FISHERY BULLETIN: VOL. 78, NO. 1 



tal shelf waters were initially fixed by immersing 

 net cod ends in 8% formaldehyde for 2 min im- 

 mediately following net washdown. 



Measurements were made on the left side of the 

 body, by ocular micrometer on a dissecting micro- 

 scope. All measurements were made along or per- 

 pendicular to the body midline. Measurements are 

 defined as follows: 



Notochord length (NL) — symphysis of upper 

 jaw to tip of notochord (measured in preflexion 

 larvae). 



Standard length (SL) — symphysis of upper jaw 

 to posterior edge of hypurals (measured in larvae 

 undergoing notochord flexion and in postflexion 

 larvae). 



Snout length — symphysis of upper jaw to an- 

 terior margin of eye. 



Eye diameter — horizontal diameter of eye. 



Head length — symphysis of upper jaw to pos- 

 terior margin of opercular membrane. 



Preanus length — symphysis of upper jaw to 

 posterior margin of anus. 



Snout to origin of spinous dorsal fin — sym- 

 physis of upper jaw to anterior margin of first 

 developed dorsal spine base. 



Snout to origin of soft dorsal fin — symphysis of 

 upper jaw to anterior margin of first developed 

 dorsal ray base. 



Snout to dorsal fin termination — symphysis of 

 upper jaw to posterior margin of last developed 

 dorsal ray base. 



Snout to anal fin origin — symphysis of upper 

 jaw to anterior margin of first developed anal ele- 

 ment base. 



Snout to anal fin termination — symphysis of 

 upper jaw to posterior margin of last developed 

 anal ray base. 



Anus to anal fin — posterior margin of anus to 

 first developed anal element base. 



Snout to pelvic fin insertion — symphysis of 

 upper jaw to anterior margin of base of pelvic fin. 



Depth at cleithral symphysis — vertical dis- 

 tance between dorsal margin of body and ventral 

 symphysis of cleithra. 



Depth at caudal peduncle — least vertical dis- 

 tance between dorsal and ventral margins of body 

 in the area posterior to the terminal dorsal and 

 anal fin rays and anterior to the hypural bones. 



Fin counts include all elements of which any 

 part (including pterygiophore) was developed. 

 Counts were made in unstained specimens since 



the primary purpose of the study was to permit 

 identification of specimens from field collections. 

 Unless otherwise stated, lengths referred to in this 

 paper are standard lengths. 



Data on occurrences of larval Larimus fasciatus 

 in plankton tows from continental shelf waters 

 between Martha's Vineyard, Mass., and Palm 

 Beach, Fla., were provided by Peter Berrien 

 (Fisheries Biologist, Northeast Fisheries Center 

 Sandy Hook Laboratory, National Marine 

 Fisheries Service, NOAA, Highlands, NJ 07732). 

 Collection methods and station distribution are 

 given in Clark et al. (1969, 1970). 



RESULTS 



Bairdiella chrysoura 



Morphology. Body proportions change gradually 

 during larval development (Table 3). Body depth 

 at the cleithral symphysis increases slightly with 

 growth and is >30% SL in all specimens 

 examined. Caudal peduncle depth remains con- 

 stant through development. Preanus length in- 

 creases from 40-45% SL in preflexion and flexion 

 larvae to >50% SL at ^5.7 mm. Positions of the 

 dorsal, anal, and pelvic fins remain quite constant 

 as the fins develop, whereas the decrease in length 

 of the anus-anal fin gap corresponds to the in- 

 crease in preanus length. Snout length and eye 

 diameter change little during development, 

 whereas head length increases from 27-31% NL or 

 SL in preflexion and flexion larvae to 35% SL in 

 larvae 4.9 mm. 



Lateral and marginal preopercular spines are 

 present throughout the series, becoming more 

 numerous with growth until a maximum of five 

 lateral and four marginal spines are present at 

 7.0-8.8 mm. A single posttemporal spine is present 

 at 5.0-7.7 mm, and two such spines are present at 

 8.8 mm. 



Fin development. The pectoral fin is present in 

 all specimens examined; ray development begins 

 at 5.7 mm and 16 rays are present by 8.8 mm 

 (Table 4). Notochord flexion occurs at 4.1-4.4 mm 

 SL. Development of caudal rays begins at the same 

 time as notochord flexion. The full complement of 

 principal rays is developed soon after completion 

 of notochord flexion. Procurrent caudal rays begin 

 to form at 5.7 mm and an incomplete procurrent 

 ray count is present at 8.8 mm. The soft dorsal and 

 anal fins begin ray development at the start of 



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