Observations on Food-organisms of a Teleost, Hypomesus olidus Pallas

Abstract

Observations were made from August, 1933 to July, 1934 on the content of alimentary canal of a teleost, Hypomesus olidus, and plankton organisms living in its habitat, Lake Kasumigaura Pref. Ibaraki. The fish feeds mostly on such kinds of small animals as are found most abundantly in the lake. Bosmina and Neomysis are numerous therein all year round and eaten by the fish irrespective of the seasons. In March and April a small insect, Simulium crassitarsis is abundantly found in the digestive canal, in summer Sida, Limnocalanus, fry of several fishes and larvae of shrimps (See Table 1).