Orr and Matarese: Revison of the genus Lepidopsetta Gill, 1862 



555 



(iorsal midline; a series of melanophores present from the 

 gut along the ventral midline posterior to anus to just pos- 

 terior to ventral stripe of posteriormost bar; a few melano- 

 phores on the caudal peduncle and above and below the 

 notochord tip. 



Distribution 



The genus is endemic to the North Pacific and is wide- 

 spread on the continental shelf (Figs. 6-13). Its range 

 extends from Yongil Bay, Korea, in the southern Sea of 

 Japan and along the northern coasts of Japan, north 

 through the Sea of Okhotsk and the Bering Sea, the most 

 northerly record being from the Gulf of Anadyr and the 

 vicinity of St. Lawrence Island. It is recorded from the Aleu- 

 tian Islands and into the eastern North Pacific throughout 

 the Gulf of Alaska, south into Puget Sound and along the 

 west coast of Washington. Oregon, California, and Mexico. 

 Its most southerly record in the eastern Pacific is from the 

 Cortez Banks of Baja California, Mexico. 



Larvae of the eastern North Pacific species range from 

 the Bering Sea and Aleutian Islands along the Pacific coast 

 to Baja California (Figs. 12-13). Both species co-occur in 

 the eastern Aleutian Islands to the Washington coast; only 

 larvae of L. polyxystra n. sp. have been routinely collected 

 from the Bering Sea and only lai-vae of L. bilineata have 

 been collected from California and south in California 

 Cooperative Oceanic Fisheries Investigations (CalCOFI) 

 samples. A subset of larvae collected by AFSC surveys in 

 the Gulf of Alaska and Bering Sea was examined to com- 

 pare differences in temporal distribution and mean den- 

 sity ( number/10 m-'; Appendix Table 1 ). During the 22-year 

 sampling period, larvae of L. polyxystra n. sp. appear first 

 in our March collections (Table 14). whereas lai-vae of 

 L. bilineata first appear in April. The largest catches of 

 L. polyxystra n. sp. occurred in May, whereas the largest 

 catches of L. bilineata occurred in June. Overall, in the 

 subset of cruises from 1972 to 1994 considered in our 

 study. L. polyxystra n. sp. were more abundant and mean 



density was higher (5.34/10 m-) than that of L. bilineata 

 (0.414/10 m2). 



Habitat 



Species of the continental shelf were collected over sand 

 and gravel, commonly at depths of 200 m and less, to as 

 deep as 575 m (Allen and Smith, 1988). For eastern North 

 Pacific species, highest densities of larvae were found over 

 depths of less than 500 m, although they were also col- 

 lected over deeper water. 



Life history 



Described eggs of Lepidopsetta are demersal, off-round, 

 and have a sticky chorion, causing them to adhere to each 

 other or to a substrate, and range in size from 0.86 to 

 1.08 mm in diameter (Yusa, 1958; Pertseva-Ostroumova, 

 1961; Penttila, 1995). The reproductive season extends 

 from winter to early summer, generally earlier in southern 

 species, and spawning occurs at depths of less than 220 

 m. All sexually mature Lepidopsetta apparently migrate 

 from shallow shelf areas in the fall to deeper upper slope 

 waters during winter and migrate back into shallower 

 shelf waters during spring and summer. Immature Lepi- 

 dopsetta remain in shallow waters throughout the winter 

 and migrate into shallower coastal waters in the spring 

 and summer. 



Garrison and Miller ( 1982) provided a summary of repro- 

 ductive characteristics of Lepidopsetta from the western 

 and eastern Pacific Ocean, which included L. bilineata and 

 L. polyxystra n. sp. Blackburn (1973) described the ich- 

 thyoplankton from Skagit Bay, Washington, located in the 

 northernmost region of Puget Sound and included descrip- 

 tions and illustrations of larvae ofLep^dop.st'f/n. The Wash- 

 ington Department of Fisheries (WDF) has reported eggs 

 of Lepidopsetta (L. bilineata or L. polyxystra n. sp.. or both ) 

 from late December through early March in sandy gravel 

 of upper intertidal beaches in several sites in central and 



