly developed, usually not 

visible in profile. Pectoral fins short and broad. Upper 

teeth broad and serrated and with a distinct notch 

along margin. Dental formula: 13 to 15–1 or 2–13 to 

15/ 12 to 15–0 to 2–12 to 15 (Garrick, 1982). Body 

gray or gray blue above and white below. Maximum 

size: 150.0 cm TL (Compagno, 1984); 106.7 cm TL 

(NMFS, n = 1). Range: north central and western Gulf 

of Mexico and western and southern Caribbean. Habitat: coastal to 36 m depth and mud bottoms in proximity of large rivers and estuaries (Springer, 1950; 

Compagno, 1984). Smalltail sharks can be confused 

with Rhizoprionodon species, however, smalltail sharks 

have weakly developed labial furrows and serrated 

teeth; Rhizoprionodon species have well developed labial 

furrows and smooth or weakly serrated teeth (teeth 

with oblique cusps for Brazilian sharpnose sharks and 

Atlantic sharpnose sharks). The second dorsal fin 

origin over or posterior to the anal fin base midpoint 

for smalltail sharks distinguishes smalltail sharks from 

finetooth sharks (Carcharhinus isodon). 

Figure 11 

Smalltail shark, Carcharhinus porosus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 17 

Daggernose shark, 


Isogomphodon oxyrhynchus (Fig. 12)


No interdorsal ridge. First dorsal fin origin anterior to 

pectoral fin axil. Snout appears elongate and flattened 

in profile and sharply triangular from overhead view. 

Broad pectoral fins. Uyeno and Sasaki (1983) reported 

a small spiracle on the left side of the head, but whether 

this is a consistent feature for all daggernose sharks is 

not certain since only one specimen was examined and 

other references do not mention the presence of spiracles. Upper and lower teeth narrow and erect and 

finely serrated. Dental formula: 23–4–22/24–2–23 (Bigelow and Schroeder, 1948); tooth redrawn from Compagno (1984 and 1988). Body gray or gray brown above 

and white below. Maximum size: 152.0 cm TL (Compagno, 1984); 145.0 cm TL (Lessa et al., 1999). Range: 

reported from Trinidad in the southern Caribbean and 

along the north coast of South America to French 

Guiana; also reported from eastern Brazil, Valence, 

Bahia (Compagno, 1984). Habitat: coastal, estuaries, 

river mouths, and rocky bottoms; strong association 

with mud bottoms (Lessa et al., 1999). Species account 

and illustration adapted from Bigelow and Schroeder, 

1948; Uyeno and Sasaki, 1983; Compagno, 1984; Lessa 

et al., 1999. 

Figure 12 

Daggernose shark, Isogomphodon oxyrhynchus. 
18 NOAA Technical Report NMFS 153 

Oceanic whitetip shark, 

Carcharhinus longimanus (Fig 13) 

Interdorsal ridge generally present; sometimes difficult 

to discern or absent (Garrick, 1982). First dorsal fin 

origin over pectoral fin inner margin; sometimes first 

dorsal fin origin is posterior to pectoral fin inner corner 

(Ritter13). Dorsal fin high and apex broadly rounded. 

Pectoral fins long and broad with broadly rounded 

apex. Snout bluntly rounded; length less than or equal 

to mouth width. Upper teeth broad and serrated; lower 

teeth moderately narrow with fine serrations. Dental 

formula: 14 or 15–1 or 2–14 or 15/ 13 to 15–1–13 to 

13	 Ritter, E. 1997. Green Marine, 11517 S.W. 64th St. #A, Miami, FL 

11549. Personal commun. 

15 (Bigelow and Schroeder, 1948; Garrick, 1982). Body 

gray or gray brown above and yellowish or white below. 

