FISHERY BULLETIN; VOL. 72, NO. 4 



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Figure 9. — Larvae of Harengula jaguana: A, 8.9 mm SL; B, 11.5 mm SL. 



rapidly on specimens longer than 18 mm, al- 

 though there was much individual variation. 

 Numerous stellate melanophores were present 

 over the brain, on the snout, jaws, and cheek 

 region of specimens between 18 and 24 mm. 



Gut and Trunk Region 



Paired series of melanophores, typical of 

 clupeid larvae, developed over the dorsolateral 

 surface of the foregut region and along the 

 ventral surface of the hindgut at about 4.5 mm. 

 Numbers of pairs in the series were variable, 

 ranging from 7 to 12 along the foregut and from 

 8 to 14 along the hindgut. Those on the foregut 

 usually were more evenly paired than those on 

 the hindgut. In specimens where the melano- 

 phores were contracted, pairs were easily dis- 

 tinguished, but when dispersed, the pairs often 

 tended to coalesce forming streaky lines of pig- 

 ment. The two series were retained until larvae 

 were 21 mm, but became indistinct on some 

 larvae between 18 and 21 mm. No distinct series 

 could be distinguished on specimens longer than 

 21 mm. 



Two series of melanophores were present in- 

 ternally. One series was found dorsal to the gut 

 and the second extended from the hindbrain pos- 

 teriorly along the vertebral column. Two melano- 

 phores appeared near the dorsal surface of the gut 

 near the anus at 4 to 5 mm, from which the 



series of melanophores dorsal to the hindgut 

 began to develop at 5 to 6 mm. The number 

 gradually increased from as few as 2 to 5 to 

 as many as 34 when larvae were 12 to 15 mm. 

 The first melanophores in this series developed 

 near the posterior of the hindgut; additional 

 melanophores developed anterior to those. The 

 series along the vertebral column first appeared 

 at 10 to 12 mm, and numbers gradually in- 

 creased to about 25. Melanophores in this series 

 first appeared just posterior to the hindbrain; 

 additional melanophores developed posterior to 

 them. The vertebral series was difficult to 

 distinguish in most specimens and was not in- 

 cluded in illustrations. Both series became in- 

 distinct on specimens longer than 18 mm because 

 larvae increased in body thickness. 



Two stellate melanophores developed at the 

 anal fin base between 11 and 13.5 mm. The 

 number increased as larvae grew. At 14 to 15 mm, 

 stellate melanophores appeared at the dorsal 

 fin base, the numbers increasing from one oi 

 two to eight or more at 18 mm. Between 18 and 

 21 mm, a few melanophores developed in the 

 dorsal fin of most individuals, and a paired 

 series of stellate melanophores developed pos- 

 terior to the dorsal fin along the dorsal midline. 

 One or two melanophores were present at the 

 bases of the pelvic fins in larvae longer than 

 15 mm. 



Stellate melanophores began to appear on the 



1118 



