NOAA Technical Memorandum NMFS .. F/NEC .. 76 

This TM series is used for documentation and timely communication of preliminary results, 

interim reports, or special purpose information, and has not undergone external scientific 

review, 

Finfish Maturity Sampling 

and Classification Schemes 

Used during Northeast Fisheries Center 

Bottom Trawl Surveys, 1963 ... 89 

Jay Burnett, Loretta O'Brien, Ralph II(. Mayo, 

Jeffrey A. Darde, and Margot ~ohan 

Woods Hole Lab., National Marine Fisheries Serv., wqods Hole, MA 02543 

U. S. DEPARTMENT OF COMMERCE 

Robert A. Mosbacher, Secretary 

National Oceanic and Atmospheric Administration 

John A. Knauss, Administrator 

National Marine Fisheries Service 

James E. Douglas, Jr., Acting Assistant Administrator for Fisheries 

Northeast Fisheries Center 

Woods Hole, Massachusetts 

December 1989 
Page iii 

TABLE OF CONTENTS 

Abstract .......................................................................................................................................................... 1 

Introduction .. ................ .......... ............ .... ................... ...... ............. .......... .... ...... ............ ...................... ............ 1 

Background on Original Criteria .................................................................................................................... 1 

Evolution of Maturity Sampling .................................................................................................................... 1 

Acknowledgements ........................................................................................................................................ 9 

References Cited ............................................................................................................................................ 9 

Appendix: Instructions for At-Sea Maturity Sampling Contained in Photo 

Manual Prepared by Livingstone .................................................................................................... 14 

LIST OF TABLES 

Table 1. Seven-stage Hjort gonad maturity scale developed for Atlantic herring and used 

during early phases of NEFC bottom trawl survey program .................................................. ; ....... 2 

Table 2. Eight-stage FAO maturity classification scheme .......................................................................... 2 

Table 3A. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 

19708 for yellowtail flounder, Limanda ferruginea ........................................................................ 4 

Table 3B. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 

1970s for Atlantic herring, Clupea harengus ................................................................................ 4 

Table 3C. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 

19708 for Atlantic mackere\, Scomber scombrus ............................................................................ 5 

Table 3D. Maturity stages derived by yvoods Hole Laboratory Age and Growth Unit in early 

19708 for silver hake, Mer111cci~1-S bilinearis ........ ..................... .................... ..................... ............ 5 

Table 4. Maturity staging criteria,deveJoped by Livingstone and Halliday and used during 

NEFC bottom trawl surfeys, 1970-76 .......................................................................................... 6 

Table 5. Five-stage maturity clasSification scheme introduced by Morse in 1977 ...................................... 7 

Table 6. Approximate spawning seasons and lengths at first maturity of 24 finfish species 

derived from literature search and used during 1982-83 surveys .................................................. 8 

Table 7. Description and criteria for maturity stages "Ripe and Running" and "Eyed" 

added to five-stage classification scheme in 1983-84 .................................................................... 8 

Table 8. Approximate spawning seasons and probable maturity stages in spring and autumn 

for 20 finfish species from Georges Bank based on analysis of survey maturity data .................. 10 

Table 9. Approximate spawning seasons and probable maturity stages in spring and autumn 

for 18 finfish species from Gulf of Maine based on analysis of survey maturity data .................. 10 

Table 10. Approximate spawning seasons by region of 42 species of finfish and shellfish 

derived from MARMAP egg and larval data .............................................................................. 11 

Table 11. Current maturity staging criteria used during NEFC bottom trawl surveys ................................ 12 
Page 1 

ABSTRACT 

A variety of maturity stage classification schemes have been employed during the Northeast Fisheries Center (NEFC) bottom trawl survey series. 

A~alyses of re~lI1ting maturil~ data, ~epend, to some extent, upon lIlI, understanding of the differences between these schemes, The NEFC Reproductive 

Biology .w0rkmg Gro~p has l~enb(led the need to documen,t the history of survey maturity sampling and compile this information in a citable report, 

TIlls report provides a bnefbackground of events relatmg to survey maturity sampling and summarizes in tabular form the various classifications 

used d~rin~ 1963.~9, During ,?is ?eriod, ~atu.rity ~mpJing waS exp,anded from,two species 10 more than 30 species, and resulted in perhaps the most 

~tenslve time sene$. of malu~ty mfo~atlon lIl,exlst~n~, Ov~r tbls same penod, macroscopic maturity staging criteria have evolved from generic 

literature-based values 10 detailed, species-specific cntena dcnved from observations of collected data, 

INTRODUCTION 

Fisheries scientists have long recognized the need to 

study reproductive biology in order to depict stock dynamics. One such aspect is the systematic determination of 

gonadal maturity stages; not only must mature individuals 

be distinguished from immature ones, but the progression 

of the various developmental stages must be observed to 

delineate spawning cycles. 

When the Woods Hole Biological Laboratory of the 

Bureau of Commercial Fisheries (BCF, now the National 

Marine Fisheries Service) undertook a bottom trawl survey 

program in 1%3, at-sea collection of maturity information 

was limited to two species. By the early 1980s, maturity 

sampling had been expanded to include 32 species. Over 

this period, the macroscopic criteria employed for maturity 

determinations have undergone substantial evolution and 

refinement which, for the most part, have not been documented adequately. In this report, welprovide the back· 

ground for the original maturity staging..sfheme used by the 

survey program and summarize in tabular form the numerous revisions of these criteria during a 27fyearbottom trawl 

survey time series. All tables are preSented virtually in 

their original form and text; any editorial changes have 

been enclosed in squared brackets. ;-

BACKGROUND ON ORIGINAL 

CRITERIA 

The earliest maturity classification scheme was devised by HJort (1910) based upon gross morphological 

observations of gonads from Atlantic herring (Clupea harengus). The seven-stage "Hjort scale" (Table 1) was 

widely used over the next few decades, and underwent a 

minor modification in 1929 in the form of an eighth stage 

("Resting") proposed by Buckmann (1929). In 1960, the 

United Nations Food and Agriculture Organization (FAO) 

adopted Buckmann's eight-stage scheme (Table 2) for 

inclusion in its series of Manuals in Fisheries Science 

(Kesteven 1960). Although derived specifically for Atlantic herring, these criteria provided at least the framework 

for a standardized approach to the collection of maturity 

observations. 