Tips of the dorsal fin, pectoral fins, and upper lobe 

of caudal fin are usually white; sometimes fin tips are 

gray (Bigelow and Schroeder, 1948) or not pigmented 

(Castro, 1983). Embryos (Bigelow and Schroeder, 1948) 

and young (Garrick, 1982) can have gray or black tips 

on first and second dorsal fin, pelvic fins, and lower 

caudal fin lobe; the caudal peduncle area can be pigmented dark or dusky (Guitart-Manday12). Maximum 

size; 350.0 cm TL (Bigelow and Schroeder, 1948); 246.0 

cm TL (Backus et al., 1956). Range: from Maine south, 

including the Gulf of Mexico, Caribbean, and the 

north coast of South America. Habitat: oceanic, usually 

beyond the continental shelf; can occur inshore by oceanic islands or in areas with a narrow continental shelf 

(Compagno, 1984). 

Figure 13 

Oceanic whitetip shark, Carcharhinus longimanus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 19 

Bull shark, Carcharhinus leucas (Fig. 14) 

No interdorsal ridge. First dorsal fin origin anterior 

to pectoral fin axil; sometimes first dorsal fin origin is 

over pectoral fin axil (Garrick, 1982; Compagno, 1984). 

First dorsal fin high and triangular. Pectoral fins moderately long and broad. Snout bluntly rounded and short; 

snout length less than mouth width. Body generally 

robust for larger specimens, especially for those greater 

than 150.0 cm TL. Upper teeth broad and serrated. 

Dental formula: 12 to 14–1–12 to 14/ 12 or 13–2–12 or 

13 (Garrick, 1982). Body dark gray or gray above and 

white below. Maximum size: 274.0 cm TL (Springer, 

1950); 268.0 cm TL (Branstetter and Stiles, 1987); 260.0 

cm TL and 298.7 cm TL estimated (NMFS, n = 20). 

Range: from New York south including the Bahamas, 

Gulf of Mexico, and Caribbean. Habitat: coastal, but 

can occur in brackish or fresh water rivers and lakes 

that connect with marine habitats. Distinguished from 

sandbar sharks by lack of an interdorsal ridge. 

Figure 14 

Bull shark, Carcharhinus leucas. 
20 NOAA Technical Report NMFS 153 

Blacknose shark, 


Carcharhinus acronotus (Fig. 15)


No interdorsal ridge. First dorsal fin origin over pectoral fin inner margin; sometimes first dorsal fin origin 

is posterior to pectoral fin inner corner (Bigelow and 

Schroeder, 1948; Castro, 1983). Snout moderately or 

sharply rounded; snout length generally equal to or 

greater than mouth width; Garrick (1982) reports a 

specimen with snout length less than mouth width. Pectoral fins short, often with white rear margin. Upper 

teeth moderately narrow and serrated (serrations often 

difficult to discern for juveniles, Cortes10) with oblique 

cusps and with distinct notch along margin. Dental 

formula: 12 or 13–1 or 2–12 or 13/11 or 12–1–11 or 

12 (Garrick, 1982). Snout tip with dark (juveniles) or 

dusky blotch (adults). Body gray or gray olive above and 

yellowish or white ventrally. Maximum size: 164.0 cm 

TL (Schwartz, 1984); 130.0 cm TL (NMFS, n = 229). 

Range: from North Carolina south, including the Bahamas, Gulf of Mexico, and Caribbean. Habitat: coastal, 

often close to shore. 

Figure 15


Blacknose shark, Carcharhinus acronotus.

Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 21 

Finetooth shark, Carcharhinus isodon (Fig. 16) 

No interdorsal ridge. First dorsal fin origin over pectoral fin inner margin. Snout moderately rounded; length 

less than mouth width. Upper and lower teeth narrow 

and weakly serrated, almost smooth. Pectoral fins short 

and broad. Baughman and Springer (1950) considered 

the long gill slits (twice the length of the eye diameter) 

to be an important distinguishing feature. Dental formula: 13 to 15–1–13 to 15/ 13 to 15–1 to 3–13 to 15 

(Castro, 1983). Tooth redrawn from Garrick (1985). 

