抄録
Investigations on the age-composition, body length l, weight w and depth, and the quality indicator, 1000 w/l8, of carps and of crucians from the three lakes mentioned in the title lead to the conclnsions: -
(1) That all carps experimented were two years old and in their growth rate, lake Kizaki, being of eutrophyc type, was superior to the other two.
(2) The age composition of crucians was normal in lake Kizaki, but abnormal in the other lakes. Such abnormality seems to have bearings on the variation in catch and in the number of snowy days during the year when each year class was hatched. Dimensions of the body were poor in lake Nakatuna, while the quality indicator was low in the oligotrophyc lake Aoki.
