FISHERY BULLETIN: VOL 79, NO. 2 



zacentrus was landed in Oregon from 1963 to 1971 

 but never in large quantities (Niska 1976), possi- 

 bly due to its reported preference for a rough bot- 

 tom (Gunderson^). 



Development of larvae and juveniles of S. en- 

 tomelas and S. zacentrus is described and com- 

 pared with other species of Sebastes for which 

 young stages are known. Occurrence of young off 

 Oregon is discussed. Additional new information 

 is presented on head spine patterns and variabil- 

 ity among the group of four similar species, S. 

 entomelas, S. flavidus, S. melanops, and S. mys- 

 tinus, which cooccur off Oregon. This information 

 will aid in identification and separation of these 

 species, particularly of specimens with variant 

 head spine patterns. 



METHODS 



Specimens described in this paper came from 

 collections in the School of Oceanography, Oregon 

 State University. Most collections were obtained 

 with 70 cm bongo nets, neuston nets, meter nets, 

 purse seines, Isaacs-Kidd midwater trawls, beam 

 trawls, otter trawls, and commercial midwater 

 trawls off the Oregon coast since 1961. Samples 

 were taken during all months of the year and 

 along the entire Oregon coast but were concen- 

 trated along an east-west transect off Newport, 

 Oreg. (lat. 44°39.1' N). Ben thic juveniles of S. en- 

 tomelas were taken from adjacent California 

 waters (lat. 40°12.2' N, long. 124°23.4' W). All 

 specimens were preserved in 5 or 10% Formalin^ 

 and transferred to 40% isopropyl alcohol. 



Our approach to identification, methods of mak- 

 ing counts and measurements, and terminology 

 for development and spination follow Richardson 

 and Laroche (1979) and Laroche and Richardson 

 (1980). Body parts measured include: 



Standard length (SL) = snout tip to notochord 

 tip preceding development of caudal fin, then to 

 posterior margin of hypural plate. 



Snout to anus length = distance along body mid- 

 line from snout tip to vertical through posterior 

 margin of hindgut at anus. 



•■Gunderson, D. 1976. Proceedings of the Ist rockfish survey 

 workshop. Processed rep., 14 p. Northwest Fisheries Center, 

 Nationtil Marine Fisheries Service, NOAA, Seattle, WA 98112. 



■■^Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



Head length (HL) = snout tip to cleithrum until 

 no longer visible, then to posteriormost margin of 

 opercle. 



Snout length = snout tip to anterior margin of 

 orbit of left eye. 



Upper jaw length = snout tip to posterior mar- 

 gin of maxillary. 



Eye diameter = greatest diameter of left orbit. 



Interorbital distance = distance between dorsal 

 margins of orbits. 



Body depth at pectoral fin base = vertical dis- 

 tance from dorsal to ventral body margin at base of 

 pectoral fin. 



Body depth at anus = vertical distance from 

 dorsal to ventral body margin immediately pos- 

 terior to anus. 



Caudal peduncle depth = shortest vertical dis- 

 tance between dorsal and ventral margins of 

 caudal peduncle. 



Caudal peduncle length = horizontal distance 

 from base of posteriormost dorsal ray to posterior 

 margin of hypural elements. 



Pectoral fin length = distance from base to tip of 

 longest ray. 



Pectoral fin base depth = width of base of pec- 

 toral fin. 



Pelvic spine length = distance from base to tip of 

 pelvic spine. 



Pelvic fin length = distance from base to tip of 

 longest ray. 



Snout to origin of pelvic fin = distance along 

 body midline to vertical through insertion of pel- 

 vic fin. 



Parietal spine length = distance along posterior 

 margin of parietal spine from insertion to tip. 



Nuchal spine length = distance along posterior 

 margin of nuchal spine from insertion to tip. 



Preopercular spine length (third spine; pos- 

 terior series) = distance from tip to basal insertion 

 if visible, or to a line connecting the points of 

 deepest indentation between preopercular spines 

 2 and 3 and spines 3 and 4 (posterior series). 



Longest dorsal fin spine = distance from base to 

 tip. 



Longest dorsal fin ray = distance from base to 

 tip. 



Longest anal fin spine = distance from base to 

 tip. 



All body lengths given refer to standard length 

 unless noted otherwise. When the two posterior- 

 most dorsal and anal fin rays arise from the same 

 pterygiophore, they are counted as one. 



232 



