The Rate of Feeding and Digestibility of the Freshwater Mussel, Hyriopsis schlegelii, Determined with Crude Silicate as an Indicator

Abstract

The present study was undertaken to clarify the filtering rate and digestibility of the freshwater mussel, Hyriopsis schlegelii, with the crude silicate as an indicator. The observations were made in Lake Biwa during the water temperature 5.5-22.7℃. The results obtained were as follows : 1) Approximate estimation of filtering rate from crude silicate method was 4.3∿15.8 l/one mussel/one day. 2) The filtering rate increases according as the water temperature increases. 3) The feeding rate (as dry matter) ranges from 78.7∿361.2 mg/one mussel/one day. 4) The digestibility was 45% (range from 34∿66%).