Further species of the opisthobranch genus Okenia (Nudibranchia: Goniodorididae) from the Indo-West Pacific

Abstract

Five new species of the nudibranch genus Okenia Menke, 1830 (Goniodorididae) are described from Australian waters and the anatomy of another ten species from Australia and the Indo-West Pacific are described. Okenia purpurata sp. nov. and O. vena sp. nov. are reported from northern New South Wales where they feed on the bryozoan Amathia tortuosa Tenison Woods, 1880. Okenia mellita sp. nov. is reported from New South Wales, and a pair of species, O. hallucigenia sp. nov.and O. stellata sp. nov. are reported from various locations in northern Australia where they both feed on the bryozoan Pleurotoichus clathratus (Harmer, 1902). Okenia virginiae Gosliner, 2004 is reported for the first time from Australia as is the Atlantic species Okenia zoobotryon (Smallwood, 1910). Anatomical information for O. barnardi Baba, 1937, O. hiroi (Baba, 1938) and O. mija Burn, 1967 is provided for the first time, as is further information on O. plana Baba, 1960 and O. pilosa (Bouchet and Ortea, 1983) from Australia and Hong Kong. New observations on the bryozoan prey of various species is reported: O. mija feeding on Amathia wilsoni Kirkpatrick, 1888, O. zoobotryon on Zoobotryon verticillatum (delle Chiaje,1828), O. hiroi on an unnamed species of Integripelta Gordon, Mawatari & Kajihara, 2002, O. plana on Membranipora membranacea (Linnaeus, 1767), Jellyella tuberculata (Bosc, 1802) and Cryptosula pallasiana (Moll, 1803). Okenia japonica Baba, 1949 and O. purpureolineata Gosliner, 2004 are reported feeding on the same unidentified species of Amathia Lamouroux, 1812.