Abstract
Seasonal changes of periphytic smaller animals in Lake Kasumigaura, which has been hypertrophic, were investigated during the period of 1983 to 1984.
Species numbers of protozoa and metazoa in the total organisms attached on the biofilm-sheet were 156 and 28, respectively. The organisms were mainly divided into three types which were sessile, stoloniferous and free-swimming. Numbers of sessile type organisms decreased sharply in summer season, while stoloniferous type organisms increased in the season. It was suggested that the water of Lake Kasumigaura was α-mesosaprobic in summer and β-mesosaprobic in winter judging from saprobic system.
