539 Abstract.-The endemic North Pacific pleuronectid genus Lepidopsetta Gill is revised to include three species: L. hilineata (Ayres), L. polyxystra n. sp., and L. mochigarei Snyder Adults of L. biliiieata can be distinguished by a low gill-raker count and high supraorbital pore count; larvae may be distinguished by four dorsal midline nielanophores, heavy finfold pigment, a short snout-to-anus length, and a deep body. The species ranges from Baja California to the eastern Aleutian Islands and the extreme southeastern Bering Sea. Adults of L. mochigarei are distin-guished from all other members of Lepidopsetta by higher scale and pre-opercular pore counts and lower gill-raker and supraorbital pore counts. Larvae are similar to larvae of L. hilin-eata but can be distinguished by their postanal pigpnient pattern and melano-phores on pectoral-fin rays. Lepidopsetta mochigarei ranges from the southern Sea of Okhotsk to Korea. Adults of L. polyxystra n. sp. are diagnosed by a high gill-raker count and low supraorbital pore count; larvae are diagnosed by two dorsal midline nielanophores, light fin-fold pigment, long snout-to-anus length, and a slender body. The species is found from Puget Sound through the Bering Sea and Aleutian Islands to the Kuril Islands, overlapping with L. hilineata from the extreme southeastern Bering Sea to Puget Sound and with L. mochi-garei in the southern Sea of Okhotsk. Synonymies, diagnoses, descriptions, and geographic distributions are pro-vided for adults and larvae of all species; keys are provided for adults. Descrip-tions of early juveniles of eastern North Pacific species are also presented. Under the name of L. hilineata . L. polyxystra n. sp. has been the subject of many studies of eastern North Pacific Lepidopsetta . All previous studies of specimens from the southeastern Bering Sea into Puget Sound should be considered applicable at the generic level only, unless voucher specimens are verifiable. Revision of the genus Lepidopsetta Gill, 1862 (Teleostei: Pleuronectidae) based on larval and adult morphology, with a description of a new species from the North Pacific Ocean and Bering Sea James W. Orr Ann C. Matarese Resource Assessment and Conservation Engineering Division Alaska Fisheries Science Center National Marine Fisheries Service, NOAA 7600 Sand Point Way NE Seattle, Washington 98115-0070 E mail address ((or J W Orr) James Orr g'noaa gov Manuscript accepted 22 February 2000. Fish. Bull. 98:539-582 (2000). The flatfishes (Pleuronectiformes) of the eastern North Pacific Ocean constitute a major component of the commercial fisheries of the region. In the Bering Sea, which encompasses the largest fisheries resource of the United States, the rock soles of the genus Lepidop-setta are the second most abundant flatfishes and the third most abundant commercial groundfish species, second only to yellowfin sole (Limanda aspera) and walleye pollock (Theragra chalco-gramma) (NMFS. 1999). At the species level, eastern North Pacific pleuronectids have been con-sidered well known. Nearly all species were recognized and described during the latter half of the 1800s. primarily through the activities of California ichthyologists. Among the names that remain valid, the last species to be described was Limanda sahkalinensis Hubbs, 1915, although in the western Pacific Microstomus shiintovi Borets, 1983, was most recently described from the northwestern Hawaiian ridge. How-ever, these earlier works were based on adult morphology, and only recently has a knowledge of the ontogeny of these species been acquired. Among the descriptions of early life history stages of eastern North Pacific pleuronectids, one morphological form could not be traced to a recognized species. Exami-nation of this form led to the following revision of the genus Lepidopsetta. Four nominal species have been de-scribed and allocated to the genus Lep-idopsetta: Platessa hilineata Ayres, 1855a, was described from San Francisco mate-rial, and apparently without the knowl-edge of Ayres' slightly earlier description, a specimen collected near Puget Sound was described as Platichthys umbrosus Girard, 1856. Gill (1862) erected Lepi-dopsetta to contain Platichthys umbrosus and later (1864) indicated that Platessa hilineata Ayres, 1855a. was allied and perhaps congeneric. Lockington (1879b) published a redescription of L. umbrosa, describing the misidentified new species Isopsetta isolepis (Lockington, 1880a), which he ultimately removed from Lep-idopsetta to his new genus Isopsetta (Lockington, 1883). In his description of Lepidopsetta isolepis,he treated Platich-thys umbrosus Girard as a synonym of L. hilineata. Nearly 20 years after Gill's erection of Lepidopsetta, Cope (1873) described Pleuronectes perarcuatus from Alaska, later considered a synonym of L. hilineata by Jordan and Gilbert (1881). Jordan and Evermann (1898) considered each of these nominal species members of Lepidopsetta and further as synonyms of L. hilineata, although they recognized the northern popula-tions ("Puget Sound and northward") as L. hilineata ujnbr-osa. Finally, Japanese Lepidopsetta were described by Snyder (1911) as L. mochigarei and Jordan and Hubbs (1925) considered all Japanese Lepidopsetta to be representatives of this species. More recently, the genus has been en-visioned as containing either two spe-
Revision of the genus Lepidopsetta Gill, 1862 (Teleostei: Pleuronectidae) based on larval and adult morphology, with a description of a new species from the North Pacific Ocean and Bering Sea
BioStor
