| Co-Investigator(Kenkyū-buntansha) |
TAKATA Keisuke Fac. Sci., Shinshu Univ., Asso. Pro., 理学部, 助教授 (90197096)
YABE Mamoru Fac. Fish., Hokkaido Univ., Asso. Pro., 水産学部, 助教授 (80174572)
AMAOKA Kunio Fac. Fish., Hokkaido Univ., Pro., 水産学部, 教授 (50002085)
SAKAI Harumi National Fish. Univ., Asso. Pro., 助教授
|
|---|
| Research Abstract |
To elucidate the species diversity, taxonomic problems, syatematic zoogeography, morpho-ecological endemisms, reproductive systems, phylogenetic relationships and dispersal routes of coastal marine fishes and freshwater fishes in the Far East Russia, several expeditions were carried out in the Amur River, Lena River, Tumnin River and Peris Island during the three years from 1997 to 1999. Through the expeditions and laboratory works, following important findings were obtained. 1) The reproductive systems of some Cottid fishes belonging to the genus Pleurogrammus, Hemitripterus and Radulinopsis were found tobe non-copulating one by diving observations of their mating behavior. 2) An undescribed species of Zoarcidae was recorded from the coastal waters near Magadan, and another undescribed species of the genus Radulinopsis of Cottidae and the genus Eumesogrammus of Stichaeidae were also recorded from shallow sea areas of southern Premor'e. 3) The phylogenetic relationships among the species belonging to the genus Lethenteron, Tribolodon, Pungitius and Cottus were respectiveiy inferred from allozyme and mtDNA sequence data. 4) Within the genus Pungitius, two genetic clades (the Primor'e type and Skhalin-Okhotsk type) were newly detected from the freshwaters of Far East Russia. 5) The species of Lethenteron and Tribolodon are shown to have speciated around the Sea of Japan. 6) The two Cottid species, Trachidermus fasciatus and Cottus kazika , were shown to be monophyletic, suggesting that the Cottus species are not monophyletic but a paraphyletic group.
|