In February 1958, the BCF staff initiated a monthly 

sampling program for haddock (Melanogrammus aeglefinus) in which standardized tows were taken at a fixed 

station located at 42°15' N latitude by 70·00' W longitude 

(about 15 miles northeast of Provincetown, Massachusetts) 

in depths of 100-120 meters (Bureau of Commercial Fish~ 

cries 1958, 1959). In this project (the so-called "Highlands 

Ground Study"), biological information was collected, 

tagging operations were performed, and 100 haddock from 

each sampling period were retained for laboratory studies 

of liver condition (Bureau of Commercial Fisheries 1959), 

food habits (Wigley and Theroux 1965), and gonad developmental stages (Bureau of Commercial Fisheries 1959). 

During the earlier stages of the NEFC's bottom trawl 

survey program (1963-70), only haddock and yellowtail 

flounder (Limanda Jerruginea) were sampled for age structures and maturity stage data. The maturity classification 

scheme employed during this period was essentially the 

eight-stage scheme recommended by FAO (Kesteven 1960), 

except that specific refinements for haddock were introduced based on results from the Highlands Ground Study 

(R. Livingstone, Jr. personal communication1). Maturity 

observations were limited to those fish sampled for age and 

growth, and maturity stage data were recorded directly 

onto the coin envelopes used to retain age samples. It is 

important to note that the pool of seagoing personnel 

participating on these early research survey cruises was 

small in number, but highly experienced; interpretations of 

maturity stages for the two species over this period were 

probably very consistent. 

EVOLUTION OF MATURITY SAMPLI NG 

1970 .. 76 

By 1970, the need for age-based analytical assessments resulted in the expansion, over several years, of atsea survey sampling of age structures and maturity stages to 

several other species: Atlantic cod (Gadus morhua), pol~ 

lock (Pollachius virens). and red hake (Urophycis chuss) in 

1970; Atlantic mackerel (Scomber scombrus), silver hake 

(Merluccius bilinearis), Atlantic herring, and alewife (Alosa 

pseudoharengus) in 1973; Acadian red fish (Sebastes fasciatus), windowpane (Scophthalmus aqllosus), and summer flounder (Paralichthys dentatus) in 1975; and American plaice (Hippoglossoides platessoides) and winter flounder (Pseudopleuronectes americanus) in 1976. The diffiI R. Livingstone, Jr" c/o National Marine Fisheries Serv., Water St., Woods Hole, MA 02543. 
Page 2 

Table 1. Seven-stage Hjort gonad maturity scale (from Hjort (191O)J developed for Atlantic herring and used during early phases of 

NEFC bottom trawl survey program 

Stage Description and Criteria 

Virgin individuals: very small sexual organs close under vertebral column; ovaries wine-colored, torpedoshaped, about 2-3 em long and 2·3 mm thick; eggs invisible to naked eye; testes whitish or grayish brown, knifeshaped, 2-3 cm long and 2-3 mm broad 

II Maturing virgins or recovering spenls: ovaries somewhat longer than half the length of vent raJ cavity, about 

1 cm diameter; eggs small, but visible to naked eye; milt whitish; [testes] somewhat bloodshot, of same size 

as ovaries, but still thin and knife-shaped 

III Sexual organs more swollen, occupying about half of ventral cavity 

IV Ovaries and testes occupying almost two thirds of ventral cavity; eggs not transparent; milt whitish; swollen 

V Sexual organs filling ventral cavity; ovaries with some large transparent eggs; milt white, not yet running 

VI Roe and milt running (spawning) 

VII Spents: ovaries slack with residual eggs; testes baggy, bloodshot 

Table 2. Eight-stage FAO maturity classification scheme [from Buckmann (1929) in Kesteven (1%0)] 

Stage 

II 

HI 

IV 

V 

VI 

Description and Criteria 

Virgin: very small sexual organs close under vertebral column; testis and ovary transparent, 

colorless to gray; eggs invisible to naked eye 

Maturing virgin and recovering spent: testis and ovary translucent, gray-red; length half, or slightly 

more than half, length of ventral cavity; single eggs can be seen with magnifying glass 

Developing: tcst[ e Js and ovaries opaque, reddish with blood capillaries; occupy about half of ventral 

cavity; eggs visible to eye as whitish granular 

Developed: testis reddish white; no milt drops appear under pressure; ovary orange-reddish; eggs 

clearly discernible, opaque; testis and ovary occupy about two thirds of ventral cavity 

Gravid: sexual organs filling ventral cavity; testis white, drops of milt fall with pressure; eggs completely round, some already translucent and ripe 

Spawning: roe and milt run with slight pressure; most eggs translucent with few opaque eggs left in 

ovary 

VII Spent: not yet fully empty; no opaque eggs left in ovary 

VIII Resting: testis and ovary empty, red; a few eggs in state of reabsorption 

culty of the activity was compounded by the addition of a 

regular spring survey in 1968 and intennittent summer and 

winter surveys. The need for generalized maturity classification criteria which would be applicable over a range of 

species and seasons was very apparent. 

Other important Changes occurred as welL In 1973, the 

International Commission for the Northwest Atlantic Fisheries established catch quotas for several species, which 

necessitated greater stock assessment involvement by the 

United States as well as the addition of several new staff 

members to the Woods Hole Laboratory. These changes, 

coupled with the natural attrition of experienced seagOing 

biologists, led to a decline in survey experience levels and 

further increased the need to: (1) compile and summarize 
maturity staging criteria, (2) provide training in maturity 

determinations, and (3) develop a field guide for shipboard 

use. 

A limi ted effort at broadening criteria was made in the 

early 19708 by the Age and Growth Unit at the Woods Hole 

Laboratory, which generated species-specific staging criteria for yellowtail flounder, Atlantic herring, Atlantic 

mackerel, and silver hake (Tables 3A - 3D; J. Penttila, 

personal communication2). In 1972, the Age and Growth 

Unit introduced age sample envelopes listing the eight 

maturity stages; the recorder would simply circle the appropriate stage during the at-sea processing phase of individual fish observations. Beginning in 1973 and continuing to the present, all Atlantic herring, river herring (alewife and blueback herring, Alosa aestivalis), and Atlantic 

mackerel collected for age sampling were frozen at sea and 

processed (including maturity staging) at the Woods Hole 

Laboratory by Age and Growth Unit personnel. 

A more comprehensive attempt to develop a more 

generalized set of criteria was undertaken by R. Livingstone, Jr., head of the Spawning and Fecundity Studies 

Investigation at the Woods Hole Laboratory. ·From joint 

research conducted during 1969-70, Livingstone and R.G. 

