MACROZOOBENTHOS IN TRIBUTARIES OF THE LAKE IZRA

In addition to several periodic tributaries, the mountain lake Izra (488 above sea level) has two permanent ones of oligosaprobic character, differing considerably from one another by their physiognomy. Physico-chemical properties of both tributaries were similar, but tributary 1 showed smaller variations in the parameters studied. In both tributaries, benthic macrofauna consisting of 38 taxa was rather poor (Si = 56%) with Amphipoda as dominant representatives. The average yearly abundance of macrozoobenthos in tributary 1 and 2 was .hivin.x = 15 582.7 and .hivin.x 5 44.93 n m-2, respectively. Based on the occurrence of Amphipoda and Isopoda, a marked migration in the winter period can be presumed.