C4
Endangered and alien species of terrestrial molluscs

Terrestrial snails encompass notable cases of endangered species in most areas of the world. Land snails are easily isolated geographically and differentiated into species endemic to small regions. The rate of endemism is especially high in small islands. In Japanese islands, ca. 700 species of land snails has been described so far. Most of island-dwelling land snails are listed as endangered species in a red data book or red list. The most famous case is land snails in Ogasawara Islands. They are threatened both by human environmental destruction and by coincidentally introduced alien predators. Extermination of the predators seems already too late, and widely spread alien predators are practically out of control. Eobania vermiculata originally from southern Europe was found in 2004 in Japan, representing the latest case of introduced land snails.　 (Takenori Sasaki)

References

Chiba, S. (1989) Taxonomy and morphologic diversity of Mandarina (Pulmonata) in the Bonin islands. Transactions and Proceedings of the Palaeontological Society of Japan. New Series 155: 218–251.

上島 励・岡本 正豊・斉藤 洋一（2004) 「新たな移入種、イスパニアマイマイ」『ちりぼたん』35: 71–74。