Halliday of the Canadian Department of Fisheries and 

Oceans revised existing survey maturity criteria with particular reference to Atlantic cod and pollock (R. Livingstone, Jr., personal communication3

). Theirrevisions were 

based upon observations made during sprvey cruises conducted by both countries and augmenteJ.;by the systematic 

seasonal sampling of fish landed in the port of Boston, 

Massachusetts. Also, color photograph~;were prepared of 

the various maturity stages for several species, by sex, and 

compiled into a manual for at-sea reference. This manual 

included detailed descriptions of the/maturity stages devised by Livingstone and HallidaytTable 4), as well as 

instructions for at-sea maturity sampling (see Appendix), 

and became part of the survey field reference collection in 

1971. Although the maturity manual was expanded and 

improved over the next few years, the basic criteria remained unchanged until 1977. 

1977-84 

In 1977, responsibility for the collection of maturity 

data aboard survey cruises was transferred from the NEFC's 

Woods Hole Laboratory to its Sandy Hook (New Jersey) 

Laboratory. W. Morse, the principal investigator, simplified the existing eight-stage maturity classification scheme 

to five stages (Table 5); this was achieved by combining 

stages Rl and R2 of Livingstone and Halliday into a new 

"Developing" category and by combining stages RJl SI' 

and S2 into a "Ripe" category. This change went into effect 

for the spring 1977 bottom trawl survey. During this 

Page 3 

period, survey maturity sampling was expanded to include 

a total of 32 species. 

In addition, maturity data for individual fish were 

transcribed from the Age and Growth Unit's age sample 

envelopes onto maturity logs, along with length, sex, 

station, and, during 1980-84, pathology information; these 

data were then entered into a computerized maturity data 

base maintained at the Sandy Hook Laboratory. This data 

base contained maturity information by fish length only, 

since age data were not added to data records. Data audits 

for the years 1977-81 were performed to remove gross 

outliers and to adjust data for small fish identified as mature 

which were discontinuous with the lower end of the mature 

spectrum to the immature category (W. Morse, personal 

communication4

). Maturity ogives for numerous species 

were generated from these data using probit analysis (Morse 

1979). 

In 1982, maturity data collection responsibility reverted to L. 0 'Brien of the Resource Surveys Investigation 

at the Woods Hole Laboratory. Maturity data for the years 

1982-84 were entered and archived by the Sandy Hook 

Laboratory, but not audited as described above. Pre-cruise 

meetings were initiated in 1982 for survey participants 

during which maturity sampling and staging criteria were 

reviewed with the use of color slides. Also in 1982, a 

spawning season chart (based on literature values) summarizing the approximate spawning seasons and sizes at first 

maturity for a variety of species was prepared for at-sea use 

(Table 6). 

In 1983, a sixth maturity stage, "Ripe and Running," 

was added, and in 1984, an "Eyed" stage for viviparous 

female redflSh was introduced; criteria for these stages are 

provided in Table 7. Also in 1984, an instructional video 

was developed highlighting maturity sampling techniques 

which is shown at the beginning of each survey cruise. 

.In 1984, the spawning season chart was revised twice. 

The first revision, used on the 1984 spring bottom trawl 

survey, partitioned existing maturity information into separate charts for Georges Bank and the Gulf of Maine (Tables 

8 and 9) in relation to estimated spawning season peaks. 

The second revision, introduced on the 1984 fall survey, 

was based upon analyses of egg and larval data [first 

presented in Smith (1983) and later destroyed in a fire, but 

subsequently given in Smith (1985)J collected during the 

NEFC's Marine Resources Monitoring, Assessment, and 

Prediction Program (MARMAP) (Table 10). This chart 

remains in use today. 

1985w present 

Beginning in 1985, age and maturity data for all fISh 

were included in master data records prepared by the 

Fishery Biology Investigation (successor to the Age and 

2 J. Penttila, c/o National Marine Fisheries Serv., Water St., Woods Hole, MA 02543. 

3 R. Livingstone, Jr., c/o National Marine Fisheries Serv., Water SI., Woods Hole, MA 02543. 

4 W. Morse, National Marine Fisheries Serv., P.O. Box 428, Highlands, NJ 07732. 
Page 4 

Table 3A. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 19708 for yellowtail flounder, Limancia 

jerruginea (R = ripening, S :; spawning) 

Stage Description and Criteria 

Immature Males: testes very small and undeveloped; pinkish color 

Females: ovary small; light pink jelly 

Resting Males: testes small and fairly hard; pinkish while; no milt 

Females: pink-red jelly (may be slightly granular); ovary larger 

R! Males: some milt beginning to fonn; testes larger, not as hard; white color, or pink and white 

Females: ovary orange-peach color, granular appearance; ovary not fuJI 

Rz Males: good deal of milt present, will flow if pressure applied; testes larger, white, soft (pink edge and white) 

Females: ovary peach color; eggs can be seen; ovary large, but not swollen 

R3 Males: milt flows readily when force applied; testes white and full 

Females: ovary peach color; eggs clearing; ovary very large, full, and swol1en 

SI Males: milt flows with gentle pressure; testes white, large, and very full 

Females: ovary peach color; mostly clear eggs; .eggs flow with pressure; ovary full 

S2 Males: testes emptying somewhat, still white 

Females: ovary peach color; mostly clear eggs; ovary emptying 

Recovering Males: raw, red look to testes; milt present; testes large, empty 

Females: ovary peach color; eggs in jelly; ovary large and deflated 

Table 3B. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 1970s for Atlantic herring, Clupea harellgus 

Stage Description and Criteria 

Immature: testes and ovaries very small, threadlike, 2-3 mm broad; testes grayish white or brownish red; ovaries 

pinkish or wine red; fish length < 21 em 

II Immature fisb tbat will spawn next year: testes and ovaries small, 3-8 mm broad; testes reddish or grayish brownred; ovaries bright reddish COIOf; eggs visible only with microscope 

III Ripening, early stage: testes and ovaries occupy about half of ventral cavity, 1-2 em broad; testes grayish or 

brownish red; ovaries orange-red; eggs small, but visible and granular 

IV Ripening, mid stage: testes and ovaries almost as long as body cavity; testes reddish yellow with blood ves-sels 

clearly visible; ovaries orange-red or pale yellow-red; eggs larger, opaque with only a few clear 