Body color is gray or gray blue above and white below, 

can have a dusky band extending posteriorly from pectoral fin; some specimens can have green eyes but this 

may be a localized trait for specimens from the Florida 

panhandle (Carlson14). Maximum size: 160.0 cm TL 

(Castro, 1993); 148.0 cm TL (NMFS, n = 35). Range: 

from New York south to Cuba, including parts of the 

Bahamas and the Gulf of Mexico; in the Caribbean 

along the south coast of Cuba. Habitat: coastal in depths 

as shallow as 4 m (Castro, 1983). Distinguished from the 

smalltail shark by the second dorsal fin origin; second 

dorsal fin origin for the finetooth shark is anterior to 

the anal fin base midpoint; for the smalltail shark the 

second dorsal fin origin is over or posterior to the anal 

fin base midpoint. 

14	 Carlson, J. 2000. NMFS Panama City Laboratory, 3500 Delwood 

Beach Rd., Panama City, FL 32408. Personal commun. 

Figure 16 

Finetooth shark, Carcharhinus isodon. 
22 NOAA Technical Report NMFS 153 

Blacktip shark, Carcharhinus limbatus (Fig. 17) 

No interdorsal ridge. First dorsal fin origin over pectoral fin inner margin. Snout moderately or sharply 

rounded; snout length less than or equal to mouth 

width. Upper and lower teeth narrow, erect and finely 

serrated. Dental formula: 14 or 15–1 to 3–14 or 15/ 13 

to 15–1 or 2–13 to 15 (Bigelow and Schroeder, 1948). 

Body dark gray, gray blue or gray brown above and white 

below. A dark chevron-shaped band originates near the 

pectoral fin and extends posteriorly. First dorsal fin, 

second dorsal fin, pectoral fins, pelvic fins, and lower 

lobe of caudal fin generally with distinct black tips; 

sometimes black tips are faded or nearly obsolete 

for larger specimens, especially on outer surfaces of 

paired fins. Some specimens have circular parasite scars 

located between the first and second dorsal fin. For 

specimens greater than 80 cm TL, the anal fin is pale or 

white (Branstetter, 1982). Maximum size: 202.0 cm TL 

(Castro, 1993); 188.0 cm TL and 200.0 cm TL estimated 

(NMFS, n = 207). Range: from Massachusetts south, 

including the Bahamas, Gulf of Mexico, and Caribbean 

(Garrick, 1982). Habitat: coastal and occasionally offshore; inshore from river mouths, shallow bays, estuaries, island lagoons, and coral reef drop offs (Compagno, 

1984). In the western North Atlantic, the pale or white 

anal fin distinguishes blacktip sharks greater than 80.0 

cm TL from spinner sharks, however, it may be difficult 

to separate specimens of each species when their length 

is less than 80.0 cm TL (Branstetter, 1982). In profile, 

blacktip sharks generally appear more robust between 

the snout and first dorsal fin than spinner sharks. The 

first dorsal fin origin is another distinguishing feature 

that can be useful for separating blacktip sharks from 

spinner sharks; for blacktip sharks the first dorsal fin 

origin is generally over the pectoral fin inner margin, 

for spinner sharks the first dorsal fin origin is generally 

posterior to the pectoral fin inner corner. Branstetter 

(1982) states a useful morphometric feature for separating blacktip and spinner sharks is the comparison of 

the prenare length to the postnare length; for blacktip 

sharks the prenare length is less than or equal to the 

postnare length; for spinner sharks the prenare length 

is greater than the postnare length. 

Figure 17 

Blacktip shark, Carcharhinus limbatus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 23 

Spinner shark, 


Carcharhinus brevipinna (Fig. 18)


No interdorsal ridge. First dorsal fin origin posterior 

to pectoral fin inner corner; sometimes first dorsal fin 

origin is over pectoral fin inner margin (Castro, 1983). 

Snout long and sharply rounded, snout length equal to 

or greater than mouth width. Upper teeth narrow and 

finely serrated, lower teeth smooth. Dental formula: 

16–2 or 3–16/ 15–1 or 3–15 (Garrick, 1982). Body gray 

or gray blue above and white below; often with a dark 

chevron-shaped band originating near the pectoral fin 

and extending posteriorly. Some specimens have circular parasite scars located between the first and second 

dorsal fin. Young under 80.0 cm TL have unmarked fins 

(Branstetter, 1982) or narrow-dark fin margins (Garrick, 1982). Adults with first dorsal, second dorsal, pectoral, anal, and lower lobe of caudal fin black tipped; 

pelvic fins can be black tipped (Garrick, 1982). Sometimes black tips are faded or nearly obsolete for larger 

specimens, especially on outer surfaces of paired fins. 

