抄録
Seasonal variations in the chemical components of the principal molluscs in Lake Biwa-ko, Corbicula sandai, Unio biwae, Hyriopsis schlegelii and Heterogen longispira, were studied. The chemical components were decreased during the summer in all the molluscs examined (Table 1-9). The contents of protein and glycogen exhibit the variations remarkably, while the lipid does slightly. That is, the protein and glycogen contents increased from December to May, and suddenly fell from July to August. In Corbicula sandai, the lipid contents reaches the maximum in May and decreases to the minimum in August. But, in the other molluscs, the lipid contents reaches the maximum in December and decreases to reach the minimum in August. The ash content of Corbicula sandai is less than a half of those of Unio biwae (1.8%) and Heterogen longispira(2.8%).
The calories of the soft part of molluscs were calculated based upon the contents of chemical components of their meat (Table 1-9).
