and averages 35% during the late larval and early 

 juvenile stages. The head is as deep as long at 3.8 

 mm and is deeper than long for most of the larval 

 period. Head depth reaches a maximum of 110% of 

 the head length at 5 mm and averages 101% in the 

 late larvae. The dorsal profile of the snout is 

 slightly concave at 3.8 mm; at notochord flexion, it 

 becomes indented at the anterior and posterior 

 margins of the slightly swollen forebrain. These 

 indentations disappear in older larvae and at 

 transformation, the dorsal profile becomes convex. 



The eyes are round and large. Relative eye 

 diameter ranges from 26.3 to 31.3% of the head 

 length. A low orbital crest is formed above the eyes 

 in early larvae but regresses at metamorphosis. 



A supraoccipital crest is present throughout the 

 larval stages. At 15 mm, the crest is much reduced 

 and is no longer visible externally but may be 

 observed in cleared and stained specimens. 



There are two series of preopercular spines: one 

 along the margin and another on the lateral sur- 

 face. Spines on the lower margin are bigger and 

 more serrated than those on the lateral surface. 

 All preopercle spines gradually diminish in size 

 and are completely overgrown by the expanding 

 preopercle bones following metamorphosis. 



The gut is long and coiled in a single, rounded 

 loop in larvae up to a length of 12 mm; at 18 mm, a 

 second loop is added. Hypaxial muscles enclose the 

 gut at 5 mm and completely cover the abdominal 

 cavity except at the opening of the gut at 8 mm. 



The number of myomeres is constant — 10 

 preanal plus 14 postanal — throughout the larval 

 and early juvenile periods. 



The first scales formed are those found along the 

 lateral line near the caudal peduncle. Lateral line 

 scales ossify in a posteroanterior direction at 15 

 mm. Regular body scales are not ossified until the 

 juveniles are at least 20 mm long. 



Pigmentation 



Larvae are among the most intensely pig- 

 mented of carangids. In the early larvae (3.8-4.6 

 mm), the most conspicuous pattern of pigmenta- 

 tion includes melanophores along the bases of the 

 dorsal and anal fins and along the lateral midline 

 (Figure lA, B). Small patches of melanophores are 

 present on the head, jaws, snout, and on the upper 

 sides of the body. Internal pigmentation is concen- 

 trated on the dorsal wall of the peritoneum. At 5 to 

 6 mm, melanophores develop profusely all over 

 the body leaving only a small unpigmented area at 



FISHERY BULLETIN: VOL. 72, NO. 2 



the caudal peduncle (Figure 1C,D). A row of 

 closely spaced pigment cells along the midventral 

 line below the gut is notable and distinguishes 

 early larvae from similarly pigmented larvae of 

 Seriola. Xanthophores (yellow) develop profusely 

 on the head and back in late larvae. At 

 metamorphosis, iridiophores (reflecting), xantho- 

 phores, and melanophores cover the whole length 

 of the body except on the jaws and fins, and an 

 irregular row of large melanophores is formed on 

 the upper side of the body (Figure IE). The 

 melanophores are capable of expansion and con- 

 traction and the larvae are pale or dark depending 

 on the state of the pigment cells. Iridiophores and 

 xanthophores fade upon preservation. The only 

 chroma tophores apparent in preserved specimens 

 are the melanophores. 



Fin Development 



Rudiments of all fins except the ventral fins are 

 present in the smallest larva (3.8 mm) and are 

 situated in about the position they occupy at older 

 stages. The fins ossify in the following sequence: 1) 

 caudal, 2) first dorsal and anal, 3) second dorsal 

 and pectoral, 4) ventral. All fins are essentially 

 complete at metamorphosis (Table 3). 



In the pectoral fins the dorsalmost rays are the 

 first to ossify at 5 mm, and the rest of the rays are 

 added ventrally. The full complement of 18 to 21 

 rays is present at 8 mm. 



The pelvic fins ossify at 6 mm, and the full com- 

 plement of 5 rays is present at 8 mm. The pelvic fin 

 rays grow fast, and at transformation they are 

 about as long as the pectoral fins. 



Ossification of the dorsal and anal fin rays pro- 

 ceed in an anteroposterior direction in an orderly 

 manner. The anteriormost rays are the first to 

 ossify at 5 mm, and ossification continues pos- 

 teriad. The last two fin rays are gradually sepa- 

 rated beginning at metamorphosis in a manner 

 described by Berry ( 1969). The full complement of 

 7 spines and 25 to 30 soft rays is present at 10 mm. 

 The dorsal spines are of almost uniform height in 

 the larvae. In early juveniles (17 mm), their 

 height is about half that of the soft rays. The first 

 and second dorsal fins are continuous throughout 

 the larval and transition stages. The full comple- 

 ment of 2 spines and 19 to 20 soft rays in the anal 

 fin is completed at 10 mm. 



Caudal fin formation has begun in the smallest 

 larva (3.8 mm). This is indicated by the presence of 

 a thickening near the tip of the notochord. When 





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