Maximum size: 244.0 cm TL (Springer, 1960); 208.0 cm 

TL (Branstetter, 1987a); 194.0 cm TL (NMFS, n = 87). 

Range: from North Carolina south to the north coast of 

Cuba, including the Bahamas and Gulf of Mexico. Habitat: coastal to 75 m depth (Compagno, 1984). In the 

western North Atlantic, the black tipped anal fin distinguishes spinner sharks greater than 80.0 cm TL from 

blacktip sharks, however, it may be difficult to separate 

specimens of each species when their length is less 

than 80.0 cm TL (Branstetter, 1982). In profile, spinner sharks generally appear more slender between the 

snout and first dorsal fin than blacktip sharks. The first 

dorsal fin origin is another distinguishing character 

that can be useful for separating spinner sharks from 

blacktip sharks; for spinner sharks the first dorsal fin 

origin is generally posterior to the pectoral fin inner 

corner, for blacktip sharks the first dorsal fin origin is 

over the pectoral fin inner margin. Branstetter (1982) 

states a useful morphometric feature for separating 

spinner and blacktip sharks is the comparison of the 

prenare length to the postnare length; for spinner 

sharks the prenare length is greater than the postnare 

length; for blacktip sharks the prenare length is less 

than or equal to the postnare length. 

Figure 18 

Spinner shark, Carcharhinus brevipinna. 
24 NOAA Technical Report NMFS 153 

Sandbar shark, 


Carcharhinus plumbeus (Fig. 19)


Interdorsal ridge present. First dorsal fin origin slightly 

anterior to or over pectoral fin axil; Garman (1997) 

reports the first dorsal fin origin slightly posterior to 

pectoral fin axil to the midpoint of the pectoral fin 

inner margin. Dorsal fin high and triangular; dorsal 

fin height in adults sometimes more than twice snout 

length (Castro, 1983). Pectoral fins long and broad. 

Snout bluntly rounded, snout length less than mouth 

width. Upper teeth broad and serrated. Dental formula: 

14 to 16–2–14 to 16/ 12 to 15–1–12 to 15 (Bigelow and 

Schroeder, 1948). Body gray, gray blue or gray brown 

above and white below. Maximum size: 243.0 cm TL 

(Springer, 1960); 222.0 cm TL and 243.7 cm TL estimated (NMFS, n = 127). Range: from Massachusetts 

south, including the Bahamas, Gulf of Mexico, and most 

of the Caribbean. Habitat: shallow coastal waters, bays, 

harbors, and estuaries; occasionally to 315 m depth 

(Castro, 1983). Sandbar sharks are distinguished from 

bull sharks by the presence of an interdorsal ridge. 

Even though the dorsal fin origin for sandbar sharks is 

generally anterior to the pectoral fin axil, if the dorsal 

fin origin is over the pectoral fin inner margin, sandbar sharks are grouped with several other similar species (bignose shark, night shark, Galapagos shark, dusky 

shark, and reef shark). Sandbar sharks can be distinguished from similar species by the sandbar shark’s 

high and triangular dorsal fin. 

Figure 19 

Sandbar shark, Carcharhinus plumbeus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 25 

Bignose shark, Carcharhinus altimus (Fig. 20) 

Interdorsal ridge present. First dorsal fin origin over pectoral fin inner margin; sometimes first dorsal fin origin 

is anterior to pectoral fin axil (Castro, 1983; Compagno, 

1984). Snout long and moderately or sharply rounded; 

snout length generally equal to or greater than mouth 

width; Garrick (1982) reports a specimen with the snout 

length less than mouth width. Prominent nasal lobes. 