V Ripe: testes and ovaries fill body cavity; milt and eggs do not flow, but can be extruded by pressure; testes yellowish 

white or milk white with no reddish color and blood vessels not visible; ovaries yellowish; eggs large anc! mostly 

clear 

VI Spawning: testes and ovaries ripe and emptying; milt and eggs flow freely; testes white or pale yellowish white 

with no blood vessels visible; ovaries yellowish; eggs large and clear 

VII Spent: testes and ovaries baggy, flabby, and bloodshot; testes empty or with residual milt; ovaries empty or with 

few residual eggs 

VIU Resting: testes and ovaries finn and larger than in Stage II; walls striated with blood vessels prominent; testes 

brownish red; ovaries wine red; eggs not visible to naked eye (Stage VIII to Stage III) 

NOTE: FOlWard tips of testes blunter than ovaries; testes brownish or grayish red, while ovaries pinkish or wine red; testes smooth in appearance, while 

ovaries more wrinkled. 
Page 5 

Table 3C. Maturity stages derived by Woods Hole Laboratory Age and Growth Unit in early 1970s for Atlantic mackerel, Scomber 

scombrus (R ::: ripening, S ::: spawning, Rc::: recovering) 

Stage 

Immature 

Resting 

Description and Criteria 

Males: knife-edge to testes; pink, clear, small 

Females: rounded edge to ovaries; pink, clear, small 

Males: pink, opaque, larger 

Females: pink, opaque, larger 

Males: pink-yellow; some milt 

Females: pink-yellow, granular appearance 

Males: yellow-pink; more milt 

Females: yellow-pink; eggs can be seen quite easily 

Males: yellowish; much milt; will flow with pressure 

Females: yellowish; eggs clearing 

Males: yellow-white; testes full; milt flows with little pressure 

Females: yellowish; ovaries full; most eggs clear 

Males: yellow-white; testes emptying; milt flows with little pressure 

Females: yellowish; ovaries emptying; all eggs clear 

Males: yellowish, bloody appearance; some milt; testes large, but empty 

Females: yellowish, bloody appearance; eggs decomposing; ovaries large, but empty 

Table 3D. Maturity stages derived by Woqas Hole Laboratory Age and Growth Unit in early 1970s for silver hake, Merluccius 

bilinearis (R = ripening, S = spawning, R. =~recovering) 

Stage 

Immature 

Resting 

Description and Criteria 

Males: testes white, small, like a twisted string 

Females: ovaries small, light pinkish white< color, clear; little development of blood vessels 

Males: testes white, larger, twisted with lobes 

Females: ovaries larger, pink jelly, and opaque; some blood vessels 

Males: testes larger than in Resting stage; some milt present; network collecting milt is pink and nollarge 

Females: ovaries peach color. granular; large, but not full; blood vessels developing 

. Males: more milt present; network larger 

Females: ovaries peach color; eggs visible; more blood vessels; ovaries large and full 

Males: testes full; network full of milt 

Females: ovaries peach color; eggs clearing; blood vessels prominent; ovaries Jarge and full 

Males: milt flows with pressure; network and testes full 

Females: mostly clear eggs; eggs flow with pressure; ovaries large and swollen 

Males: testes emptying; network still full of milt 

Females: ovaries emptying; clear eggs; no jelly 

Males: testes raw, red, large with some milt; deflated 

Females: ovaries peach color; eggs in jelly; ovaries large, but deflated; stm many blood vessels present 
Page 6 

Table 4. Maturity staging criteria developed by Livingstone and Halliday (unpublished) and used during NEFC bottom trawl surveys, 

1970-76 

Stage Designation 

Immature 

Ripening 1 

Ripening 2 

RIpening 3 

Spawning 1 

Spawning 2 

Spent-Recovering R. 

Resting R, 

Description and Criteria 

Females 

General: small membrane, thin, translucent; pink to wine colored; eggs not visible to naked eye 

Variations: smaller fish that have actually spawned, generally late in season, and in Recovering 

(RJ or Resting (Rt) condition, but resemble stage I; ovary larger than stage I; membrane opaque 

and purplish to grayish blue, to reddish in late Resting stage; R. stage contains remains of 

unspawned eggs; R, stage usually slightly swollen and jelly-like in center (split open to examine 

interior) 

General: noticeable increase in growth as ovary becomes kidney-shaped organ; membrane with 

blood vessel network, and ovary light yellow to orange in color as yolked eggs, barely visible to 

eye, begin development prior to spawning 

Variations: during fall and early winter, some large haddock in this condition, but ovary more 

pink to red 

General: continued increase in growth, and ovary may occupy 1/3 to 1/2 ~f body cavity; membrane with developed blood vessel network, and color yellow-orange to pink-salmon; yolked eggs, 

now easily visible, give membrane distinct granular appearance (this is stage to collect for 

fecundity studies) 

Variations: ovary in Atlanlic cod somewhat lighter in color than in haddock (no observations for 

pollock) 

General: continued increase in growth, and ovary may nearly fill body cavity, accounting for 15-

20 % of total body weight; membrane appears speckled- blotched as unequal portions of yolked 

eggs enlarge and become transparent; color highly variable from salmon or light orange to brick 

red; center of ovary may contain liquid and transparent eggs (spawning has not yet started, but cut 

open to make certain) 

Variations: some fish may appear to be stage R2 by outward appearance, but on being split open 

will reveal tapioca- like mass of ripe-transparent and opaque-yolked eggs 

General: liquid state; ovary may fill body cavity; membrane appears thin and blotched due to 

presence of unequal portions of yolked-opaque and transparent eggs; color variable, reddening as 

spawning proceeds; fluid eggs run from vent under slightest pressure 

Variations: as with stage R3

, outward appearance may be deceiving because of large numbers of 

liquid eggs in center; it is essential to split open these questionable examples, especially when 

catches contain individuals in spawning condition 

General: ovary as above, but would appear less than half its fanner size, and somewhat flaccid; 

membrane thin and appearing more purplish; contents mostly liquid ripe eggs (haddock ovary 

weighed 134 g, perhaps reduced in weight by factor of 6 from S1 size) 

Variations: no observations 

General: greatly reduced in size; purplish and baggy; may contain varying amounts of unspawned 

eggs that will be absorbed before next year's spawning 

Variations: small individuals that spawn late in season may have ovary resembling Immature 

stage (see variations for Immature stage); questionable stages should be cut open and scraped with 

knife for evidence that spawning has taken place (a few unspawned eggs should be present) 

General: recycling for next year's spawning has begun; color whitish to grayish blue, but later 

reddening; membrane toughens and ovary appears slightly swollen; interior jelly-like in consistency (eggs not visible), except for occasional globs of degenerating eggs still being absorbed 

Variations: no observations 
Table 4--Continued 

Stage Designation 

Immature 1m 

Ripening 1 

Ripening 2 

Ripening 3 

Spawning 1,2 

Spent-Recovering Ro 

Resting 

Page? 

