APRIETO; EARLY DEVELOPMENT OF FIVE CARANGID FISHES 



Table 11. — Meristic characters of cleared and stained larvae and juveniles of OUgoplites saurus. 



The dorsal and anal fin rays differentiate simul- 

 taneously in an anteroposterior direction. Unlike 

 previously described species, in which either the 

 middle or anterior spines are longer, the posterior 

 spine of the first dorsal fin is slightly longer than 

 the rest. The full complement of 6 spines and 19 to 

 21 rays is present at 10 mm. The anal fin rays of 3 

 spines and 18 to 20 soft rays are also complete at 

 10 mm. 



Caudal fin formation is similar to that of the 

 other species described. The full complement of 9 

 to 10 dorsal and 8 to 10 ventral principal rays and 

 18 to 20 secondaries is present at 10 mm. 



Distribution and Spawning 



Adults of O. saurus are known from both coasts 

 of Central America and in the West Indies (Jordan 

 and Evermann, 1896). They also occur along the 

 Atlantic coast of the United States from Mas- 

 sachusetts to Florida and in the Gulf of Mexico 

 (Ginsburg, 1952). The wild larvae and juveniles in 

 the present work were taken from Escambia Bay, 

 Fla., and at Sapelo and St. Simons Islands, Ga., in 

 May and July by means of channel nets and beach 

 seines. The laboratory-reared larvae were 

 hatched from planktonic eggs collected from Bis- 

 cayne Bay. Larvae and juveniles were not col- 

 lected in any of the net stations in the Gulf of 

 Mexico and the south Atlantic coast. Distribution 

 of the young in these regions is obscure, and abun- 

 dance and frequency of occurrence in relation to 

 the other larval carangids could not be estab- 

 lished. The wild larvae obtained were too few to 

 derive conclusive information, but apparently 

 spawning occurs in summer. Unlike the other 



carangids which spawn in offshore pelagic waters, 

 O. saurus spawns in inshore and shallow waters. 

 Further investigation is necessary to establish 

 with certainty the spawning period and sites and 

 the distribution of the young. 



Laboratory Rearing 



Planktonic eggs of O. saurus were collected in a 

 1-m, 505-;u mesh plankton net at the pier of the 

 Rosenstiel School of Marine and Atomospheric 

 Science on 15 July 1972, at 9:00 A.M., EDT. A 

 total of 75 eggs was sorted from the plankton and 

 incubated in a 50-liter glass aquarium. The 

 aquarium water was drawn from Biscayne Bay 

 through the School's seawater system. It was oxy- 

 genated and circulated with compressed air 

 added through airstones and lighted continuously 

 by two cool, white, fluorescent bulbs. Temperature 

 ranged from 23.9" to 28'C and salinity from 32 to 

 36 %o during the experiment. The larvae were fed 

 wild plankton collected from Biscayne Bay as well 

 as nauplii of brine shrimp {Artemia salina). A 

 detailed description of the rearing technique em- 

 ployed is given in Houde and Palko (1970). 



The eggs began hatching in the afternoon of the 

 day of collection and after 24 h all the eggs were 

 presumed hatched. The larvae averaged 1.92 mm 

 at hatching, were 5.2 mm 8 days after hatching, 

 and about 21 mm at 34 days (Figure 9). Mortality 

 in the first 18 days included 2 eggs and 16 larvae 

 preserved for describing larval development. Six 

 young juveniles averaged 25 mm after 45 days. 

 Thereafter, the juveniles failed to feed and all but 

 one died at 51 days when the rearing experiment 

 was terminated. 



439 



