LAROCHE ET AL.: CARANGIDAE 



519 



Table 126. Extended. 



Dorsal, anal, preanal. and caudal finfolds are present at hatch- 

 ing. Yolk-sac larvae rapidly develop the pectoral fin base and 

 finfold. The sequence of fin formation in most species is: caudal, 

 pectoral, anal and soft dorsal, spinous dorsal, and pelvic. Species 

 oi Alectis (Fig. 271 A) and Selene (Fig. 274A) are exceptions, 

 developing pelvic and/or dorsal fin elements precociously before 

 the notochord begins to flex. The sequence of fin formation in 

 these taxa is: either pelvic, spinous or soft dorsal followed by 

 caudal, anal, and pectoral (Aprieto, 1974; Laroche el al., MS). 



Spinous dorsal, soft dorsal, and anal fins generally develop 

 from anterior to posterior, although the first element in each fin 

 may lag, and the most posterior element in the soft dorsal and 

 anal fins may develop precociously in some species, i.e., De- 

 capterus spp. and Selar crumenophthabnus (Laroche et al., MS) 

 (Fig. 270B, C). In many species at least some dorsal and anal 

 fin spines ossify from the distal tip proximally (Fig. 27 IC, 272C) 

 which may be an unusual condition among marine fish larvae 

 and may help characterize the Carangidae. This condition has 

 been noted in a number of species and may occur in most or 

 all species, however, lack of specimens in the critical stage when 

 this condition is recognizable does not yet permit documenta- 

 tion of its occurrence. Pectoral fin elements develop from dorsal 



to ventral. The pelvic spine develops before the rays, and ray 

 formation proceeds away from the spine. 



The separation of the two anteriormost anal fin spines from 

 the third spine by a distinct gap is an important characteristic 

 of most young carangids once fins have formed. This gap is 

 caused by anterior and posterior extensions of the distal part of 

 the pterygiophores supporting the second (ultimate) and third 

 (penultimate) anal fin spines. This gap, although present, is rel- 

 atively narrow in Elagatis bipinrndala and Seriolina nigrofas- 

 ciata, which differ from other carangids in having only two anal 

 fin spines. The only other family known to have young with a 

 similar gap is the Pomatomidae (Laroche et al., MS). 



Development of an "antrorse spine" on the anterodorsal mar- 

 gin of the first dorsal fin pterygiophore (Fig. 272A) is another 

 character that is found in most young carangids following fin 

 development and is shared by only a few other families, i.e., 

 Ephippidae. This "spine" is usually covered with skin but is 

 visible in larvae and juveniles. 



Scales begin to develop during the transformation stage. Many 

 species of carangids develop modified scales in the form of scutes 

 along the posterior portion of the lateral line. Ossifying scales 

 are usually first visible along the straight part of the lateral line 

 anterior and adjacent to the caudal peduncle, where scutes form. 



