抄録
Morphological and environmental's factor's characteristics of ciliated protozoa, the genus VorticeliaandPseudovoticellain entrophicated Lake Kasumigaura were studied. V.campanula and V.convallaria were often appeared in the lake through the yera. V. picta increased from winter to spring season, while V.vestita was often observed from spring to early summer. In the study of environmental factors, it was found thatV. campanulaand V.convallaria could inhibit at a high alkaline pH value 9.47, further V.vestita could do at allcaine pH value 8.74. From the result of the appearance of ciliates, the pollution level in Lake Kasumigaura was corresponded to α-mesosaprobic zone during summer, while inwinter β-mesosaprobic zone.
