FISHERY BULLETIN: VOL. 72, NO. 4 



Figure 7. — Pelagic juvenile of Sebastolobus macrochir from off Kamchatka (27.2 mm). 



than in S. altivelis. In S. alascanus larvae and 

 pelagic juveniles 10 to 30 mm long the fin depth 

 averages 14% of the body length (range of 12 to 

 16%). In 22- to 60-mm benthic juveniles this is 

 reduced to an average of 10% (range of 9 to 11%). 



Ossification of the pectoral fin rays begins in 

 6.0-mm larvae of Sebastolobus (Table 5). The full 

 complements of pectoral rays, 23 to 24 for S. al- 

 tivelis and 21 to 22 for S. alascanus, are present 

 in 7-mm larvae (Tables 5, 6). 



The pelvic fin buds appear in larvae of about 

 6.0 mm and elongate to about 12% of the body 

 length by the completion of notochord flexion. Fin 

 length increases to about 17 to 18% of the body 

 length in post-flexion larvae up to 10 mm in 

 length. In S. altivelis this increases further to 

 about 24% in pelagic juveniles 20 mm long, and 

 averages 24% (range of 21 to 27%) for the re- 

 mainder of the pelagic phase. There is a slight 

 decrease to 22% (range of 21 to 24%) in benthic 

 juveniles up to 60 mm long. The pelvic fin is 

 slightly shorter in S. alascanus averaging 19% 

 (range of 18 to 20% ) in 10- to 20-mm specimens, 

 and 21% (range of 18 to 33%) in larger pelagic 

 juveniles and in benthic juveniles up to 60 mm 

 long. The full complements of one spinous ray 

 and five soft rays are beginning to ossify in 7-mm 

 larvae ofS. altivelis and S. alascanus. 



The hypural thickening of the caudal fin first 

 appears in larvae about 3.5 mm long. The hypu- 

 rals begin to ossify in 7-mm larvae of both species 



and the full complements of two superior and two 

 inferior elements are ossified in 12-mm larvae of 

 both species. The full complements of eight 

 superior and seven inferior principal caudal rays 

 are beginning to ossify in 7-mm larvae o{ Sebas- 

 tolobus. The procurrent caudal rays also begin to 

 ossify in 7-mm larvae. The full complements of 6 



.•'' 



STONDiRD LENGTH Imiu) 



Figure 8. — Relationship of body depth to body length in de- 

 velopmental stages of Sebastolobus. Small dots = larvae less 

 than 10 mm not identifiable to species. Large open circles = 

 larvae and pelagicjuveniles ofS. altivelis. Large dots = benthic 

 specimens of S. altivelis. Open triangles = larvae and pelagic 

 juveniles of S. alascanus. Solid triangles = benthic specimens of 

 S. alascanus. Solid squares = pelagic specimens of S. mac- 

 rochir. Lines fitted by method of least squares. No regression 

 line drawn for S. macrochir. 



878 