Pectoral fins long and broad. Upper teeth long, broad 

and serrated. Dental formula: 15–1 or 2–15/14–1–14 

(Springer, 1950, and Hubbel15 from examination of 6 

jaw sets). Body gray above and white below. A green 

sheen is reported (Jensen16) along the gill area in 

freshly captured specimens. Maximum size: 282.0 cm 

TL (Springer, 1950); 162.0 cm TL and 200.0 cm TL estimated (NMFS, n = 3). Range: from Florida south to the 

15 Hubbel, G. 1997. Jaws International, 150 Buttonwood Dr., Key Biscayne, FL 33149. Personal commun. 

16 Jensen, C. 1997. South Atlantic and Gulf of Mexico Fisheries Foundation, 5401 W. Kennedy Blvd., Suite 997, Tampa, FL 33609. Personal commun. 

north coast of South America in the Caribbean, including the Gulf of Mexico; a capture was documented off 

New Jersey (Grace and Henwood, 1997) with identification verified by examination of teeth (Hubbel15). Habitat: outer continental shelf to 423 m depth (Castro, 

1983). The bignose shark shares a number of features 

with the night shark and these two species can be difficult to separate. Both sharks have the dorsal fin origin 

over the pectoral fin inner margin and they have long 

snouts that are moderately or sharply rounded. The 

most useful feature for distinguishing bignose sharks 

from night sharks is teeth; teeth of the bignose shark 

do not have a distinct notch with prominent basal serrations as found in the night shark. Another feature can 

be useful for separating bignose and night sharks: on 

night sharks the second dorsal fin free rear tip is at least 

twice the length of the second dorsal fin height (Garrick, 1985). Garrick (1982) considered the prominent 

nasal lobes (fleshy fold covering a portion of the nostril; also referred to as the anterior nasal flap by Compagno, 1984) and the long, broad, and serrated upper 

teeth on bignose sharks useful features for distinguishing bignose sharks from night sharks, Galapagos sharks, 

dusky sharks, and sandbar sharks. 

Figure 20


Bignose shark, Carcharhinus altimus.

26 NOAA Technical Report NMFS 153 

Night shark, Carcharhinus signatus (Fig. 21) 

Interdorsal ridge present. First dorsal fin origin over 

pectoral fin inner margin; sometimes first dorsal fin 

origin is posterior to pectoral fin inner corner (Castro, 

1983). First dorsal fin low with apex angular or slightly 

rounded. Second dorsal fin free rear tip usually twice 

the length of the second dorsal fin height (Garrick, 

1985). Snout long and sharply rounded; snout length 

equal to or greater than mouth width. Broad upper 

teeth with prominent basal serrations; distinct notch 

along margin and oblique cusps. Dental formula: 15–1 

or 2–15/ 15–1–15 (Bigelow and Schroeder, 1948); tooth 

redrawn from Garrick (1985). Body gray blue above and 

white below; may have scattered dark spots along body 

(Garrick, 1982). The horizontal diameter of the eyes is 

half the length of the first gill slit (Guitart, 1974). Green 

eye color is frequently reported but this is not a consistent distinguishing feature. Maximum size: 276.6 cm TL 

(Bigelow and Schroeder, 1948); 255.0 cm TL (Raschi 

et al., 1982). Range: from Delaware south including 

the Bahamas and the north (Bigelow and Schroeder, 

1948) and south coast of Cuba (Compagno, 1984), and 

parts of the Gulf of Mexico (Boschung, 1979; Branstetter, 1981). Habitat: outer continental shelf and beyond, 

from 50 m to 600 m depth (Compagno, 1984); Bigelow 

and Schroeder (1948) report a specimen from 26 m 

depth; Raschi et al. (1982) summarized the general distribution as between 199 m to 600 m; Branstetter (1981) 

reported a specimen captured with pelagic longline over 

a bottom depth of 2000 m in the northern Gulf of 

Mexico. The night shark can be confused with the bignose shark and it is recommended that teeth be examined; the bignose shark lacks the notched margin and 

prominent basal serrations found on night shark teeth. 