Description and Criteria 

Males 

General: small, narrow crimped ribbon; colorless to gray; membrane slightly translucent; blood 

capillaries not visible to eye 

Variations: small males may develop prccoci[ous]ly and produce milt from very small testes 

General: growth noticeable, becomes slightly wavy and pink as blood vessel network becomes 

more visible 

General: lobes of testes increase in size and may acquire reddish tinge from continued development of blood vessels; testes may now occupy up to 1/2 of body cavity 

General: testes may fill body cavity or be less enlarged (more variable in males than females); 

lobes become very swollen, losing some redness and often turning white to chalk white; membrane 

weak and yield[sJ milt easily under pressure (e.g., squeezing lobe with thumb and forefinger), but 

questionable whether spawning has begun 

General: testes extremely fragile and liquid; freshly caught specimens may spew milt from vent 

just in process of handling; testes variable in size; membrane chalk white as S I or later dis-coloring 

and reddening around edges as spawning proceeds as 82 

General: testes greatly shrunken, ragged in appearance; Jobes rimmed with brown-red discoloration; small pockets of milt may still remain 

General: continued shrinking in size; lobes small and thin; color yellowish to off-white 

Table 5. Five-stage maturity classific<1l\on scheme introduced by Morse (unpublished) in 1977 [see Morse (1979)] 

Stage Designation 

Immature 

Developing D 

Ripe R 

Spent s 

Resting Rt,T 

Description and Criteria 

Femalfs: small, translucent membrane usually colorless or pink. Gadids: very thin, ribbon-like tissue 

lying,31ong dorsal wall of gut cavity. Flatfish: small translucent organ located at posterior curve of gut 

cav~ty 

Mates: testes colorless to gray, often more opaque than ovaries and appear more flattened 

Females: ovaries opaque and enlarged with blood vessels becoming prominent; small, opaque eggs 

present as ovary develops to occupy 2/3 of ventral cavity. Flatfish: ovary extending posteriorly from 

gut cavity; bright yenow and finn texture 

Males: testes opaque with lobed or wavy appearance; color variable from red or pink to gray or white; 

milt mayor may not be present in small amounts; will occupy up to 1/2 body cavity. Flatfish: appears 

as oval gray to whitish tissue at posterior curve of gut cavity 

Females: this stage is to be used when female is ready to spawn, is spawning, or has not yet completed 

spawning; ovary may fiU body cavity; eggs abundant and visible through ovary wan; a few to many 

transparent eggs may be present; as pari of eggs are spawned, ovary may have bloodshot appearance, 

but eggs still numerous, color variable from bright orange to red. Notc: if eggs run from vent under slight 

pressure to abdomen, designate as RR (Ripe and Running) 

Males: testes large, 2/3 of gut cavity filled, color white or pinkish or edges turning brown; milt present 

when testes squeezed Of cut open 

Females: ovaries flaccid, usually reddish to purple, and sac-like; interior often quite fluid with a few 

translucent eggs present; ovarian wall opaque 

Males: testes reduced in size, very little or no milt present when cut; COIOf gray 10 brown 

Females: ovaries much reduced in size, color purple to pink; interior jelly-like with no eggs visible; 

no prominent blood vessels 

Males: testes small, opaque, and shrunken in appearance; color may be brownish to gray 
PageS 

Table 6. Approximate spawning seasons and lengths (em) at first maturity of 24 finfish species derived from literature search and used 

during 1982-83 surveys 

Species Spawning Season Males Females 

Mean Range Mean Range 

Acadian redfish May-Aug 22 17·32 24 18·29 

Alewife Apr-May 28 24-32 31 2.')-34 

American plaice Mar-May 27 21-38 34 25-45 

Atlantic cod Dec-Apr 54 41-65 50 38-65 

Atlantic herring Aug-Oct 27 23·37 26 23-37 

Atlantic mackerel May-Jun 31 29-35 31 29-34 

Bluefish lun-Aug 40 40 

Butterfish Jun-Aug 12 11-17 13 11-17 

Fourspot flounder Apr-Nov 26 23-30 28 25-31 

Goosefish Jun-Sep 41 31-48 41 37-52 

Haddock Feb-May 42 32-53 43 32-55 

Longhorn SCUlpin Nov-Feb 21 18-26 21 18-26 

Ocean pout Sep-Oct 40 31-46 35 28-45 

Pollock Nov-Feb 52 43-65 49 37-66 

Red hake May-Aug 25 22-33 28 21-39 

Scup May-Jul 15 13-21 15 13-22 

Silver hake May-Oct 25 20-35 27 20-40 

Summer flounder Oct-Apr 25 23-31 28 25-32 

Weakfish May-Jul 28 20-42 30 21-39 

White hake Oct-Apr 43 36-53 48 35-59 

Windowpane May-Aug 19 15-30 22 18-29 

Winter flounder Jan-May 25 20-34 26 19-38 

Witch flounder Mar-Aug 33 26-39 35 28-46 

Yellowtail flounder Mar-Aug 24 21-37 28 22·36 

Table 7. Description and criteria for maturity stages "Ripe and Running" and "Eyed" added to five-stage classification scheme in 1983-

84 

Stage Designation 

Ripe and Running RR,A,U 

Eyed E 

Description and Criteria 

Males: same criteria as Ripe, but milt flows freely from vent with little or no pressure 

on abdomen 

Females: this stage denotes a ripe female with eggs flowing from vent with little or 

no pressure on abdomen 

Female redfish only: ovary large and robust, with transparent membrane, with dark 

spotted eggs which are developing larvae 
Growth Unit). Special projects conducted subsequent to 

1985 have resulted in a much longer time series of maturity 

data for some species. This represents the first time that 

length, age, sex, and maturity information appeared on the 

same data record, a feature which has greatly facilitated 

maturity analyses. 

Starting in autumn 1986 and continuing to the present, 

maturity workshOps have been held after each survey leg in 

which fresh fish captured during the survey are dissected 

and displayed for training and discussion. At the conclusion of the survey season, a voluntary "quiz" is administered to seagoing personnel to help identify problem 

species and maturity stages, and to evaluate the magnitude 

of error inherent within maturity staging data. Additionally, samples are taken for histological analysis in an 

attempt to clarify and improve macroscopic criteria. 

