Molluscan Diversity 3(2). December 2012

Original Articles

New records of Cecina manchurica Adams, 1861 (Gastropoda: Rissooidea: Pomatiopsidae) from the coasts of Nanao West Bay, Ishikawa Prefecture, Japan

Yuichi KAMEDA, Takuma HAGA and Hiroshi MINATO

Summary Cecina manchurica Adams, 1861 was newly discovered from four sites along Nanao West Bay and Notojima Island in Nanao Bay, Ishikawa Prefecture, which is located on the southernmost part of its distribution. This species inhabited among the decaying seagrass stranded on the artificial coasts such as stone or concrete revetment. Because the observed populations did not seem to be temporal, the present report raises importance of such artificial environment as potential habitat, which has not been emphasized for its conservation.

Key words: Endangered species, land snail, Noto Peninsula

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Distribution of the freshwater Asian clams Corbicula species in the Lake Biwa watershed, central Japan

Toru UCHINO and Tei KISHINO

Summary To confirm the distribution of invasive species of the freshwater Asian clam Corbicula fluminea (Mollusca: Bivalvia: Veneroidea: Corbiculidae) and native species of Corbicula leana was carried out at 200 stations in the whole areas of the Lake Biwa watershed (central Japan) in 2009. As a result, both Corbicula species (including Corbicula sandai) were collected at 137 stations. Corbicula fluminea was recognized at 120 stations scattering through the whole area of the Lake Biwa watershed, but C. leana was recognized at 30 stations inhabited by only C. leana being merely 17 stations, where limitted near around the Lake Biwa watershed. According to the previous study on Corbicula species in the Lake Biwa with neighboring waters, C. fluminea was not collected in earlier 1990 and the first record of this species was in 1998-2002. Present study indicates that native species of C. leana in the Lake Biwa watershed is immediately endangerd by invasion of C. fluminea.

Key words: Corbiculidae, river, canal, introduced species, conservation, Lake Biwa, Shiga Prefecture

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A new record of Mirus andersonianus (Enidae, Pulmonata) at Nakatonbetsu Town, Hokkaido Island, northern Japan

Yuta MORII

Summary This is the northernmost distribution record of Mirus andersonianus (Enidae, Pulmonata). Seven empty shells of M. andersonianus were collected at Nakatonbetsu Town, Hokkaido, northern Japan. It is assumed that M. andersonianus is still living at that place, because all collected shells had clear periostracum. This finding is very important biogeographically, because this is also the northernmost record of the family Enidae in Japan.

Key words: distribution, biogeography, Souya General Subprefectural Bureau

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Fossil terrestrial molluscan fauna including a new distribution record of Awalycaeus sp. (Alycaeidae) found in Saruda-do Cave, Kochi prefecture , Shikoku , Japan

Motohiro KAWASE, Yoshimasa HAYASE, Yusuke ANDO and Yuichiro NISHIOKA

Summary Twenty six species of fossil terrestrial molluscs were found in Saruda-do Cave. Saruda-do Cave is a limestone cave located at Hidaka village, Kochi Prefecture, Shikoku, Japan. Fossil terrestrial molluscan fauna of Saruda-do Cave has not been reported until now. The fossil molluscous construction is closed to the Recent terrestrial molluscan fauna in Shikoku Island. Two dominant species (Cavernacmella kuzuuensis and Bensonella plicidens) are indigenous around the Recent limestone areas. Awalycaeus sp. collected from fissure deposits at the 20 m depth of Saruda-do Cave below the ground surface, is considered an extinct new species with the 14C age of 32,750 ± 140 yr B.P.

Key words: Awalycaeus, fissure deposits

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Record of a rare species Katelysia japonica (Gmelin, 1791) (Bivalvia: Veneridae) from Wakayama Prefecture, central Honshu, Japan

Shin KUBOTA and Yasuo KOYAMA

Summary Three empty shells of a very rare bivalve species Katelysia japonica (Gmelin, 1791) was found from a mud flat in Uchinoura, Tanabe City, Wakayama Prefecture, central Japan. They are described and photographed. All the records of this species from Wakayama Prefecture since 2000 is summarized and reported here as the northernmost distributional knowledge.

Key words: distribution, global warming, mud tidal flat, Uchinoura, Tanabe city, Kii Peninsula

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Record of a rare species Charonia tritonis (Linnaeus, 1758) (Gastropoda: Renellidae) from Shirahama, Wakayama Prefecture, central Honshu, Japan

Shin KUBOTA

Summary A shell of a rare species Charonia tritonis (Linnaeus, 1758) that harbored a hermit crab Dardanus crassimanus (H. Milne Edwards, 1836) was found from Seto harbor, Shirahama, Wakayama Prefecture, central Japan in 2011. It is described and photographed.

Key words: rare species, distribution, hemit crab, Kii Peninsula

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The largest and the smallest adult shell of Cypraea (Maurita) arabica arabica (Schilder & Schilder, 1939) (Gastropoda, Cypraeidae) from Shirahama, Wakayama Prefecture, Japan

Shin KUBOTA

Summary The largest and the smallest adult shell of Cypraea (Maurita) arabica arabica (Schilder & Schilder, 1939) (shell length, 29-75 mm) (Gastropoda, Cypraeidae), that were collected from Shirahama, Wakayama Prefecture, Japan found between 1998 and 2012, are described and photographed. One of these specimens is reported here as the smallest shell in Japan.

Key words: individual variation, size, smallest record in Japan, cowry, Kii Peninsula, hermit crab

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