RICHARDSON and LAROCHE DEVELOPMENT AND OCl'URRENCE OF ROCKFISHES 



and V to VIII above the first and second saddles. 

 By 39 mm the outer half of the fin is completely 

 pigmented, while two unpigmented areas remain 

 on the proximal half of the fin between the two 

 pigment bars. Melanophores are added on the sec- 

 ond dorsal fin above the fourth saddle until the 

 proximal one-fourth of the fin between rays 2 and 

 13 or 14 is pigmented. The base of the caudal fin 

 never becomes outlined with melanophores, but 

 some melanophores develop on the dorsal second- 

 ary caudal rays. 



Recently preserved pelagic juveniles of S. pin- 

 niger, 32 to 35 mm, are covered with orange 

 chromatophores which are lost during prolonged 

 preservation. They are present on the dorsal part 

 of the head, on the snout, around the orbit, and on 

 the opercle. On the body they are concentrated 

 along the myosepta and lateral midline, with 

 greater numbers on the dorsal half of the body but 

 also e.xtending to the ventral margin. Orange 

 chromatophores are also concentrated on the spi- 

 nous dorsal fin, along the basal one-fourth of the 

 caudal fin, and the anal fin membrane around the 

 anal spines. 



A general increase in melanistie pigmentation 

 occurs in benthic juveniles >59 mm. On the head, 

 the two pigment bars beneath the orbit remain 

 distinct and extend over the operculum. Pigment 

 increases between the saddles obscuring the pat- 

 tern seen on pelagic juveniles. Melanophores are 

 added to both the inner and outer surfaces of the 

 pectoral fin base and on the basal one-third of the 

 pectoral fin blade. The pelvic fin remains unpig- 

 mented. The addition of melanophores to the spi- 

 nous dorsal fin obscures the pattern seen on 



pelagic juveniles although the black blotch re- 

 mains intense and distinct. The entire caudal fin is 

 lightly pigmented with more intense pigment oc- 

 curring over the bases of the primary rays and all 

 upper secondary rays. 



Occurrence (Figures 10, 11). — Adults of S. ptn- 

 ntger occur between Cape Colnett, Baja Califor- 

 nia, and southeast Alaska (lat. 56" N, long. 134° 

 W) (Hart 1973). Off Oregon they are most common 

 on the continental shelf between 100 and 200 m 

 (Snytko and Fadeev 1974). A major population 

 concentration has been found between lat. 44°30' 

 and 45" N off Oregon (Snytko and Fadeev 1974). 



:Li.-^_ 



iui 



£ 



<^ 10 



MAR 



-H 1 H/—< 1 



APR 



-I 1 w^^ 1 



MAY 



JUN 



'< II f 



AUG 



40 60 60 100 



Standord Length (mm) 



120 180 190 



Figure ll. — Seasonal occurrence of larvae and juveniles of 

 Sebastes pinniger off Oregon. Data from 1964 to 1975 combined. 

 Dashed line separates pelagic and benthic stages. 



- Larvae 



Pelagic Juveniles 



TIj" 



T r 



f Benthic Juve 



uveniles 



Figure lO. — Number of specimens and location of capture of larvae and juveniles of Sefeasfespjnm^er off Oregon 1 1964-75 1 described in 



this paper- 



29 



