Molluscs from Hydrothermal Vents and Cold Seeps in Japan: A ...

96T. Sasaki, T. Okutani & K. Fujikura12. Mesolinga soliditesta Okutani & Hashimoto, 1997[Japanese Name: Fukusuke-tsukigai]Mesolinga soliditesta Okutani & Hashimoto, 1997: 272, figs. 2-5; Matsukuma, 2000: 930 (pl. 463), fig.19, 931.Type depository: Holotype, NSMT-Mo 70967 (Fig. 6A-B).Type locality: Kanesunose Bank, 34˚17.6´ N, 138˚14.86´ E, 363 m (Shinkai 2000 Dive 816).Known only from the type locality.Type of habitat: Seep.Remarks: The species is tentatively assigned to this genus based on the cardinal morphology,the shape of the muscle scars and the smooth ventral margin (Okutani & Hashimoto, 1997).Genus Lucinoma Dall, 190113. Lucinoma yoshidai Habe, 1958[Japanese name: Yoshida-tsukigai-modoki]Lucinoma yoshidai Habe, 1958: 27; Okutani & Hashimoto, 1997: 277, figs. 19-25; Matsukuma, 2000:930 (pl. 463), fig. 15, 931. See Okutani & Hashimoto (1997: 277) for other references before 1997.Type depository: Holotype, NSMT-Mo 39858.Type locality: Off Shimane Prefecture, Sea of Japan, 35˚17´00´´ N, 132˚10´20´´ E, 146 m(Soyo-Maru station 495).Distribution record in JAMSTEC dives: Off Hatsushima, Sagami Bay, 830-1230 m (Fujikuraet al., 2002b).Other distribution records: Kii Peninsula and northwards, Sagami Bay, northeastern Honshu(Otsuchi Bay, Iwate Prefecture), Sea of Japan (off Shimane Prefecture), 100-200 m (Higo et al.,1999: B605).Depth range and type of habitat: 100-1230 m; seep and other reducing environments?Remarks: Although no living specimens were obtained in sites off Hatsushima, Sagami Bay,we regard this species as a member of chemosynthetic communities. Empty shells were collectedfrom among the Calyptogena beds (Fujikura et al., 2002b).Family Thyasiridae Dall, 1900Genus Conchocele Gabb, 186614. Conchocele bisecta (Conrad, 1849)[Japanese name: Ouna-gai]Type depository: Unknown.Type locality: Astoria, Oregon, USA (Miocene).Distribution record in JAMSTEC dives: Off Hatsushima, Sagami Bay, 830-1230 m (Fujikuraet al., 2002b).Other distribution records: Tosa Bay and northwards, Sagami Bay, Sea of Japan (off Tajima,Hyogo Prefecture), Hokkaido (off Cape Erimo), Alaska to Oregon, 4-1400 m (Higo et al., 1999:B619). Southern Bering Sea from Pribilof Islands, south to off Humboldt Bay, California, andfrom the Sea of Okhotsk to Hokkaido and the Sea of Japan, 50-750 m (Coan et al., 2000: 277).Depth range and type of habitat: 4-1400 m; seep.Remarks: In addition to publications on Recent molluscan fauna, there are numerous fossil