DESCRIPTION OF LARVAL AND JUVENILE RED SNAPPER, 

 LUTJANUS CAMPECHANUS^ 



L. Alan Collins, John H. Finucane, and Lyman E. Barger* 



ABSTRACT 



Identification and description of the red snapper, Lutjanus campechanus, family Lutijanidae, were 

 based upon the general morphology, meristic characters, head spination, and pigmentation of 18 larval 

 and 6 juvenile specimens, 4.0-22.4 mm standard length. These 24 specimens were selected from a total 

 of 226 larval and juvenile L. campechanus which were collected mainly along the Texas coast from 1975 

 to 1977 . Lutjanids <4.0 mm lacked presently recognizable characters that are diagnostic at the species 

 level. The key to the development of the series was a unique meristic count. Some other useful 

 diagnostic characters were: small serrations on the anterior margin of the pelvic spine in specimens of 

 4.8-12.4 mm, and a long unbroken soft ray immediately adjacent to the pelvic spine in specimens of 

 4.8-10.6 mm. A brief comparison was made between L. campechanus and other lutjanid larvae and 

 juveniles. 



The red snapper, Lutjanus campechanus (Poey), 

 family Lutjanidae, is one of the most important 

 commercial and recreational fish species in the 

 Gulf of Mexico (Bradley and Bryan 1975; 

 Beaumariage and Bullock 1976). Numerous 

 biological and fisheries publications concern the 

 adult of this species. Apparantly only one short 

 publication has dealt with the early life history of 

 L. campechanus however. Arnold et al. (1978) de- 

 scribed the spawning of this species in captivity. 

 The primary purpose of the present paper is to 

 describe the larval and juvenile development of 

 L. campechanus. 



METHODS 



A total of 226 larvae and juveniles (4.0-22.4 mm 

 SL, standard length) of the species were captured 

 by four different methods, which are listed in 

 Table 1. The bongo and neuston net sampling was 

 done according to Marine Resources Monitoring, 

 Assessment and Prediction specifications (Jossi et 

 al. 1975) and was made at a vessel speed of 2.8 

 km/h (1.5 kn). 



The largest specimen was preserved in 40% 

 isopropyl alcohol. Other larvae and juveniles were 

 preserved in buffered 5% Formalin.^ Some larval 



'Contribution No. 79-32PC, Southeast Fisheries Center 

 Panama City Laboratory, National Marine Fisheries Service, 

 NOAA. 



^Southeast Fisheries Center Panama City Laboratory, Na- 

 tional Marine Fisheries Service, NOAA, 3500 Delwood Beach 

 Road, Panama City, FL 32407. 



^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



and juvenile specimens were stained with 

 alizarin-red to aid in measuring £md in counting 

 body parts. 



A dissecting microscope with an ocular mi- 

 crometer was used to make standard measure- 

 ments (Laroche 1977) on 24 specimens. The level 

 of accuracy for micrometer measurements was 

 0.01 mm for measurements <1 mm and 0.1 mmfor 

 measurements >1 mm. All measurements of body 

 length refer to standard length unless otherwise 

 noted. Standard length was defined as the distance 

 from the tip of the snout to the posterior tip of the 

 notochord (before hypural formation) and the tip 

 of the snout to the posterior margin of the hypurals 

 (after hypural formation posterior to the 

 notochord tip). 



Larvae were defined as individuals which had 

 absorbed the yolk sac but which had not completed 

 differentiation of adult fin spine and ray comple- 

 ments. Juveniles were defined as sexually imma- 

 ture individuals having adult fin complements of 

 spines and rays. 



We used the serial or dynamic method of tracing 

 certain characters back from juvenile to larval 

 specimens (Moser and Ahlstrom 1970). 



IDENTIFICATION 



The genus Lutjanus is the most speciose in the 

 family Lutjanidae. Lutjanus campechanus is 1 of 

 10 species of that genus which occur in U.S. waters 

 <200 m deep (Bailey et al. 1970). Lutjanus cam- 

 pechanus occurs along the continental shelf of the 



Manuscnpt accepted May 1979- 

 FISHERY BULLETIN VOL 77. NO 



965 