In addition, the night shark has a long second dorsal 

fin free rear tip usually twice the length of the second 

dorsal fin height; the bignose shark does not have a long 

second dorsal free rear tip (Garrick, 1982). Night sharks 

can be confused with silky sharks but the night shark’s 

snout is long and sharply rounded; the silky shark’s 

snout is of moderate length and moderately rounded. 

Teeth of silky sharks do not have prominent basal serrations as is typical for night sharks. Species account and 

illustration adapted from Bigelow and Schroeder, 1948; 

Krumholz, 1957; Guitart, 1974; Branstetter, 1981; Garrick, 1982, 1985; Raschi et al., 1982; Castro, 1983; Compagno, 1984. Some of the information in the species 

account and details used in the illustration were confirmed by examining a night shark specimen collected 

July 2000 from the north-central Gulf of Mexico (81.0 

cm TL male, specimen provided by Cortes10; specimen 

archived by Neer17). 

17	 Neer, J. 2000. Coastal Fisheries Institute, Louisiana State University, 

Baton Rouge, LA 70803-7503. Personal commun. 

Figure 21 

Night shark, Carcharhinus signatus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 27 

Galapagos shark,


Carcharhinus galapagensis (Fig. 22)


Interdorsal ridge present. First dorsal fin origin over 

pectoral fin inner margin; usually closer to pectoral fin 

inner margin midpoint than pectoral fin inner corner. 

Snout bluntly rounded; snout length less than mouth 

width. Upper teeth broad and serrated. Pectoral fins 

broad and long, not distinctly falcate along rear margins. Dental formula: 14–1–14/14–1–14 (Garrick, 1982) 

and upper jaw 15–1–14 (Skomal18). Body color is gray 

brown or brown above and white below. Maximum size: 

292.1 cm TL (Randall, 1963). Range: from Bermuda 

and the Virgin Islands, rare along the U.S. continental 

coast; a capture was reported off of the U.S. eastern 

seaboard (Casey19). Habitat: oceanic islands often in 

areas with rock and coral bottoms, but can cross open 

ocean. Can be confused with the dusky shark and the 

reef shark. Generally, dusky sharks are distributed along 

continental coasts and usually have the first dorsal fin 

origin over or posterior to the pectoral fin inner corner 

and a pectoral fin with a falcate rear margin. The distribution of Galapagos sharks can overlap with the distribution of the reef sharks and it may be necessary to 

examine teeth to make an accurate identification since 

the first dorsal fin origin is similar. Teeth for the Galapagos shark have broader cusps than the more narrow 

cusps on the reef shark. The pectoral fins for the Galapagos shark are long and broad; for the reef shark the 

pectoral fins are long and tapered. Species account and 

illustration adapted from Randall, 1963; Garrick, 1982; 

Castro, 1983; Compagno, 1984. 

18 Skomal, B. 1997. Massachusetts Division of Marine Fisheries, P.O. 

Box 9, Vineyard Haven, MA 02568. Personal commun. 

19 Casey, J. 1985. Cruise results for Polish R/V Wieczno survey of apex 

predators, sharks and swordfish. Narragansett Laboratory cruise 

report, 8 p., 28 Tarzwell Dr., Narragansett, RI 02882-1199. 

Figure 22 

Galapagos shark, Carcharhinus galapagensis. 
28 NOAA Technical Report NMFS 153 

Dusky shark, Carcharhinus obscurus (Fig. 23) 

Interdorsal ridge present. First dorsal fin origin over 

pectoral fin inner margin and generally closer to the 

inner margin corner than the inner margin midpoint; 

sometimes first dorsal fin origin is posterior to pectoral 

fin inner corner (Bigelow and Schroeder, 1948). First 

dorsal fin low and moderately rounded at apex. Pectoral 

fins long and tapered with falcate rear margins. Snout 

bluntly rounded; length generally less than or equal to 

mouth width; Garrick (1982) reports a specimen with 

snout length greater than mouth width. Upper teeth 

broad and serrated. Dental formula: 14 or 15–1 to 3–14 

or 15/ 14–1 to 3–14 (Bigelow and Schroeder, 1948). 

