APRIETO: EARLY DEVELOPMENT OF FIVE CARANGID FISHES 



Table 7. — Meristic characters of cleared and stained larvae and juveniles ofDecapterus punctatus. 



Standard 

 length 



Dorsal fin 



Anal fin 



Left 



pectoral 



fin 



Left 



pelvic 



fin 



Primary caudal 

 fin rays 



Dorsal Ventral 



Secondary caudal 

 fin rays 



Dorsal Ventral 



Gill rakers, 

 left first 

 gill arch 



Left pre- 



opercular 



margin 



spines 



11; 6 



II; I. 16 



II; I, 18 



II; I. 19 



I, 21 



11; i. 24 



II; I. 26 



II; I, 31 



II; I, 28 



II; I, 27 



II; I. 29 



II; I, 27 



II; I. 27 



II; I, 27 



II; I, 28 



II; I, 28 



II 



Figure 6. — Distribution and apparent relative abundance of the 

 larvae ofDecapteruspunctatus in the Gulf of Mexico: a compwsite 

 record of occurrences at stations occupied from May to August 

 1972 by the Tursiops, Dan Braman, and Gerda. 



here. They occurred in 18.5% of the net stations 

 and constituted 44.7% of the larval carangids 

 collected. 



Lookdown, Selene vomer (Linnaeus) 

 Figure 7 



Literature 



Larvae of S. vomer are previously undescribed. 

 Fowler (1936) illustrated a 15-mm juvenile and 

 Lutken (1880) a 28-mm juvenile. 



Distinguishing Features 



Larvae of S. vomer have extremely deep and 



trenchant bodies. The advanced development of 

 the dorsal and ventral fins is perhaps the most 

 notable feature of their development; it is the ear- 

 liest observed among carangid larvae. The second 

 and third dorsal spines develop into long filaments 

 often twice the length of the body. The ventral fins 

 are elongated, often extending to the anal fin. The 

 larvae probably attain a maximum length of 12 

 mm before transformation. The biggest larva in 

 the series in 9 mm long (Figure 7F) and the next 

 size, 13.5 mm, (Figure 7G) is a transforming larva 

 hatched from a planktonic egg and reared in an 

 aquarium. The smallest juvenile is 23.9 mm long 

 and has attained most adult features. 



As in most larval carangids, there is a bony crest 

 in the supraoccipital bones, two rows of preopercu- 

 lar spines, and a supraorbital crest. The distance 

 from the snout to the occipitals is long and slopes 

 into an abrupt angle. The first interhemal spine is 

 much enlarged and pressed against an equally 

 enlarged hemal spine. 



Morphology 



The larvae are among the most deep bodied of 

 all larval carangids. Relative body depth in- 

 creases during the larval and early juvenile pe- 

 riods (Table 8). It is 32% at 2.5 mm and increases 

 steadily, attaining a maximum of 96% at 23.9 mm. 

 Thereafter, body depth gradually declines but is 

 never less than 74% of the body length in the 

 juveniles. Simultaneous with the deepening of the 

 body is the enlargement of the first interhemal 

 and hemal spine of the first caudal vertebra. The 



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