| Co-Investigator(Kenkyū-buntansha) |
ONOZATO Hiroshi Shinshu University, Faculty of Science, Professor, 理学部, 教授 (60273067)
HAYASHI Hidetake Shinshu University, Faculty of Science, Professor, 理学部, 教授 (60087129)
OKINO Tokio Shinshu University, Faculty of Science, Professor, 理学部, 教授 (50020681)
TODA Hideshige Shinshu University, Faculty of Science, Associate Professor, 理学部, 助教授 (60291382)
TAKATA Keisuke Shinshu University, Faculty of Science, Associate Professor, 理学部, 助教授 (90197096)
PARK Ho-don Shinshu University, Faculty of Science, Associate Professor (20262686)
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| Research Abstract |
The Japan Sea was changed from a freshwater lake to a sea ca. 10,000 years ago. This might separate the organisms in the lake into Japan and other countries facing the sea. It is expected, therefore, that they have developed in different ways between the countries, and that investigations on the distribution of the organisms help us with understanding how the freshwater biodiversity has been developed. In the present research project, we attempted to perform the investigations.
Animals of the crustacean genus, Gnorimosphaeroma, are distributed in various water bodies, freshwater lakes, blackish lakes and sea. We have found that some species survive in different habitats between Japan and Korea: e.g., G. naktongense, which inhabits freshwater bodies in Japan, have been collected only from brackish lakes in Korea, while G. chinense, which are common species in blackish lakes in Japan, have scarcely been found in the same environment in Korea.
In the investigation on freshwater Cladocera, three out of 28 species we collected from Korea have been found to be the species absent from Japan. The way of Cladocera to be distributed in such countries are discussed.
The isozyme analyzes of freshwater fish of the genus Pungitius collected from countries surrounding the Japan Sea have demonstrated that the blackish-typed animals of P. tymensis collected from the countries are in a genetic group, while that the freshwater-typed ones, which have been known to be in a genetic group, are divided into two groups. The results suggest that it is necessary to reconsider the distribution of the fish in East Asia.
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