摩周湖, 阿寒パンケ湖および豊似湖の底生動物相の研究

抄録

Three lakes in Hokkaido, Mashu-ko, Akan-Panke-ko and Toyoni-ko were investigated in 1974 with regard to their bottom fauna. In lake Mashu-ko, Micropsectra sp. A, though not abundant, occurred in the zone shallower than about 100 m. In the profundal zone deeper than 160 m, no macroscopic animals were found, except for the very rare occurrence of Procladius sp. F. This lake belongs to an oligotrophic-Tanytarsus lake. In Akan-Panke-ko, Sergentia sp. B was found in the profundal zone deeper than 40 m and Calopsectra sp. J in the zone shallower than 40 m. Though this lake belongs to an oligotrophic-Tanytarsus lake, slight eutrophication is in progress. In Toyoni-ko, Sergentia sp. B was abundant in the profundal zone, except at the central part deeper than 17 m. In the central part of the lake where the dissolved oxygen content was measured to be 8.4%, only Tubifex sp. was found. This lake belongs to a mesotrophic-Sergentia lake.