Neureclipsis bimaculata is found more rarely, and Macronema 

 radiatum was not found in the Irtysh. Aethaloptera rossica was 

 found only in the upper reaches of the river, near Semipalatinsk, where it 

 occurred in large numbers (Martynov, 1934:303-304; Fridman, 1937:203-211) 



Species which occur also in rivulets in the foothills are common on the 

 bottom of the Yenisei, with its rapid current and its numerous rapids; this 

 also applies to Arctopsyche ladogensis and Hydropsyche 

 nevae, which are distributed in small numbers to Stony Tunguska. From 

 the village Oznachennyi to the estuary of the Angara, 2—4 specimens per m 

 of H. nevae were found; further downstream, to Stony Tunguska, only 

 0.9 specimens per m were found. 

 124 Among the stream elements, single specimens of Rhyacophila impar 

 and Lepidostoma hirtum were found on the banks of the river . 

 Neureclipsis bimaculata does not occur in the Yenisei; larvae of 

 Hydropsyche ornatula and Brachycentrus subnubilis have 

 been found in the upper, middle and lower reaches of the river, to Igarka and 

 Kureika. The following Siberian and Far Eastern potamobionts predominate 

 in the Yenisei: Hydropsyche kozhantshikovi, Cheumatopsyche 

 czekanowskii, Macronema radiatum and Aethaloptera 

 rossica. Only single specimens of H. k ho z h ant sh ik o vi reach the 

 estuary; the other species reach the Lower Tunguska. On stones near the 

 banks of the river occur: Apatania sp., L e p t o c e r u s a nn ul i c o r n i s, 

 L. excisus, Goera sajanensis (Greze, 1957:155 — 156; Lepneva, 

 1948b:67-97; 1949:255-261; Pirozhnikov, 1929:68-72). 



The fauna of Trichoptera of the Amur is very characteristic, both in its 

 large numbers and in the occurrence of a number of species which occur 

 only in this river. The larvae of these species have been little studied; 

 none of the three typical potamobionts of European rivers were found in the 

 Amur. Identification of adult insects showed that the group of potamobionts 

 of the Amur consists of 9 species of Annulipalpia, including 2 species of 

 Polycentropodidae not known from other localities (Hyalopsyche 

 amurensis and Neucentropus mandjuricus), Arctopsyche 

 amurensis, Cheumatopsyche chinensis, Ch. albofasciata, 

 the widely distributed Ch. czekanowskii and 3 species of Macronematinae: 

 Amphipsyche proluta, which is common in the Amur, the very common 

 species Aethaloptera rossica, and the less common Macronema 

 radiatum. The last 4 species are known from the Amur also as larvae; 

 especially numerous larvae of A e thai op t e r a rossica were found in 

 the stomach of fish. The water temperature in the habitats of the larvae 

 reaches 22—23.6° in summer; the number of larvae of Aethaloptera 

 rossica reaches 1 80—266 specimens per m ; in some localities, that of 

 Amphipsyche proluta to 40 specimens per m . Larvae of Hydro- 

 psyche sp. have also been recorded from the Amur; larvae of Oecetis 

 sp. and Leptocerus excisus (Leptoceridae) were found on the banks 

 of the river (Klyuchareva, 1952:362-367). 



Reservoirs 



The building of a reservoir slows the current of a river, disturbs the 

 hydrological regime of the river section and changes the character of the 



116 



