intestine of the fish, and the whole case disintegrates into separate sand 

 grains (Gerd, 1935:113—116, 142). The following whitefish include in their 

 diet Trichoptera: the Onega River (Coregonus lavaretus lavare- 

 toides, C. la va r e tu s lu doga, C. lavaretus widergreni), 

 C. lavaretus (C. la v a r e t o i d e s natio sunensis), C. lavaretus 

 maraenoides, C. lavaretus imandrae (Gerd, 1951 :90— 93; Kozhin, 

 1929:218-219; Krogius, 1926:151). 



Trichoptera are a constant, sometimes important, part of the food of 

 various whitefish in the Ob; Trichoptera take second place after Crustacea 

 in some localities in the diet of C.tugun during the foraging period; larvae 

 were found in the stomach of C.peled, C. muksun, C. nasus and the 

 C. lavaretus pidschian (Sal'dau, 1949:180-183, 1 89-192); Trichoptera 

 are constantly found in the stomachs of the Lake Teleteskoe whitefish 

 (C. lavaretus pidschian var. s m i 1 1 i)* in the upper reaches of the 

 basin; the stomach of some fish is filled with larvae of Apatania stig- 

 matella and Anisogamodes flavipunctatus (Solomonovskaya, 

 1952; Lepneva, 1949:110). Trichoptera are also part of the food of white- 

 fish in the Yenisei (isachenko, 1916:31-32; Romanova, 1948:154-174). 



Brachymystax lenok in Lake Teletskoe feeds avidly on Trichoptera, 

 which form about 80% of the food of this species; it may swallow to 

 72 large larvae of Dicosmoecus palatus (according to Solomonovskaya; 

 cf. Lepneva, 1949:111); Limnophilidae were found in the food of the lenok in 

 the Biryusa (a tributary of the Yenisei) (isachenko, 1916:10); in the Amur 

 and its tributaries, larvae of Trichoptera form about 16.5% of the food of 

 the lenok; 200 specimens are sometimes found in the stomach of this 

 species; the lenok swallows larvae of Stenopsyche griseipennis, 

 Arctopsyche amu r e n s i s, Hy d r op sy c h e n e va e, Hy d r o p sy ch e 

 sp., and species of Polycentropodidae, Psychomyiidae, Leptoceridae, 

 Limnophilidae and Sericostomatidae (Klyuchareva, 1952:367—369; Levanidov, 

 1951:75-76). 



Cyprinus c a r p i o, Rutilus rutilus, R. rutilus lacustris, 

 R. rutilus aralensis, Abramis brama and Leuciscus idus 

 feed on Trichoptera and other insects. Trichoptera constantly appear in 

 the food of Leuciscus leuciscus baicalensis in the Ob and 

 Yenisei. About 50% of the summer food of this consists of Trichoptera 

 in Lake Teletskoe (isachenko, 1916:60-63; Romanova, 1949:25-29; Sal'dau, 

 1949:204-211; Solomonovskaya, 1952:71-72; Spanovskaya, 1948:41-43; 

 Shevchenya, 1940:100-101). 



The food of Abramis brama in the Dzhezkazgan Reservoir in 

 Kazakhstan contains 0.5% larvae of Trichoptera in winter, 7.3% in spring 

 and 2.4% in summer (Malinovskaya, 1956:82). Several species of Cyprinidae 

 in Lake Kurgal'dzhin feed on the following Trichoptera: Cyrnus flavidus 

 Phryganea striata, Agrypnetes crassicornis, Oecetis i n - 

 tima. Trichoptera form 8.3% of the food of Carassius carassius, 

 17.8% of the food of C.auratus gibelio, 13. 3% of the food of Leuciscus 

 idus and 11.1% of the food of Rut ilu s rutilus; the percentage of 

 Trichoptera in the food of the preceding fish decreases in summer in 

 connection with the emergence of the spring generation of Trichoptera; the 

 percentage rises again in autumn (Tyuten'kov, 1956:157—164). 



These data apply to the large form of the whitefish which feeds in the littoral zone. 



166 



