FISHERY BULLETIN: VOL. 80, NO. 3 



Figure 3. — Genyonemus I i neat us yolk-sac 

 larvae; a) 6 h after hatching, 1.54 mm; b) 

 48 h after hatching, 2.48 mm; c) 68 h after 

 hatching, 2.36 mm. All illustrations are of 

 freshly preserved reared larvae. 



Head pigment changes little during the first 

 60 h (ca. 13°C). After this it condenses to a few 

 melanophores over the forebrain and midbrain. 

 These melanophores may be lost by the end of the 

 yolk-sac stage except for one or two melano- 

 phores on the otic capsule. A small melanophore 

 first appears at the angular bone just at the end 

 of the yolk-sac stage. Eye pigmentation begins at 

 about 60 h (Fig. 3c) and is complete by 120 h after 

 hatching (ca. 13°C). 



During the first 24 h after hatching the dorsal 

 trunk melanophores begin to migrate ventrally, 

 condensing into bands at the nape, the anus, and 

 midtail at myomeres 16-18 (Fig. 3b). This pat- 

 tern persists but becomes indistinct as melano- 

 phores continue to migrate ventrally. 



By the end of the yolk-sac stage dorsal trunk 



pigment consists only of the large nape-finfold 

 melanophore, one or two smaller melanophores 

 near the level of the anus, one in the region of 

 myomeres 16-18, and one or two near the tip of 

 the notochord. Lateral melanophores may per- 

 sist in these same areas, although more often 

 they do not. Midventral trunk pigment increases 

 to a series of 8-10 melanophores, with those at 

 myomeres 9-10 and 16-18 usually larger. 



Oil droplet and yolk-sac pigment changes only 

 by condensing as the yolk is consumed. The ven- 

 tral hindgut melanophores persist through the 

 yolk-sac stage with the lower migrating to a posi- 

 tion adjacent to the anus. A single small melano- 

 phore usually moves to the dorsal midline of the 

 hindgut where the hindgut turns downward at 

 the fifth or sixth myomere. After about 60 h one 



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