RICHARDSON and LAROCHE: DEVELOPMENT AND OCCURRENCE OF ROCKFISHES 



MAR 



40 60 eO 100 



Stondofd Length (mm) 



20 140 



Figure 6. — Seasonal occurrence of larvae and juveniles of 

 Sebastes cramen off Oregon. Data from 1961 to 1975 combined. 

 Dashed line separates pelagic and benthic stages. 



which a larva (15.7 mm) was taken was 28 km 

 (depth 95 m). The farthest offshore occurrence on 

 this transect was a 26 mm pelagicjuvenile 194 km 

 offshore. Benthic juveniles were generally taken 

 nearer to shore than larvae or pelagic juveniles at 

 depths of 55 to 200 m. Most pelagic specimens 

 came from Isaacs-Kidd midwater trawls towed 

 obliquely through the water column. Four speci- 

 mens, 17.7, 24.0, 38.2, and 56.9 mm, were collected 

 in a neuston net in June, 56 to 65 km off Newport. 

 Spawning times reported for S. crameri are 

 November through March off California (Phillips 

 1964) and primarily February off Oregon, 

 Washington, and British Columbia (Westrheim 

 1975; Westrheim et al. see footnote 7). However, 

 mature females with ovaries containing embryos 

 have been collected in February, March, ,'\pril. 

 and June (Westrheim et al.,^ see footnote 7; Mar- 

 ling et al.'"). Pelagic specimens in our collections 

 were taken primarily in April, May, and June 

 although two postflexion larvae were taken in 

 August. Larvae under 10 mm were only taken in 

 April and May. No specimens were taken Sep- 

 tember through February. Because of a lack of 

 information on larval growth, parturition time 



'Westrheim. S. J.. W R. Harling, D, Davenport, and M. S, 

 Smith. 1968. Preliminary report on maturity, spawning sea- 

 son, and larval identification of rockfishes iSeicstorfcsl collected 

 off British Columbia in 1968- Fish, Res. Board Can.. Manuscr 

 Rep. 1005, 28 p, 



'"Harlmg.W. R.. M.S. Smith, and N, A, Webb. 1971. Pre- 

 liminary report on maturity, spawning season, and larval iden- 

 tification of rockfishes iScorpaenidae) collected during 

 1970. Fish. Res. Board Can. Manuscr. Rep. 1137, 26 p. 



cannot be inferred. The wide range of lengths of 

 pelagic specimens, 8 to .30 mm in April, 9 to 36 mm 

 in May, 18 to 57 mm in July, indicates spawning 

 may be variable and protracted. Benthic juveniles 

 were taken March through July. 



In trawl surveys off Oregon, adults ranked sec- 

 ond in biomass only to S. diploproa of all 

 rockfishes collected over the continental slope and 

 fifth or sixth on the continental shelf (Demory et 

 al. 1976). Snytko and Fadeev ( 1974) reported it to 

 be one of the most abundant trawl-caught rockfish 

 species over the slope together with S. alutus, S. 

 saxicola, and S. diploproa. This species was one of 

 the three major contributors to the 1963-71 Ore- 

 gon landings of the Pacific ocean perch fishery 

 exceeding ,S. alutiis in 1971 (Niska 1976). Al- 

 though little can be said about the actual abun- 

 dance of larvae and juveniles off Oregon because of 

 the various kinds of samples examined and irregu- 

 lar nature of the sampling effort, they were one of 

 the more common kinds relative to the other 

 species of Sebastes in the samples. 



SEBASTES PINNIGER (GILL) 



(Figures 7, 8, 9) 



Literature. — Pigmentation of preextrusion larvae 

 of S. pinniger was listed in tabular form by Wes- 

 trheim (1975). Newborn to 2-wk-old larvae were 

 described by Waldron (1968) and the older larva 

 was redrawn by Moseretal. (1977). Mean length 

 of larvae at hatching is 3.6 mm SL. Newborn lar- 

 vae have an irregular double row of pigment (usu- 

 ally <16 melanophores) along the ventral midline 

 between the 18th and 22d myomere and some 

 pigment above the yolk sac near the anus. After 2 

 wk additional melanophores are present at the tip 

 of the lower jaw, on the ventral part of the yolk sac, 

 on the pectoral fins, along the dorsal midline in an 

 irregular double row between the 19th and 21st 

 myomeres, and in the hypural region. The ventral 

 midline melanophores may extend as far forward 

 as the 14th myomere. 



Identification (Table 7, Appendix Tables 2-6).— A 

 total of 269 specimens of S. pinniger, 7.9 to 181 

 mm long, were identified. Juveniles were iden- 

 tified using the following combination of charac- 

 ters compiled from specimens in our collections: 



Gill rakers = 40-45, left arch; 38-46, right arch 



Lateral line pores = 40-45 



Pectoral fin rays = 16-18, usually 17 



19 



