FISHERY BULLETIN: VOL. 70, NO. 1 



complete series of egg and larval development 

 of this species. In addition to the reared spec- 

 imens, some postlarvae and juveniles of S. bore- 

 alis -were collected in nets, helping to extend the 

 series beyond the lengths of the longest speci- 

 mens reared in the laboratory. 



MATERIALS AND METHODS 



REARING TECHNIQUES 



Pelagic eggs of S. borealis were collected in 

 a 1-m, 505-/U, mesh plankton net at the sea surface 

 in the Florida Current, about 8 km east of Miami 

 Beach on December 11, 1969, at 10:00 AM EST. 

 Surface temperature was 23.6° C at time of col- 

 lection. A total of 78 eggs were isolated from 

 the catch. They were incubated and the larvae 

 reared in a 55-liter aquarium. Temperature 

 ranged from 23.2° to 24.5° C and salinity from 

 38.0 to 34.6/^r during the experiment. Larvae 

 were fed zooplankton collected from Biscayne 

 Bay and nauplii of brine shrimp {Artemia s'a- 

 lina) . Some pelagic fish eggs were added to 

 the rearing tank beginning the 7th day after 

 hatching to provide newly hatched fish larvae 

 as a food source for the sennets. Constant illu- 

 mination was provided to allow the larvae to 

 feed continuously, both by day and night. Many 

 details of methods used to rear fish larvae were 

 described by Houde and Palko (1970). 



PRESERVATION OF LARVAE 



Only a small series of eggs and larvae were 

 obtained during development because of the 

 small number (78) of eggs available. Two eggs 

 and 18 larvae were preserved in 5% buffered 

 Formalin during the 23 days of the rearing ex- 

 periment. 



WILD-CAUGHT POSTLARVAE 

 AND JUVENILES 



Plankton collections in the Florida Current 

 near Miami Beach between January 13 and Jan- 

 uary 27, 1970, provided 10 postlarval and young 

 juvenile specimens of S. borealis from 7.4 to 30.6 



mm SL. In addition, two juveniles, 59.6 and 

 62.9 mm SL, were collected from Biscayne Bay 

 in a 20- ft beach seine in January 1970, These 

 wild-caught specimens provided data to extend 

 the descriptive series and helped to validate the 

 identification of the laboratory-reared larvae as 

 S. borealis. 



MERISTICS AND MORPHOMETRICS 



Fin rays and spines were enumerated for each 

 of the fins. Myomeres (preanal plus postanal) 

 were counted on each larva when they could be 

 distinguished. 



The following measurements were made: 



Total length (TL) : tip of snout to tip of caudal 

 fin. 



Standard length (SL) : tip of snout to tip of 

 notochord or, in more developed larvae, to 

 base of caudal rays. 



Body depth: height of body, exclusive of fin- 

 fold, at base of pectoral fin. 



Head length: tip of snout to posterior margin 

 of otic capsules in yolk-sac larvae and tip of 

 snout to opercular margin in postlarvae. 



Snout length: tip of snout to anterior margin 

 of the fleshy orbit. 



Preanal length: tip of snout along midline 

 to vertical from anus. 



Eye diameter: horizontal distance from an- 

 terior to posterior margin of the fleshy orbit. 



Tip of lower jaw: length of fleshy extension 

 on tip of lower jaw. 



1st predorsal length: tip of snout to anterior 

 insertion of spinous dorsal fin, measured 

 along the body midline. 



2nd predorsal length: tip of snout to anterior 

 insertion of second dorsal fin, measured 

 along the body midline. 



All counts and measurements were made using 

 a binocular dissecting microscope and ocular 

 micrometer. 



OSTEOLOGY 



Six larvae, 7.4 to 17.0 mm SL, were cleared 

 with trypsin and stained with alizarin (Taylor, 

 1967) to determine the sequence of ossification 

 and to accurately assess the lengths at which fin 



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