A new initiative to upgrade the photographic field 

guide resulted in the introduction of a simplified, waterproof deck reference in spring 1989. In a special study for 

Atlantic cod during 1987-88, gonad and body weights of 

individual fish were measured at sea to generate gonadosomatic indices. The possibility that such ind.ices might be 

used to audit maturity staging data is currently being 

investigated. 

Based on the ongoing work mentioned above, macroscopic staging criteria have received a new revision (Table 

11), resulting in the most complete and species-specific set 

of criteria to date. These criteria v\:ere first used on the 

autumn 1989 survey, and represel}~ the culmination of 

years of evolution, refinement, and r~vision. 

ACKNOWLEDGEM ENTS 

The NEFC Reproductive ~iblogy Working Group 

would like to thank Donald D. Flescher, Linda I. DespresPatanjo, and Thomas R. Azarovitz of the NEFC's Resource 

Surveys Investigation for their assistance in verifying historical events; Wallace W. Morse of the NEFC's Ichthyoplankton Investigation for verifying the account of his 

role in 1977-84; and Robert Livingstone, Jr., for piecing 

together undocumented events and his thoughtful review of 

this manuscript. 

Pages 

REFERENCES CITED 

Buckmann, A. 1929. Die methodik fischereibioiogischer 

unter-suchungen an meeresfischen. Abderhalden, 

handbuch der biologischen arbeitsmethoden 9 (6,1). Urban und Schwarzenberg, Berlin. 194 pp. 

Bureau of Commercial Fisheries. 1958. Annual report of 

the Woods Hole Laboratory for the year ending June 30, 

1958. Available from National Marine Fisheries Service, Water St., Woods Hole, MA 02543. 78 pp. 

Bureau of Commercial Fisheries. 1959. Annual report of 

the Biological Laboratory, Woods Hole, Mass., for the 

year ending June 30, 1959. Available from National 

Marine Fisheries Service, Water St., Woods Hole, MA 

02543. 52 pp. 

Hjort, J. 1910. Report on herring investigations until 

January 1910. Cons. Perma. Int. ExpZcr. Mer PubL Cire. 

No. 53. 174 pp. 

Kesteven, G.L., ed. 1960. Manual of field methods in 

fisheries biology, proviso ed. FAO Manuals Fish. Sei. 

No. 1. 152 pp. 

Livingstone, R., Jr., and R.G. Halliday. [Undated.] Unpublished table on maturity staging criteria. Available from 

National Marine Fisheries Service, Water St., Woods 

Hole, MA 02543. 

Morse, W.W. 1979. An analysis of maturity observations 

of 12 groundfish species collected from Cape Hatteras, 

North Carolina to Nova Scotia in 1977. Nat. Mar. Fish. 

Serv., Sandy Hook Lab. Rep. No. SHL 79-32. 21 pp. 

Smith, W.G. 1983. Spawning seasons for principal coastal 

species. Nat. Mar. Fish. Serv., Sandy HookLab. Rep. No. 

SHL 83-08. [Unavailable; all copies destroyed by fire.] 

Smith, W.G. 1985. Temporal and spatial spawning patterns of the principal species of fish and invertebrates in 

the Georges Bank region. Nat. Mar. Fish. Serv., Sandy 

Hook Lab. Rep. No. SHL 85-04. 35 pp. 

Wigley, R.L., and R.B. Theroux. 1965. Seasonal food 

habits of Highlands Ground haddock. Trans. Amer. Fish. 

Soc. 94: 243- 251. 
Page 10 

Table 8. Approximate spawning seasons and probable maturity stages in spring and autumn for 20 finfish species from Georges Bank 

based on analysis of survey maturity data 

Species SeaSQn (peak) 

Acadian redfish Apr-Aug (Jun-Jul) 

American plaice Feb-Jun (Apr-May) 

Atlantic cod Nov-May (Feb-Mar) 

Atlantic herring Sep-Dec (Sep-Oct) 

Atlantic mackerel Apr-luI (May-Jun) 

Butterfish Jun-Sep (Jun) 

Fourspot flounder Jun-Aug (Jul-Aug) 

Goosefish Jun-Aug (Jun-Jul) 

Haddock lan-May (Mar-Apr) 

Longhorn sculpin Nov-Feb (Dec-Jan) 

Ocean pout Sep-Oct (Sep) 

Pollock Oct-Mar (Dec-Jan) 

Red hake May-Sep (Jun-Jul) 

Silver hake Apr-Oct (May-Aug) 

Summer flounder Sep-Nov (Oct) 

White hake Oct-May 

Windowpane Jun-Oct (lui-Aug) 

Winter flounder Mar-May (Apr) 

Witch flounder Apr-Aug (May-Jun) 

Yellowtail flounder Apr-Aug (May-Jun) 

I D '" Developing; R '" Ripe; E = Eyed; S '" Spenl; and T '" Resting. 

Approximate Maturity Stage! 

Spring 

D-R-E 

D-R 

SoT 

T 

D-R 

T-D 

T·D 

o 

D-R-S-T 

SoT 

T 

SoT 

T-D 

T-D 

T 

D-R-S-T 

T-D 

D-R-S 

D-R 

T-D 

Autumn 

D·R·S 

T 

T-D-R 

D-R-S 

T 

SoT 

SoT 

SoT 

T-D 

T-D 

R-S 

T-D 

SoT 

SoT 

D-R-S 

T-D-R 

R-S-T 

T 

T-D 

SoT 

Table 9. Approximate spawning seasons and proba bJe maturity stages in spring and autumn for 18 finfish species from Gulf of Maine 

based all analysis of survey maturity data 

Spedes Season (peak) 

Acadian redfish Apr-Aug (lun-Jul) 

American plaice Feb-Jull (Apr-May) 

Atlantic cod Nov-May (Mar-May) 

Atlantic herring Aug-Dec (Sep-Oct) 

Atlantic mackerel May-Jul (Jun) 

Butterfish Jun-Sep (lui) 

Goose fish Jun-Sep (Jun-Jul) 

Haddock Feb-May (Mar-Apr) 

Longhorn sculpin Nov-Feb (Dec-Jan) 

Ocean pout Sep-Oct eSep) 

Pollock Oct-Mar (Dec-Jan) 

Red hake May-Sep (Jun-Jtll) 

Silver hake JUIl-Oct (lui-Aug) 

White hake Nov-Apr 

Windowpane JUIl-Oct (luJ-Aug) 

Winter flounder Apr-May (Apr) 

Witch flounder Apr-Aug (May-Jun) 

Yellowtail flounder Apr.Aug (May-Jun) 

D '" Developing; R '" Ripe; E =: Eyed; S =: Spent; and T '" Resting. 