Body gray, gray blue or gray brown above and white 

below. Maximum size: 367.8 cm TL (Springer, 1960; 

measurement converted from fork length with conversion from Kohler et al., 1996); 279.8 cm TL (Natanson, 1995; measurement converted from fork length 

with conversion from Kohler et al., 1996); 330.0 cm TL 

(Kohler et al., 1996); 220.0 cm TL estimated (NMFS, n 

= 4). Range: from George’s Bank, Massachusetts south, 

including the Gulf of Mexico and Caribbean; reports 

of captures from the Bahamas and Bermuda may not 

be accurate (Garrick, 1982). Habitat: along continental coasts and occasionally to 400 m depth (Compagno, 

1984). Dusky sharks can be confused with silky sharks 

(Carcharhinus falciformis), but dusky sharks have pectoral fins with falcate rear margins and teeth without 

distinct notches; silky sharks do not have pectoral fins 

with falcate rear margins and have teeth with distinct 

notches. The reef shark can closely resemble the dusky 

shark and it can be difficult to distinguish the two without examining teeth and pectoral fins; reef sharks have 

moderately narrow teeth and long and tapered pectoral 

fins without falcate rear margins. Dusky sharks can be 

confused with the Galapagos shark because of their similar shaped teeth but Galapagos sharks have long and 

broad pectoral fins without falcate rear margins and are 

typically distributed along oceanic islands. 

Figure 23 

Dusky shark, Carcharhinus obscurus. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 29 

Reef shark, Carcharhinus perezi (Fig. 24) 

Interdorsal ridge present. First dorsal fin origin over 

pectoral fin inner margin. Snout bluntly rounded; 

snout length less than mouth width. Upper teeth moderately narrow and serrated. Long and tapered pectoral fins. Dental formula: 12 or 13–1 or 2–12 or 13/ 11 

or 12–1–11 or 12 (Garrick, 1982). Body gray or gray 

brown above and yellowish or white below. Underside 

of pectoral fin tips, pelvic fins tips, anal fin tip and 

the tip of lower caudal fin lobe often pigmented dusky 

or nearly black. Maximum size: 295.0 cm TL (Garrick, 

1982); 201.0 cm TL (NMFS, n = 3). Range: from Bermuda and Florida south, including the Bahamas, Gulf 

of Mexico, and most of the Caribbean. Habitat: shallow 

coastal waters to 30 m depth, coral reefs and coral reef 

drop offs (Castro, 1983; Compagno, 1984). Can resemble the Galapagos shark and the dusky shark, and it 

may be necessary to examine teeth for an accurate 

identification. Upper teeth for reef sharks are moderately narrow and serrated, for Galapagos and dusky 

sharks upper teeth are broad and serrated. Pectoral 

fins for reef sharks are long and tapered; for Galapagos sharks pectoral fins are long and broad; for dusky 

sharks pectoral fins are long and tapered with falcate 

rear margins. 

Figure 24 

Reef shark, Carcharhinus perezi. 
30 NOAA Technical Report NMFS 153 

Silky shark, Carcharhinus falciformis (Fig. 25) 

Interdorsal ridge present. First dorsal fin origin posterior to pectoral fin inner corner. First dorsal fin low with 

a moderately rounded apex. Second dorsal fin with a 

long free rear tip at least twice as long as second dorsal 

fin height. Pectoral fin length can vary from relatively 

short and broad (especially for specimens less than 1 

m) to long and tapered for larger specimens; Garrick 

et al. (1964) reviews ontogenetic changes in various 

morphometric features. Snout moderately rounded; 

snout length generally less than mouth width; Garrick 

(1982) reports a specimen with snout length greater 

than mouth width. Upper teeth serrated and moderately broad with a notch on each lateral margin; lower 

teeth smooth. Dental formula: 15–2–15/15–1–15 (Garrick, 1982). Body is dark gray or gray brown above and 

white below; often the skin of freshly-caught specimens 

appears to have a silky sheen. Maximum size: 330.0 cm 

TL (Garrick et al., 1964); 267.0 cm TL (Branstetter, 

1987b); 314.0 cm TL (Bonfil et al., 1993); 212.0 cm 

TL (NMFS, n = 38). Range: from Massachusetts south, 

including the Bahamas, Gulf of Mexico, and Caribbean. Habitat: coastal in 18 m depth to open ocean in 

