APRIETO: EARLY DEVELOPMENT OF FIVE CARANGID FISHES 



Table 9. — Meristic characters of cleared and stained larvae and juveniles of Selene vomer (Linnaeus). 



Distribution and Spawning 



Adults of Selene vomer have been recorded on 

 both coasts of the United States, from Cape Cod to 

 Brazil and from Lower California to Peru (Jordan 

 and Evermann, 1896). They have also been re- 

 ported from the Gulf of Mexico (Ginsburg, 1952), 

 the Bahamas (Bohlke and Chaplin, 1968), and 

 West Africa (Fowler, 1936). 



Larval and early juveniles of S. vomer were 

 taken in all months except in June, October, and 

 December. The monthly occurrence and distribu- 

 tion of the larvae is a composite of the records of 

 specimens which include those taken from the 

 coastal waters of the eastern tropical Pacific from 

 Baja California to Costa Rica, the Gulf of Mexico, 

 and the tropical Atlantic off Brazil and Liberia 

 (Aprieto, 1973). In the Gulf of Mexico, larvae were 

 abundant mainly in the northeastern offshore 

 waters in August which suggests a short spawn- 

 ing period in that area (Figure 2). The larvae oc- 

 curred in 2.2% of the net stations and constituted 

 2.6% of the larval carangids collected in the Gulf 

 of Mexico and the south Atlantic coast. 



Leatherjacket, Oligoplites saurus 

 (Bloch and Schneider) 



Figure 8 

 Literature 



Larvae of this species have not been described 

 previously. 



Distinguishing Features 



Larvae of O. saurus resemble those ofElagatis 

 bipinnulata and Seriola zonata. Further, as in 



E. bipinnulata, the first interhemal spine is thick- 

 ened and, as in-S. zonata, the supraoccipital crest 

 is lacking. Larvae of O. saurus are distinct from 

 those of the two species mentioned in having an 

 orbital crest with fine serrations, 1 to 3 denticles 

 which appear early in the larval period on the 

 dorsal side of the longest preopercular spine, and 

 26 vertebrae — the highest vertebral count among 

 carangids. The number of dorsal spines and pec- 

 toral fin rays formed is fewer than in most caran- 

 gids, 5 to 6 and 15 to 17 respectively. Larval pig- 

 mentation is moderately profuse and, as in most 

 carangid larvae, conspicuous melanophores are 

 present along the bases of the dorsal and anal fins, 

 on the lateral midhne, and on the dorsal wall of 

 the abdominal cavity. The larvae transform at 7 to 

 10 mm. 



The Embryo 



Two preserved eggs of O. saurus are 0.87 and 

 0.88 mm in diameter. They have ventral, single oil 

 globules, 0.33 and 0.34 mm in diameter. The oil 

 globule consists of minute oil droplets and is en- 

 closed in a rather tough, pigmented capsule. The 

 pigmented yolk is bright yellow and unseg- 

 mented. The perivitelline space is narrow and the 

 egg case smooth. The embryos are well developed 

 and have stellate melanophores along the back 

 and upper sides of the body. A large melanophore 

 is present at the posteroventral midline (Figure 

 8A). 



Morphology 



The larvae are 1.87 and 1.97 mm at hatching. 



435 



