Original Articles
The distribution of the pholadid Aspidopholas yoshimurai (Bivalvia: Myida) in Japan
Takuma HAGA
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Summary I document the distribution of Aspidopholas yoshimurai Kuroda & Teramachi, 1930, an endangered species sporadically recorded from Honshû and Kyûshû. Recent extensive field sampling identified two localities where many living A. yoshimurai occur on the western coast of Kyûshû. Some populations previously existed in Honshû but have apparently disappeared mainly due to reclamation even though specimens (in an overseas museum) appear to infer the presence of undiscovered populations in Chiba Prefecture on the Pacific coast of Honshû. This study has, for the first time, revealed what appears to be a stenotopic habitat preference of A. yoshimurai as so far it has been exclusively found living in a weakly consolidated, fragile sedimentary rock that is intertidally exposed at the margin of a tidal flat in a large, partially closed bay. This unique habitat is under threat of destruction (e.g. reclamation) so that conservation measures are necessary to protect it. |
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Key words: boring bivalves, substrata, sedimentary rock, estuarine environment, land reclamation, endangered species |
The first record of a population of Solenomphala debilis (Gould, 1859) (Caenogastropoda: Assimineidae) in the field of the Kanto Region, central Honshu, Japan
Masanori TARU
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Summary Live individuals of Solenomphala debilis, a possible introduced amphibious snail, were discovered from the Narashino Campus of Toho University, Funabashi, Chiba, Japan. This is the first record of this species in the field of the Kanto Region, eastern Japan. It is also the easternmost distribution record of the species in the entire Japan. These individuals were found on the wet ground surface in a fully terrestrial habitat which was discontinuous to any freshwater environments. They are likely to have been introduced unintentionally with garden plants and/or gardening apparatuses. It is anxious that the distribution range may expand rapidly in eastern Japan. |
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Key words: Rissooidea, land snail, introduced species, habitat, Kanto Region |
New records of non-marine molluscs of the Ishima Islands, Tokushima Prefecture, eastern Shikoku, with special reference to the occurrence of Smeagol sp. (Gastropoda: Pulmonata: Smeagolidae)
Hiroshi FUKUDA and Yuki TATARA
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Summary Thirteen species of non-marine molluscs are newly recorded from Ishima Island and neighboring Maeshima and Tanagojima islands, Anan City, Tokushima Prefecture, off eastern Shikoku: Freshwater species - Clithon retropictus; Supratidal species - Chevallieria sp., Truncatella pfeifferi, Laemodonta sp., Melampus nuxeastaneus, Microtralia acteocinoides, Smeagol sp.; Terrestrial species - Granulilimax cf. fuscicornis, Allopeas satsumense, Paropeas achatinaceum, Helicodiscus (Hebetodiscus) singleyanus inermis, Discoconulus yakuensis, Lehmannia valentiana. Although Chevallieria sp. and Laemodonta sp. were known from Kochi Prefecture in Shikoku, they are new to Tokushima Prefecture. Smeagol sp. is a member of the Smeagolidae which had been known only from New Zealand and southeastern Australia. Recently smeagolids were discovered from Amami Island, Kagoshima Prefecture and Kitagishima Island, Okayama Prefecture. The species of the present study is the third record of the family in the Northern Hemisphere. Nine individuals of the species were found under rocks of supratidal zone on a flat boulder beach of Tanagojima Island. |
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Key words: land snail, freshwater snail, rare species, supratidal, Anan |