FISHERY BULLETIN: VOL. 87, NO. 3, 1989 

 Table 2.— Average body proportions (% ± standard deviation) for larvae of 



Pigmentation 



Pigmentation of yolk sac and early preflexion 

 larvae was described by Orton (1953) from speci- 

 mens cultured in the laboratory. Newly hatched 

 larvae have a few melanophores on the hindgut 

 and in a short midventral row at the base of the 

 tail. At about midway through yolk absorption, 

 small melanophores appear on the ventral sur- 

 face of the yolk sac (Fig. 2A); the row above the 

 hindgut becomes heavier, extending forward to 

 about the midpoint of the yolk sac; and the mid- 

 ventral tail series has increased to 7-11 mela- 

 nophores, extending posteriad along most of the 

 tail. A series of small melanophores appears on 

 the dorsal midline along the posterior half of the 

 tail, and several small melanophores are present 

 above and below the tip of the notochord. Near 

 the end of yolk absorption the eyes become pig- 

 mented; the dorsal gut pigment becomes heavier 

 and extends over the entire gut; and the ventral 

 tail melanophores enlarge, partly by aggi'ega- 

 tion, as do the melanophores on the dorsal 

 margin of the tail. 



In early preflexion larvae the ventral midline 

 series of 5-8 large melanophores is continuous 

 with the dorsal gut melanophores. A space sep- 

 arates the ventral tail series from one or more 

 smaller melanophores near the tip of the noto- 

 chord. The dorsal midline series consists of ca. 

 1^ large melanophores posteriorly on the tail, 

 with one to several small melanophores near the 

 tip of the notochord. A large melanophore de- 

 velops above the midbrain and one forms on the 



nape. Internal pigment develops below each otic 

 capsule, appearing as a continuation of the dorsal 

 gut pigment. The series of small ventral gut 

 melanophores coalesces into 3 pigment loci, each 

 usually containing a single melanophore: 1) an 

 embedded melanophore anterior to the hver, 2) a 

 surface midventral spot just posterior to the 

 hver, 3) a surface midventral spot just anterior 

 to the hindgut (Fig. IC). 



During preflexion the dorsal gut pigment ex- 

 pands to the lateral surface of the gut. The 

 dorsal midline series increases anteriorly be- 

 ginning in early preflexion, and soon extends 

 from the head nearly to the tip of the tail. The 

 smaller melanophores near the tip of the tail 

 disappear or are reduced to one. Dorsal mela- 

 nophores number 11-15. The smaller ventral 

 spots at the notochord tip disappear, except for 

 one, which persists in the fmfold about halfway 

 between the end of the ventral pigment series 

 and the tip of the tail. 



During late preflexion and flexion stages, pig- 

 ment increases on the midbrain and appears on 

 both the forebrain and hindbrain. Paired mela- 

 nophores develop on the roof of the mouth below 

 the nasal capsules and olfactory lobes, and one or 

 more form at the tip of the lower jaw. As the 

 pigment associated with the otic capsule in- 

 creases, an embedded stripe passing through the 

 eye region is formed (Fig. 2E). One or two sur- 

 face melanophores appear posterior to the eye in 

 the opercular region. Melanophores appear on 

 the tip of the lower jaw, at the angle of the jaw, 

 and later along the rami of the jaw. A large 



750 