500 m depth, including deepwater reefs (Compagno, 

1984). The teeth notched on each lateral margin, a 

long-tapered pectoral fin without a distinctly falcate 

rear margin, and a moderately rounded snout distinguishes silky sharks from dusky sharks. Unlike night 

sharks, silky sharks do not have an eye diameter one 

half the length of the first gill slit (the silky shark’s eye 

is smaller) and teeth with basal serrations. In addition, 

the night shark’s snout is long and sharply rounded. 

Figure 25 

Silky shark, Carcharhinus falciformis. 
Grace: Field Guide to Requiem Sharks (Elasmobranchiomorphi: Carcharhinidae) of the Western North Atlantic 31 

Acknowledgments 

This guide is as much a new field method for carcharhinid identifications as it is a summary of observations from 

a number of sources. The debt to those whose works for 

Carcharhinidae that preceded this document is respectfully acknowledged. 

Several scientists have contributed valuable advice, information, specimens, photographs, support, or expertise 

needed to complete this guide and their efforts are appreciated. Among these scientists are Joanne LyczkowskiShultz, Scott Nichols, Terry Henwood, Lisa Jones, Perry 

Thompson, David Hanisko, Karen Mitchell, Denise Drass, 

Sally Glynn, and Wil Seidel, NMFS, Mississippi Laboratories; Enric Cortes, John Carlson, Lee Trent, and Mel Miller, NMFS, Panama City Laboratory; Wes Pratt, Lisa Natanson, and Nancy Kohler, NMFS, Narragansett Laboratory; 

Jack Casey, Chuck Stillwell, and Alan Lintala formerly with 

NMFS, Narragansett Laboratory; William Richards, Jose 

Castro, and Cheryl Brown, NMFS, Miami Laboratory; Liz 

Scott Denton and David LeDeaux, NMFS, Galveston, Texas; Brent Winner, Florida Department of Environmental 

Protection, St. Petersburg, Florida; Ash Bullard, University 

of Southern Mississippi-GCRL, Ocean Springs, Mississippi; George Benz, Chattanooga Aquarium, Chattanooga, 

Tennessee; Dario Guitart-Manday, University of Habana, 

Habana, Cuba; Leonel Espinosa, Centro de Investagaciones Pesqueras, Habana, Cuba; Leonardo Castillo and Alejandro Cid del Prado, Instituto Nacional de la Pesca, Mexico City, Mexico; Greg Skomal, Massachusetts Division 

of Marine Fisheries; Erich Ritter, Green Marine, Miami, 

Florida; Phil Heemstra, JLB Smith Institute of Ichthyology, Grahamstown, South Africa; Steve Branstetter, NMFS 

Southeast Regional Office, St. Petersburg, Florida; Captain Jimmy Reahard, Pascagoula, MS; Chris Jensen, Gulf 

and South Atlantic Fisheries Development Foundation, 

Tampa, Florida; Gordon Hubbel, Jaws International, Key 

Biscayne, Florida; Terry Cody and Paul Choucair, Texas 

Parks and Wildlife, Rockport, Texas; Charles Manire and 

John Tyminski, Mote Marine Laboratory, Sarasota, Florida; Trey Driggers, Univ. of South Carolina, Columbia, 

South Carolina. Special thanks are extended to my family, Suzanne Grace, Erin Grace, and Kyla Grace; the command and crew of NOAA Ships Oregon II, Chapman, Relentless (renamed the Gordon Gunter), Ferrel, Delaware II, NMFS 

RV Caretta; UNOLS RV Pelican; commercial fishing vessels 

Captain Grumpy, Persistence, and Old Colony; Japanese fishing vessel Nisshin Maru No. 201. 

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