FISHERY BULLETIN: VOL. 79, NO. 2 



20 



AUG 



20 



in 



c „ 

 <u 

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^ lOr 

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Lx 



SEP 



OCT 



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NOV 



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DEC 



20 40 60 



Stondord Length (mm ) 



80 



Figure lO. — Seasonal occurrence of larvae and juveniles of 

 Sehastes zacentrus off Oregon. Data from 1961 through 1978 

 combined. Solid bars indicate pelagic stages, open bars indicate 

 benthic stages. 



COMPARISONS 



Prior to this paper, developmental series of 12 of 

 the 69 northeast Pacific (including Gulf of Califor- 

 nia) species of Sebastes had been described: S. 

 cortezi, S. crameri, S. Gulf Type A, S. flavidus, S. 

 helvomaculatus , S. jordani, S. levis, S. mac- 

 donaldi, S. melanops , S. melanostomus, S. 

 paucispinis, and S. pinniger (Moser 1967, 1972; 

 Moser et al. 1977; Moser and Ahlstrom 1978; 

 Richardson and Laroche 1979; Laroche and 

 Richardson 1980). Comparisons among a number 

 of these species were discussed by Richardson and 

 Laroche (1979) and Laroche and Richardson 

 (1980). 



Young stages of S. entomelas are relatively slen- 

 der, vdth relatively light pigmentation, only mod- 

 erate head spines, and pectoral and pelvic fins of 

 moderate length. The ontogeny of S. entomelas is 

 very similar to that of S. flavidus and S. melanops 

 which also are moderately slender with only mod- 

 erate head spines. Pigmentation develops in simi- 

 lar fashion in all three species, i.e., along the dor- 

 sal and lateral midlines, although it is less intense 

 in S. entomelas. None of the three species develop 



pigment saddles. Larvae and juveniles of the three 

 are separable by meristic characters. 



Young S. zacentrus are comparatively deep 

 bodied, with relatively large head and head spines, 

 rather light pigmentation, moderately long pec- 

 toral fins, and relatively long pelvic fins especially 

 in the early stages. Other deep-bodied ( >30'7f SL) 

 forms includes, crameri, S. melanostomus, andS. 

 pinniger. Among these species, head spines are 

 pronounced in all but S. crameri. The early lack of 

 pigmentation and later development of five pig- 

 ment saddles in S. zacentrus is shared with S. 

 crameri, S. helvomaculatus, S. levis, S. melano- 

 stomus, S. paucispinis, and S. pinniger, although 

 the saddles of S. zacentrus are less distinct than in 

 the other species. The presence of pigment along 

 the dorsal body surface beneath the dorsal fins of 

 postflexion larvae and pelagic juveniles of S. 

 zacentrus is also seen in S. flavidus, S. jordani, 

 and S. melanops. These three species develop a 

 dense dorsolateral covering of melanophores that 

 is not restricted to saddles. Larvae and juveniles of 

 S. zacentrus are distinguishable from all of these 

 species on the basis of meristic characters. 



HEAD SPINE NOTES 



A group of four similar species, S. entomelas, 

 S. flavidus, S. melanops, and S. mystinus occur 

 off Oregon and are difficult to identify and sepa- 

 rate as larvae and juveniles. We have discovered 

 that literature describing head spine patterns 

 among this group of species is inaccurate and con- 

 tradictory. After completion of our work on S. 

 flavidus and S. melanops i Laroche and Richardson 

 1980) and during the course of our present work on 

 S. entomelas, we found undescribed variation in 

 head spine patterns among the species of this 

 group. To insure accurate identification of variant 

 specimens, we quantified and compiled data on 

 spine pattern variation among this group of 

 species. This new information is summarized here. 

 It will aid in identification and separation of the 

 species within the group, particularly of variant 

 specimens. 



The original description of Sebastes entomelas 

 (Jordan and Gilbert 1880) described the preocular, 

 supraocular, and postocular spines as minute, 

 sharp, and concealed by scales. Phillips (1957) re- 

 ported the above spines plus the tympanic spine 

 were present on specimens "under about eight 

 inches ..." (203 mm) long and become "nearly all 

 obsolete" in large specimens with occasionally the 



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