A limnological survey of Nakano-umi and Lake Sinji in the coast of the Japan Sea

II. On the plankton of Nakano-umi in summer (1949)

Abstract

This investigation were made in the summer of 1949 in the whole region of Nakano-umi which could not be researched last year. In research of 1948 the plankton species have been found 53, but 85 species were found in this time.
The increase of the plankton seems to be mainly due to the fact that we researched the region of the Japan Sea also.
Zooplankton is superior to phytoplankton in species but less predominant in amount. Diatoms are the most abundant among the phytoplankton, 25 species have been found.
The Copepoda and Cladocera are the most important in the zooplankton of this lake. As the important species we can show the following: Rhizosolenia semispina, Thalassiothrix nitzschioides, Haemiaulus Hauchii, Chaetoceras decipiens, Leptocylindrus danicus, Nitzschia seriata, Ceratium fusus, Pyrophacus horologicum, Oithona nana, Penilia schmackeri, Evadne tergestina. Most of these usually distributed on the coast of Japan Sea.