RESEARCH ARTICLE

Review of the labrid fishes of the Indo-Pacific Genus Pseudocoris, with a description of two new species

John E. Randall, Allan D. Connell & Benjamin C. Victor

Abstract

The Indo-Pacific labrid fish genus Pseudocoris Bleeker is represented by nine species: three pairs of sibling species that split between the Indian and Pacific Oceans and three endemic to various parts of the Pacific Ocean. Two of the species pairs include a new species for the Indian Ocean sibling. Pseudocoris heteroptera (Bleeker) is now considered limited to the Pacific Ocean, ranging from the Line Islands to Indonesia, north to Taiwan and southern Japan, and south to the Great Barrier Reef, while Pseudocoris occidentalis n. sp. is from the western Indian Ocean. The terminal male of both species have a large dark bar anteriorly on the body, followed by a series of irregular black bars; the Indian Ocean species differs by having shorter bars, a bright yellow anal fin in the terminal male, and the juveniles blue becoming yellow posteriorly. Pseudocoris yamashiroi (Schmidt) is now considered limited to the Pacific Ocean, wide-ranging from Japan, Taiwan, and the Marshall Islands, south to Samoa and New Caledonia, while Pseudocoris hemichrysos n. sp. is from the islands of the western Indian Ocean, including Maldives, Mascarenes, and Chagos; the terminal males of the new species differ by having a bright yellow-orange area on the rear upper body and soft dorsal fin. The third sibling-species pair had already been split; comprising the Pacific Pseudocoris bleekeri (Hubrecht) from Indonesia north to Ryukyu Islands, the terminal male with a broad bright yellow bar on midside of body, flanked by numerous dark bars and ovals, and Pseudocoris petila Allen & Erdmann, named for its slender body. The latter was described from two initial-phase specimens from the Andaman Islands, and an underwater photograph of the terminal male from NW Sumatra (the range is extended southwest to the island of Réunion and South Africa based on underwater photographs of terminal males); the terminal male of P. petila differs by having two yellow bars on the midside of the body. The three endemic Pacific species comprise Pseudocoris aequalis Randall & Walsh from the Coral Sea and southern Queensland, the terminal male bright blue without elongate anterior dorsal spines; Pseudocoris aurantiofasciata Fourmanoir, wide-ranging in the Pacific (with records in the eastern Indian Ocean at Christmas and Cocos-Keeling Islands), the largest species (to 193 mm SL), with the greatest body depth (to 2.9 in SL), the adult male with a narrow white bar on the side and with two long caudal-fin filaments; and Pseudocoris ocellata Chen & Shao from Taiwan and Japan, the terminal male with a large, irregular, blue-edged black spot on midside. Sequences of the barcode mtDNA COI marker for all but one species of the genus (P. ocellata is unavailable) show the eight species to be distinct monophyletic lineages, with the sibling-species pairs from different oceans diverging 0.63% in P. heteroptera/P. occidentalis, 2.51% in P. yamashiroi/P. hemichrysos, and 1.08% in P. bleekeri/P. petila.