APRIETO: EARLY DEVELOPMENT OE EIVE CARANGID EISHES 



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two spines fuse at the posterior wall of the abdomi- 

 nal cavity which becomes elongated vertically. 

 Consequently, the long and slender gut forms ver- 

 tical loops following the shape of the abdominal 

 cavity. The gut opening is pushed anteriorly and 

 lies adjacent to the base of the pelvic fins. Snout- 

 to-anus distance decreases relative to standard 

 length. It is 56% at 2.5 mm and declines to 40% at 

 the end of the larval period. During the early 

 juvenile stages, snout-to-anus distance had an av- 

 erage of 38%. 



The length and width of the head increases rela- 

 tive to standard length. Head length is 31.0% in 

 the smallest larva (2.5 mm) and does not increase 

 substantially until the juvenile period when it 

 attains a maximum of 41.9% at 23.9 mm. To ob- 

 tain the true depth of the head and not the body 

 depth at the head region, the measurement is 

 taken from the posterior margin of the preopercle 

 from the dorsal margin of the head to the articula- 

 tion of the mandible and maxillary. Head depth is 

 100% of the head length at 2.5 to 3.2 mm. There- 

 after, head depth exceeds head length. During the 

 larval period, the head is deepest at 4.6 mm when 

 it is 140% of the head length. This is, however, 

 exceeded by the progressive deepening of the head 

 during the transition and juvenile stages with a 

 maximum of 182% and an average of 158%. The 

 dorsal profile of the snout is slightly concave in the 

 early larval period (2.5-3.8 mm) but becomes 

 straight in older and transforming larvae. The 

 nasal, frontal, and supraoccipital bones become 

 markedly elongated and slope steeply, giving the 

 head an almost vertical anterior profile. 



The eyes are round and large. Relative orbit 

 diameter increases during the larval and juvenile 

 development; it is 32% at 2.5 mm and attains a 

 maximum of 37% at notochord flexion with an 

 average of 31% during the larval and transition 

 periods. In the juveniles, orbit diameter decreases 

 to a range of 20 to 27%. 



The orbital and supraoccipital crests are well 

 marked in early larval stages up to 5 mm. The 

 crests are gradually resorbed and are vaguely vis- 

 ible at metamorphosis. Preopercular marginal 

 spines consist of 4 to 7 long and strong spines while 

 the lateral surface spines are smaller and limited 

 to the lower surface. All preopercular spines are 

 resorbed at transformation. Scales are absent. 



Pigmentation 



The common larval pattern of pigmentation in 



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