Abstract
Planktonic flora and fauna were investigated at the former Hachirogata Lake shore in 2006. A total of 131 species of planktonic microorganisms were recorded including 13 species of Cyanophyceae, 79 species of Protoctista (30 species of Chlorophyceae, 1 species of Ulvophyceae,17 species of Bacillariophyceae, 2 species of Sarcodina, 11 species of Mastigophora, 10 species of Cliophora), 27 species of Trochelminthes (20 species of Rotatoria, 1 species of Gastrotricha, 6 species of Nematoda), 8 species of Arthropoda (5 species of Branchiopoda, 3 species of Copepoda), 2 species of Tardigrada, 2 species of Oligochaeta. Dominant species appearing around aquatic plants were Sida crystalline, Alona quadrangularis, and Chydorus sphaericus. These Crustaceans especially related with communities of submergent aquatic plants such as Potamogeton maackianus and Cabomba caroliniana.
