FISHERY BULLETIN: VOL. 81, NO. 4 



sequently added from posterior to anterior along the 

 dorsal fin ray bases (Fig. 2c) so that by the end of the 

 larval period (ca. 16 mm) a continuous pigment line 

 lies along each side of the dorsal midline. 

 Melanophores develop on the membrane between 

 the dorsal fin rays at this time (Fig. 2d). 



Ventral tail pigment through most of the larval 

 period consists of 1 2 to 1 7 melanophores arrayed 

 along the length of the tail. Those at myomeres 17 to 

 21 (usually at 19 to 21) are distinctly larger, usually 

 dendritic (Fig. 3), and correspond to the posterior 

 ventral melanophore illustrated by Hildebrand and 

 Cable (1930) in a 3 mm specimen. Larvae smaller 

 than 5.7 mm typically have two or three enlarged ven- 

 tral melanophores, while larger specimens have none 

 to two. These lie at the posterior end of the anal fin in 

 larger specimens. Melanophores behind the 

 developing anal fin base (except the last 

 melanophore) extend internally during notochord 

 flexion. Those between the anus and myomere 19 or 

 20 extend internally early in larval development, but 

 tend to move downward onto the developing anal fin 

 ray bases during late flexion. They usually are 

 located entirely along the sides of the anal fin ray 

 bases in postflexion larvae (Figs. 2, 3). The last ven- 

 tral melanophore is associated with the developing 



caudal complex and becomes located along the lower 

 hypurals during notochord flexion. Melanophores 

 proliferate along the distal hypural edge in postflex- 

 ion larvae, forming a bar. Near the end of the larval 

 period melanophores extend from the bar along the 

 central caudal rays. At this time, melanophores also 

 develop on the membranes between the dorsal and 

 anal fin rays (Fig. 2d). 



Lateral pigment is first evident in postflexion larvae 

 (ca. 7.3 mm) as an internal melanophore above the 

 notochord at myomere 20 or 21. Melanophores are 

 added, first ventrally and then laterally, along the 

 vertebrae both caudad and cephalad. The cephalad 

 extension proceeds more rapidly. Hildebrand and 

 Cable (1930, fig. 33) apparently illustrated this inter- 

 nal pigmentation in an 1 1 mm specimen, but did not 

 mention it in the text. External pigment develops 

 posteriorly along the lateral midline soon after the 

 beginning of the cephalad extension of the vertebral 

 melanophores (Fig. 2a). This external pigment pro- 

 liferates both cephalad and caudad (more rapidly 

 cephalad), but always lags behind the vertebral pig- 

 ment (Fig. 2b). When the lateral pigment band 

 reaches the level of the anus, it begins to widen as well 

 (Fig. 2c), forming a broad lateral stripe from the oper- 

 cular margin onto the central caudal fin rays by the 



FIGURE 3. — Ventral view of Orthoprinti.s chrysoptera; a. 4.2 mm; b. 5.6 mm; c. 6.4 mm; d. 7.:i mm; e. 9.2 mm; 



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