MILLER and SUMIDA: DEVELOPMENT OF CARANX MATE 



Figure 3A. — Eighteen-day old larva, Caranx mate, 7.67 mm SL. 



Figure 3B. — Thirty-three-day old larva, Caranx mate, 12.60 mm SL. 



The operculum was never heavily pigmented, 

 although melanophores formed along the region 

 between the preopercular spines of larvae from 

 day 8 to 16 (3.5-6.2 mm SL), as the spines were 

 being resorbed. In addition there were several 

 melanophores scattered over the upper region of 

 the operculum posterior to the eye. 



Body Pigmentation 



ABDOMINAL REGION.— The abdominal 

 region of the omaka larvae following yolk absorp- 

 tion as used here refers to the peritoneal cavity 

 with its overlying tissue. At six days (3.0 mm 

 SL) the one or two faintly pigmented melano- 

 phores could be seen immediately ventral to the 

 base of the pectoral fin. These melanophores 

 persisted until the larvae were 14 days old 

 (5.2 mm SL) (Figure 2C, D). A few melanophores 

 were scattered over the abdominal wall in the 

 early larvae with increasing numbers being 

 formed in older larvae. 



The spherical gas bladder was apparent by the 

 sixth day (3.0 mm SL) with its dorsal cap of 

 embedded pigmentation. The gas bladder was 



gradually depressed into an elliptical shape by 

 day 10 (4.0 mm SL) and its pigment largely 

 obscured with the increasing growth of muscula- 

 ture dorsally. 



A line of melanophores developed by day 6 

 (3.0 mm SL) (Figure 2C) extending along the 

 dorsal wall of the abdominal cavity from the 

 gas bladder to the terminus of the gut where it 

 converged with the ventral line of melanophores 

 along the edge of the hypomeres (see section on 

 ventrum pigmentation). This pigmentation in- 

 creased in density through day 8 (not illustrated) 

 until it was obscured by the growth of overlying 

 tissue by day 12 (Figure 2D). This pigmentation 

 had a diffused appearance owing to its internal, 

 dorsal position, but consisted of discrete melano- 

 phores. 



Also evident in six-day-old larvae was peri- 

 toneal pigmentation along the ventral edge of the 

 abdominal cavity, including a small precleithral 

 cluster of melanophores, a larger cluster just 

 ventral to the liver (where the pelvic bud sub- 

 sequently appeared), and a row of melanophores 

 extending from the ventral surface of the stomach 

 to the anus. These pigments gradually diminished 



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