Approximate Maturity Stage! 

Spring 

D-R-E 

D-R 

R-S-T 

T 

D-R 

T-D 

D 

D-R-S-T 

SoT 

T 

SoT 

T-D 

T·D 

R-S·T 

T-D 

D·R·S 

D·R 

T-D 

Autumn 

D-R-S 

T 

T-D-R 

D-R-S 

T 

SoT 

SoT 

T-D 

T·D 

R-S 

T-D 

SoT 

SoT 

T-D-R 

SoT 

T 

T 

T 
Page 11 

Table 10. Approximate spawning seasons (peak in parentheses) by region of 42 species of finfish and shellfish derived from MARMAP 

egg and larval data [from Smith (1983)] 

Boreal (shallow) species 

Atlantic herring 

American plaice 

Atlantic cod 

Pollock 

Haddock 

Boreal (deep) species 

Witch flounder 

Acadian redfish 

Cusk 

Atlantic wolffish 

Atlantic argentine 

Thorny skate 

Warm water species 

Bluefish 

Northern searabin 

Scup 

Longfin squid 

Pourspot flounder 

Summer flounder 

Butterfish 

Eurythermal species 

Ocean pout 

Middle Atlantic 

None reported 

None reported 

Nov-Apr (Mar-Apr) 

Oct-Mar (Dec-Jan) 

None reported 

Apr-Aug (May-Jun) 

None reported 

None reported 

None reported 

None reported 

None reported 

May-Aug (Jul) 

Jun-Oct (Aug-Sep) 

May-Aug (May-Jun) 

Apr-Sep (Jun&Sep) 

May-Sep (Ju/) 

Sep-Dec (Oct-Nov) 

May-Sep (Jun-JuI) 

Southern New England 

Oct-Dec (Oct) 

Peb-Jun (Apr-May) 

Nov-May (Nov-Mar) 

Oct-Mar (Dec-Jan) 

Jan-May (Mar-Apr) 

Apr-Jul (May-Jun) 

Apr-Jul (Apr-May) 

Nov-Jan (peak unknown) 

None reported 

Probably none 

May-Aug (Jul) 

May-Aug (May-Jun) 

Apr-Sep (Jun) 

Jun-Aug (Jul) 

Aug-Nov (Del) 

May-Sep (Jul) 

Georges Bank 

Sep-Dce (Scp-Oet) 

Peb-Jun (Apr-May) 

Nov-May (Feb-Mar) 

Oct-Mar (Dec-Jan) 

Jan-May (Mar-Apr) 

Gulf of Maine 

Aug-Dec (Sep-Oct) 

Peb-Jun (Apr-May) 

Nov-May (Mar-May) 

Oct-Mar (Dec-Jan) 

Pcb-May (Mar-Apr) 

Apr-Aug (May-Jun) Apr-Aug (May-Jun) 

Apr-Aug (Jun-Jul) Apr-Aug (Jun-Jul) 

Apr-Jul (Apr-May) Apr-Jul (Apr-May) 

Nov-Jan (peak unknown) Nov-Jan (peak unknown) 

None reported Mar-May (Mar) 

All year (Apr-Sep) All year (Apr-Sep) 

None reported 

None reported 

None reported 

Apr-Jul (Jun) 

Jun-Aug (luI-Aug) 

Sep-Nov (Oct) 

Jun-Sep (Ju1) 

None reported 

None reported 

None reported 

JuI (JuI) 

None reported 

None reported 

Jun-Sep (Jul) 

None repor~ Sep-De! (Ocl) Sep-Oe! (Oct) 

None reportee Nov-Peb (Dec-Jan) Nov-Feb (Dec-Jan) 

Mar-Aug (Ma)') Apr-Aug (May-Jun) Apr-Aug (May-Jun) 

Mar-May (May) Pcb-May (Feb-Mar) Mar-May (Apr) 

Longhorn sculpin 

Yellowtail flounder 

Winter flounder 

Windowpane 

Little skate 

May-Nov (Ma)l,&Sep) May-Nov (Sep) Jun-Oet (Jul-Aug) 

All year (Nov-jan&Jul) All year (Nov-Jan&Jan-Jul) All year (Nov-Jan&Jul) 

None repbrted All year (Apr-May&Nov-Peb) All year (Apr-May&Nov) 

Sep-Oet (Sep) 

Nov-Pcb (Dec-Jan) 

Apr-Aug (Jun) 

Apr-May (Apr) 

Jun-Oct (Jul-Aug) 

All year (Oct-Jan) 

Winter skate Aug-Nov (Sep) 

Stenothermal species 

Red hake Mar-Oct (Jun-lul) Mar-Dc! (Aug-Sep) May-Sep (Jun-Jul) May-Sep (Jun-Jul) 

Spiny dogfish Nov-Peb (Jan) Nov-Feb (Jan) Sep-May (Jan-Mar) None reported 

Silver hake Apr-Oct (Sep) Apr-Oct (Jun) Apr-Oct (May-Aug) Jun-Oet (Jul-Aug) 

Sea raven None reported Oct-Dec (Nov-Dec) Oct-Dec (Nov) Oct-Dec (Nov) 

Cunner Apr-Oct (Jun) Apr-Oct (Jun) May-Aug (May-Jun) Jun-Sep (Jun) 

American lobster May-Aug (May-Jun) May-Aug (May-Jul) Jun-Aug (lui-Aug) Jul-Aug (Jul-Aug) 

White hake Oct-Apr (Dec-Peb) Oct-Mar (Dec-Pcb) Oct-May (peak unknown) Nov-Apr (peak unknown) 

Goosefish Mar-Aug (May-Jun) Apr-Aug (Jun) Jun-Aug (Jun-Jul) Jun-Sep (Jun-Jul) 

Other species 

Alewife Mar-Apr (Apr) Mar-Apr (Apr) None reported Apr-May (May) 

Blueback herring Apr-Jun (May) Apr-Jun (May) None reported May-Jun (Jun) 

Northern sand lance Nov-Mar (Jan-Peb) Nov-Mar (Jan-Feb) Nov-Mar (Jan-Peb) Dec-Apr (Feb-Mar) 

Atlantic mackerel Apr-Jun (Apr-May) Apr-Jun (May) Apr-Jul (May-Jun) May-Jul (Jun) 

