RICHARDSON and LAROCHE DEVELOPMENT AND OCCURRENCE OF ROCKFISHES 



anus distance is markedly shorter in larvae and 

 juveniles oCS.jordaiii (36-53'^< SL) compared with 

 the other species. 



The pectoral fins in S.jordani remain compara- 

 tively short (7-22% SL) during pelagic develop- 

 ment while those of S. levis attain an exceptional 

 size (to 45'7( SL). Late larval stages of S. pauci- 

 spinis also have outstandingly long pectoral fins 

 (36'"f SL). Fin lengths among the other species are 

 intermediate by comparison and vary to a lesser 

 degree during development. The pelvic fins of S. 

 pauc7spi>!ii' also become extraordinarily long (35'> 

 SL) during the late larval period whereas those of 

 S.jordani remain relatively short. 



Parietal spine length varies among species with 

 the largest spines appearing in early larvae of S. 

 helvornacu/atus {279i HL) and S. sp. Gulf Type A 

 (25-349f HL). This spine is noticeablely short on S. 

 cramen (3-7% HL) during the entire pelagic 

 phase. The third preopercular spine is outstand- 

 ingly long on early larvae of S. macdonaldi (35% 

 HL) and S. pinniger (34% HL) but is compara- 

 tively short on S. cramen (17% HL) as is the 

 parietal. 



Pigmentation on the paired fins varies from the 

 unpigmented condition in S.jordani to the heavily 

 pigmented fins of S. macdonaldi and S. crameri. 

 The pectoral fins of S. cortezi are pigmented at the 

 fin base but not the outer margin, while pigment is 

 primarily concentrated on the outer margin of the 

 fins in S. paucispinis, S. levis, and S. helvomacu- 

 latu.s at least during the early pelagic period. Pec- 

 toral fins of S. pinniger, S. melanostomus, and S. 

 sp. Gulf Type A are lightly pigmented. 



General body pigmentation differs among the 

 species considered. Larvae of S. pinniger have a 

 '•haracteristic lack of body pigment. A patch of 

 uape pigment develops early in S. crameri and S. 

 macdonaldi. appearing more pronounced in the 

 former species. Postflexion larvae of both S. cram- 

 eri and S. macdonaldi develop pigment on the 

 entire spinous dorsal fin. A characteristic black 

 blotch develops on the posterior portion of the first 

 dorsal fin in pelagic juveniles of S. pinniger. Lar- 

 vae of S. melanostomu.'i, S. paucispini.'i, and S. 

 macdonaldi have a characteristically low number 

 of ventral midline melanophores, 4 to 11 (mean 8), 

 6 to 14 (mean 9), and 6 to 14 (mean 8), respectively. 

 A patch ofpigment forms on the caudal peduncle of 

 S. helvomaculatus , S . paucispinis, S.jordani, and 

 S. cortezi. The form of the patch varies with the 

 species and is most pronounced in S. hel- 

 vomaculatus. One characteristic melanophore ap- 



pears at the base of the caudal fin in S. cortezi, 

 while melanophores form a line ofpigment at the 

 base of the caudal fin in S.jordani, but not in any 

 of the other species. 



Pelagic juveniles of S. helvomaculatus develop 

 only one melanistic pigment saddle beneath the 

 spinous dorsal fin. Five distinct saddles form on S. 

 macdonaldi, S. crameri, S. levis, S. paucispinis, 

 and S. pinniger in comparable locations on the 

 body although a more blotchy pattern develops on 

 S. pinniger. On S. melanostomus, three pro- 

 nounced melanistic bars develop on the body. Ap- 

 parently no obvious saddles or bars develop on 

 pelagic juveniles of S. jordani or S. cortezi. 



These comparisons together with distinguish- 

 ing features of each species given by us, Moser 

 (1972), Moser et al. (1977), and Moser and 

 Ahlstrom (1978), and range of occurrence should 

 aid in identification of all but the smallest larvae. 

 As additional species are described, such compari- 

 sons may also provide insight into relationships 

 within the genus Sebastes. 



ACKNOWLEDGMENTS 



We thank H. Geoffrey Moser for helpful advice 

 and for the use of unpublished data on color pat- 

 tern in a livejuvenile of S. crameri. Stuart G. Poss 

 offered useful advice on head spine terminology. 

 During the course of this study the following 

 people provided helpful information on Sebastes 

 spp.: Carl Bond, Jerry Butler, William N. Esch- 

 meyer, Colin Harris, Michael Hosie, Andy Lamb, 

 Bruce M. Leaman, Alex E. Peden. Jay C. Quast, 

 David Stein, Arthur D. Welander, Sigurd J. Wes- 

 trheim, Norman J. Wilimovsky. Range Bayer, 

 Robert A. Behrstock, Carl Bond, Jerry Butler, 

 Colin Harris, Michael Hosie, Robert Lea, Law- 

 rence Moulton. and Alex Peden provided addi- 

 tional specimens of Sebastes to examine. Special 

 thanks are extended to William G. Pearcy for al- 

 lowing us to use his extensive midwater trawl 

 collections from waters off Oregon. Lo-Chai Chen, 

 H. Geoffrey Moser, Stuart G. Poss, and Sigurd J. 

 Westrheim reviewed an earlier draft of the man- 

 uscript. This research was supported by a 1-yr ( 16 

 June 1976-15 June 1977) contract No. 03-6-208- 

 35343. 



LITERATURE CITED 



AHLSTROM. E. H. 



1961. Distribution and relative abundance of rockfish 



39 



