mental series differ in many characters. Most ap- 

 parent is the early lack of pigment and the later 

 development of distinct pigment saddles under 

 the dorsal fins of postflexion and pelagic juvenile 

 S. crameri, S. helvomaculatus , S. levis, S. 

 melanostomus , S. paucispinis, and S. pinniger. 

 The only species described to date which has pig- 

 ment along the dorsal surface under the dorsal 

 fins in postflexion larvae and pelagic juveniles, 

 similar to that of S. flavidus and S. melanops, is 

 S.jordani. However, S.jordani has a very short 

 snout to anus distance/SL ratio, 36 to 53% SL, 

 compared with 57 to 60.3% SL and 58.0 to 61.3% 

 SL for postflexion larvae and pelagic juveniles of 

 S. flavidus and S. melanops, respectively. 

 Sebastes cortezi, S. Gulf Type A, and S. mac- 

 donaldi are all deeper bodied than S. flavidus and 

 S. melanops, and both S. Gulf Type A and S. mac- 

 donaldi have much longer parietal spines. 



Other Oregon species which are easily confused 

 with S. flavidus and S. melanops during larval 

 and juvenile development are the widow rockfish, 

 S. entomelas, and the blue rockfish, S. mystinus. 

 However, pelagic and benthic juveniles of these 

 species are separable based on the presence of 

 preocular and supraocular spines, usually >15 

 dorsal soft rays, and usually >8 anal soft rays 

 (see Appendix Table 1). 



Sebastes mystinus is separable from the other 

 three species at all sizes after fin formation has 

 occurred, =9.0 mm, since it is the only species 

 which usually has 16 dorsal soft rays and 9 anal 

 soft rays. Sebastes entomelas and S. mystinus 

 both usually have 18 pectoral rays which distin- 

 guish them from S. melanops, which usually has 

 19 rays. Sebastes flavidus and S. entomelas are 

 the only pair of species which are not readily 

 separated by fin counts. However, both S. en- 

 tomelas and S. mystinus develop supraocular 

 spines, which appear on specimens larger than 

 = 17 mm, while S. flavidus and S. melanops rarely 

 develop supraocular spines. In addition to these 

 characters, larvae and pelagic juveniles of S. en- 

 tomelas and S. mystinus either lack or have a 

 reduced number of melanophores at the articula- 

 tions of the anal fin rays and on the ventral surface 

 of the caudal peduncle. We have a description of 

 the development of S. entomelas in preparation. 



Sebastes ciliatus (from British Columbia and 

 Alaska) and S. serranoides (from California) are 

 other similar species which should be CEirefully 

 considered when identifying specimens from 



areas where they also occur. We have not had the 

 opportunity to observe specimens of S. ciliatus 

 and cannot assess its potential for causing confu- 

 sion. We have examined 20 benthic juvenile S. 

 serranoides. Although the head spine pattern in 

 S. serranoides is the same as in S. flavidus and S. 

 melanops, S. serranoides usually has <18 pec- 

 toral rays and >8 anal soft rays which will usu- 

 ally separate them from S. flavidus and S. 

 melanops (see Appendix Table 1). All of the 

 species discussed, excluding S. ciliatus for which 

 we have no information, have to some extent a 

 concentration of melanistic pigmentation on the 

 posterior portion of the spinous dorsal fin occur- 

 ring on juveniles. Sebastes flavidus and S. 

 melanops have the most intensely pigmented 

 "black blotch." Sebastes mystinus has a more 

 darkly pigmented spinous dorsal fin which pre- 

 sents little contrast from the pigment in the area 

 of the black blotch. Sebastes entomelas and S. ser- 

 ranoides usually have a less distinct "blotch" 

 with most of the pigment concentrated in a fringe 

 along the posterior distal edge of the spinous dor- 

 sal fin membrane. 



The most important characters useful in 

 separating larval and juvenile S. flavidus and S. 

 melanops from each other are pectoral ray 

 number (usually 18 versus 19), lateral line pore 

 number (usually >50 versus <50), and caudal 

 peduncle depth/length ratio (mean values 0.73, 

 0.64, 0.64, 0.80 versus 0.88, 0.78, 0.74, 0.92 in 

 postflexion larvae, transforming, pelagic 

 juvenile, and benthic juvenile specimens, respec- 

 tively). Sebastes flavidus taken at the same loca- 

 tion as S. melanops appear to have less dense 

 melanistic pigment. Benthic juveniles of S. flav- 

 idus seem to inhabit deeper waters, >20 m, while 

 S. melanops inhabits estuaries, tidepools, and 

 offshore waters <20 m. Landing data tabulated 

 by Niska ( 1976) indicates a corresponding differ- 

 ence in "preferred" depth for adults with S. flav- 

 idus taken chiefly between 54 and 218 m and S. 

 melanops taken mainly in water <54 m. 



ACKNOWLEDGMENTS 



Special thanks are extended to William G. 

 Pearcy for allowing us to use his extensive mid- 

 water trawl collections from waters off Oregon. 

 Additional specimens were provided by Carol 

 Anderson, Range Bayer, Carl Bond, William Esch- 

 meyer, Wendy Gabriel, Gary Hepman, Gary 

 Hewitt, Michael Hosie, Earl Krygier, Robert Lea, 



922 



