328 



Abstract— The dusky rockfish (Se- 

 bastes ciliatus) of the North Pacific 

 Ocean has been considered a single 

 variable species with light and dark 

 forms distributed in deep and shal- 

 low water, respectively. These forms 

 have been subjected to two distinct 

 fisheries separately managed by fed- 

 eral and state agencies: the light deep 

 form is captured in the offshore trawl 

 fishery; the dark shallow form, in the 

 nearshore jig fishery. The forms have 

 been commonly recognized as the light 

 dusky and dark dusky rockfishes. From 

 morphological evidence correlated with 

 color differences in some 400 speci- 

 mens, we recognize two species cor- 

 responding with these color forms. 

 Sebastes ciliatus (Tilesius) is the dark 

 shallow-water species found in depths 

 of 5-160 m in the western Aleutian 

 Islands and eastern Bering Sea to 

 British Columbia. The name Sebastes 

 variabilis (Pallas) is resurrected from 

 the synonymy of S. ciliatus to apply to 

 the deeper water species known from 

 depths of 12-675 m and ranging from 

 Hokkaido, Japan, through the Aleu- 

 tian Islands and eastern Bering Sea, to 

 Oregon. Sebastes ciliatus is uniformly 

 dark blue to black, gradually lightening 

 on the ventrum, with a jet black peri- 

 toneum, a smaller symphyseal knob, 

 and fewer lateral-line pores compared 

 to S. variabilis. Sebastes variabilis is 

 more variable in body color, ranging 

 from light yellow to a more usual tan 

 or greenish brown to a nearly uniform 

 dark dorsum, but it invariably has a 

 distinct red to white ventrum. Syn- 

 onymies, diagnoses, descriptions, and 

 geographic distributions are provided 

 for each species. 



The dusky rockfishes (Teleostei: Scorpaeniformes) 

 of the North Pacific Ocean: resurrection of 

 Sebastes variabilis (Pallas, 1814) and a 

 redescription of Sebastes ciliatus (Tilesius, 1813) 



James W. Orr 



Resource Assessment and Conservation Engineering Division 



Alaska Fisheries Science Center 



National Marine Fisheries Service, NOAA 



7600 Sand Point Way NE 



Seattle, Washington 98115 



E-mail address: James Orr@noaa.gov 



James E. Blackburn 



Alaska Department of Fish and Game 



211 Mission Road 



Kodiak, Alaska 99615-9988 



Manuscript approved for publication 

 22 December 2003 by Scientific Editor. 



Manuscript received 20 January 2004 

 at NMFS Scientific Publications Office. 



Fish. Bull. 102:328-348(2004). 



Among the approximately 92 species 

 of Sebastes found in the North Pacific, 

 two commercially important species 

 long identified under the name Sebastes 

 ciliatus have been taxonomically prob- 

 lematic. The name S. ciliatus (Tilesius, 

 1813) has been commonly applied to 

 specimens considered to represent a 

 single variable species ranging from 

 northern Japan to British Columbia 

 (Barsukov, 1964; Westrheim, 1973; 

 Shinohara et al., 1994; Mecklenburg et 

 al., 2002), and the name S. variabilis 

 (Pallas, 1814) has been treated as a 

 junior synonym (Jordan and Gilbert, 

 1881; Eigenmann and Beeson, 1894; 

 Jordan and Evermann, 1898; Blanc 

 and Hureau, 1968). Two color forms 

 within S. ciliatus have been reported 

 and hypothesized to be distinct species 

 (Quast and Hall, 1972; Eschmeyer et 

 al., 1983; Kessler, 1985; Fig. 1). The 

 typically light-colored form, commonly 

 known as the light dusky rockfish, is 

 often found in large aggregations over 

 the outer continental shelf and upper 

 slope at depths down to 675 m, and 

 less frequently in nearshore habitats. 

 The dark-blue to black form, commonly 

 known as the dark dusky rockfish, is 

 found in more shallow habitats from 

 nearshore rocky reefs to depths no 

 greater than 160 m. 



These forms have been subjected to 

 two distinct fisheries separately man- 

 aged by U.S. federal and Alaska state 



agencies since 1998. The light-colored 

 deep form is captured in the offshore 

 trawl fishery and is the dominant spe- 

 cies of the pelagic shelf rockfish fisher- 

 ies complex regulated by the National 

 Marine Fisheries Service (NMFS). 

 Specific catch limits are set under the 

 designation "dusky rockfish." The oc- 

 casional catch of the dark form in these 

 offshore waters has also been consid- 

 ered "dusky rockfish." The dark-colored 

 shallow form is found commonly in the 

 nearshore jig fishery regulated by the 

 Alaska Department of Fish and Game. 

 The dark form, routinely misidentified 

 as S. melanops, may comprise up to 259c 

 of the catch in the "black rockfish" jig 

 fishery off Kenai Peninsula (Clausen 

 et al. 1 ) and is managed only as "other 

 rockfish" bycatch within the fishery. 



Early allozyme analyses (Tsuyuki 

 et al., 1965, 1968) indicated signifi- 

 cant genetic differences among samples 

 identified as S. ciliatus. A more detailed 

 analysis of several Sebastes species 

 (Seeb, 1986) and a later study focused 



1 Clausen, D. M., C. R. Lunsford, and 

 J. T. Fujioka. 2002. Pelagic shelf 

 rockfish. In Stock assessment and fish- 

 ery evaluation report for the groundfish 

 resources of the Gulf of Alaska for 2002, p. 

 383-417. North Pacific Fishery Manage- 

 ment Council, 605 W 4 th Ave, Suite 306, 

 Anchorage, AK 99501. 



