FISHERY BULLETIN VOL, 77. NO, 1 



Very weak serrations appear on the second and 

 fourth posterior preopercular spines of most larger 

 larvae and smaller pelagic juveniles. All five pos- 

 terior preopercular spines are present on speci- 

 mens >8.0 mm. The first and third anterior 

 preopercular spines seen on the smallest larva are 

 no longer visible on specimens >23 mm. The sec- 

 ond anterior preopercular spine never develops. 



The superior and inferior opercular spines are 

 present on all specimens >8 mm. The interopercu- 

 lar spine is present at 8.8 mm and persists into 

 benthic juveniles. The subopercular spine is pres- 

 ent just above the interopercular spine on the 

 largest benthic juvenile, 183 mm. 



The supraocular ridge and the anterior margin 

 of the postocular spine are serrated on specimens 

 up to 23.8 mm. The preocular and supraocular 

 spines are first seen as bumps in a 13.4 mm speci- 

 men. Serrations are present on the supraocular 

 spine but disappear along with those on the su- 

 praocular ridge on larger pelagic juveniles. 



The first superior infraorbital spine is visible up 

 to 23 mm. The second superior infraorbital spine 

 appears on specimens 12 to 23 mm. The fourth 

 superior infraorbital spine is present on larvae >8 

 mm and the third superior infraorbital spine is 

 present on larvae >13.4 mm. The third and fourth 

 spines both disappear by 23 mm. The first and 

 second spines of the inferior infraorbital series are 

 present on all specimens >8 mm but appear only 

 as blunt projections on benthic juveniles. The 

 third inferior infraorbital spine never develops. 

 The nasal spine appears as a bump by 9 mm and 

 becomes strong and sharp during the larval 

 period. 



The tympanic spine develops by 41.6 mm and 

 appears as a strong sharp spine on benthic 

 juveniles. The pterotic spine is present on all 

 specimens >41.6 mm. The inferior posttemporal 

 spine is present on all specimens examined but is 

 minute on the two benthic juveniles, 136 and 183 

 mm, and probably disappears in larger specimens. 

 The supracleithral spine is present on all speci- 

 mens >8.0 mm. The superior posttemporal ap- 

 pears at 13.4 mm and is present on all larger 

 specimens. Posterior to the opercle the cleithral 

 spine appears on all specimens >19 mm. 



Scale Formation. — Lateral line pores first appear 

 anteriorly and are visible on specimens >17 mm. 

 Scale formation begins on pelagic juveniles >23 

 mm. 



Pigmentation. — The smallest larva of S. hel- 

 vomaculatus, 7.7 mm (similar to the 8.0 mm 

 specimen illustrated), has pigment on the head 

 over the brain. Melanophores line the inner tip of 

 the lower jaw. In the abdominal region, an inter- 

 nal melanistic shield is present over the dorsolat- 

 eral surface of the gut. No other pigment is visible 

 on the body. The pectoral and pelvic fins are 

 fringed with expanded and fused melanophores 

 and have a light scattering of more contracted, 

 elongate melanophores on the fin blades. Both 

 inner and outer pectoral fin base surfaces are un- 

 pigmented. 



During larval development, pigment over the 

 brain becomes obscured. At 13.4 mm pigment in- 

 side the lower jaw disappears. Specimens >17 mm 

 develop two to six internal melanophores dorsally 

 on the opercle. 



During the transformation period, 12.0 to 18.6 

 mm, two or three melanophores may appear just 

 posterior to the orbit on specimens >18 mm. In- 

 ternal gut pigment increases ventrolaterally 

 reaching the ventral surface of the gut by 17.9 

 mm. The anterior margin of the cleithrum is usu- 

 ally unpigmented. A patch of 9 to 10 large stellate 

 melanophores appears laterally on the caudal 

 peduncle at 12.0 mm at the beginning of the trans- 

 formation period. Melanophores are added to this 

 patch until it extends to the dorsal body surface at 

 = 18 mm. Melanophores in this patch often appear 

 expanded and fused. The pectoral and pelvic fins 

 remain fringed with pigment although this may 

 not be obvious if the fins are frayed. The number of 

 melanophores on the fin blades generally de- 

 creases. 



During the pelagic juvenile period, 19.8 to 41.6 

 mm. pigment appears over the head surface, 

 snout, and upper lip of specimens "^22 mm. 

 Melanophores are added along the posteroventral 

 margin of the orbit and a patch of melanophores 

 appears just dorsal to the first superior infraor- 

 bital spine. The internal pigment patch on the 

 operculum remains distinguishable. Internal gut 

 pigment becomes increasingly obscured by muscu- 

 lature. A single saddle of melanophores develops 

 on the dorsal surface of the body over the nape and 

 beneath the spinous dorsal fin anterior to dorsal 

 spine XI. The first melanophores generally appear 

 there at the onset of the pelagic juvenile stage, 

 although a few may develop earlier. This saddle 

 extends ventrolaterally from the nape to the vicin- 

 ity of the supracleithral spine and from the spi- 

 nous dorsal fin halfway to the lateral line by 22 



36 