Gulf Stream flounder May-Oct (Jul-Aug) JUn·Oct (Jul-Aug) Jun-Oct (Jul-Aug) None reported 

Atlantic rock crab All year (Apr-Jun) All year (Apr-Jun) 

Jonah crab Jul (Jul) 

Sea scallop Jul-Sep (Aug) Jul-Sep (Aug) Sep-Oct (Sep-Oct) Aug-Oct (Aug-Sep) 

Swordfish None reported None reported None reported None reported 
Page 12 

Table 11. Current maturity staging criteria used during NEFC bottom trawl surveys 

Stage Code 

Immature 

Developing D 

Ripe R 

Eyed E 

Ripe and Running U 

Spent s 

Resting T 

Immature 

Description and Criteria 

Females 

Ovary paired, tube-like organ, small relative to body cavity; thin, transparent outer membrane; 

contains colorless to pink jell-like tissue with no visible eggs 

Butterlisb: ovary paired and flattened, with striations or wrinkles in ovary wall 

Ovaries enlarge to occupy up to 2/3 of body cavity; if blood vessels present, they become 

prominent; ovary has granular appearance as yellow to orange yolked eggs develop 

Enlarged ovaries may fill entire body cavity; mixture of yellow to orange yolked eggs and 

hydrated or "clear" eggs present (50% or more clear eggs denotes ripe ovary, while less than 

50% denotes developing ovary) 

Acadian redfish only: ovary large and robust with transparent membrane and with dark spotted 

eggs which are developing larvae 

Ripe female with eggs flowing from vent with little or no pressure to abdomen 

Ovaries flaccid, sac-like, similar in size to ripe ovary; color red to purple; ovary wall thickening, 

becoming cloudy and translucent vs. transparent as in ripe ovary; some eggs, either clear or 

yolked, may still be present, however most adhere to ovary wall; therefore, CUT QI'EN OVARY 

to make sure there is no mass of eggs in center of ovary (as in stages D and R) 

Gonad reduced in size relative to ripe ovary, but larger than as immature; interior jell-like with 

no visible eggs 

Flounders: ovary does not appear to reduce in size relative to body cav ily as much as in gad ids, 

and interior usually yellow or orange; apparently, eggs spawned and after a short spent stage, 

ovary develops up again with yolked eggs which are small and do not get any larger until prior 

to next spawning season; ovary wall thicker and tougher than ripe ovary wall, and wall is cloudy 

or translucent, rather than clear as in ripe ovary 

Gadids: ovary wall thick and tough with purplish membrane and no prominent blood vessels; 

since there is not a fresh blood supply, vessels more purple than bright red 

Silver hake: exception to abovc, this species more similar to flounders; eggs never seem to 

resorb into a jell-mass, but ovary continues to reduce in size while maintaining yellow-orange 

color of yolked eggs 

Males 

Testes small relative to body cavity, colorless to gray, and translucent 

Butterfish: similar in appearance to ovary, with smooth wall vs. striations in female 

Flounders: testis triangular,loc3ted at posterior edge of gut cavity; other testis in same position 

on opposite side 

Winter flounder: anterior portion similar to other flounders, however posterior portion extends 

back similar to ovary of females; shape of extreme posterior portion of testis different from 

female: instead of coming to a point as in female, endpoint is rounded, and testis more flattened 

than round as it extends posteriorly 

Gadids: testes narrow and elongate with many lobes giving appearance of crimped ribbon 
Table 11.--Continued 

Stage Code 

Developing D 

Ripe R 

Ripe and Running u 

Spent s 

Resting T 

Page 13 

Description and Criteria 

Males 

Atlantic herring, Atlantic mackerel, scup: similar in appearance to ovary, but there is an edge 

to testis vs. being rounded in female 

Testes enlarge and color is gray to off-white; texture of testis is a firm consistency with very 

little or no milt present 

Testes now very large, color chalk white, and consistency mostly liquid; milt will flow easily 

if testis cut 

Gadids: testes will appear to fill entire body cavity 

Before cutting open fish, milt flows easily from vent with little or no pressure on abdomen; once 

cut open, milt flows easily and color is chalk white 

Testes flaccid, not as full of milt and robust as in Ripe stage; may contain residual milt; edges 

or parts of testes starting to turn gray and milt recedes 

Gadids: «dges of lobes reddish to brown, or gray, as milt recedes from edge 

Testes shrunken in size relative to Ripe stage; color yellow, brown, or gray with little or no milt 
Page 14 

APPENDIX: INSTRUCTIONS FOR AT .. SEA MATURITY SAMPLING 

CONTAINED IN PHOTO MANUAL PREPARED BY LIVINGSTONE 

DETERMINING MATURITY STAGE 

Color, size of the gonad in relation to the body cavity, and fish length are the most helpful criteria for identifying 

maturity stages. 

DISTINGUISHING THE IMMATURE FROM THE RESTING STAGE 

After spawning, the gonad shrinks in size so that in all but the older fish one is apt to call the "resting" gonad 

"immature." For haddock, Atlantic cod, and pollock, I have noted the following differences between the two stages: 

1. The resting gonad is slightly larger than the immature gonad, a point obvious in older specimens. 

2. The membrane of the resting ovary is usually opaque; it is translucent in the immature. It is also generally more 

leathery to the touch and in males looks dried up. 

3. If cut open, the resting ovary often contains remains ofunspawned eggs or resorbing eggs (evidence of spawning); 

the immature ovary is jell-like on the inside with no visible eggs except under magnification. 

The resting phase lasts until the gonad is recycled for the next spawning season. Thus, in the autumn, we would expect 

most of the spring spawners to be in this condition. 

RECORDING MATURITY DATA 

Most maturity data are taken at the same time the age and growth samples are being processed. Sex and maturity stage 

are recorded on the scale envelopes. Some of the newer envelopes have maturity stage 'abbreviations printed on them, so 

the recorder simply circles the correct maturity stage. If the person staging the gonads is unsure, then the recorder should 

note the stage with a question mark or some such notation on the envelope. Maturity stages are copied onto maturity stage 

logsheets (provided for each cruise) during times of bad weather and at the discretion of the chief scientist. 

When the species being processed in an age-and-growth sample is required for fecundity, then the recorder should note 

this information on the envelope as FEe-! which would indicate that this was the first sample preserved for fecundity. Age 

data should always be taken with fecundity samples. 

1:< u. S. GOVcRNMEfH PRINTING OFFICE: 1990--500-031--20001