Animal plankton of Lake Nikuru-numa, Hokkaido
1968 Volume 29 Issue 2 Pages 19-26
Details
1968 Volume 29 Issue 2 Pages 19-26
Zooplankton of Lake Nikuru-numa, Hokkaido collected on 25th October 1966 were studied. The results obtained are as follows.
1. Zooplankton was very rich. It consists of only 7 species, Acanthodiaptomus pacificus, Diaphanosoma brachyurum, Daphnia rosea and Keratella cochlearis var. macracantha being abundant.
2. It is noticeable that the individuals of Acanthodiaptomus pacificus, Daphnia rosea and Keratella cochlearis var. macracantha were markedly reddish brown colored.
3. The most abundant zooplankton was Daphnia rosea. More males were found than females.
4. The male of Alonella excisa was found for the first time in Japan.
