Experimental assessment of the predatory pressure effect of gammarids on the structure of the macrozoobenthic community (Communicated by Academician Mikhail E. Nikiforov)

Alien amphipods were found in Belarus in the early 2000s. During long-term observations of the macrozoobenthic community in the rivers, a decrease of native amphipods was revealed in the southern part of Belarus. Several laboratory experiments were conducted to reveal the predatory effects of four alien species ( Dikerogammarus haemobaphes (Eichwald, 1841), Echinogammarus ischnus (Stebbing, 1898), Obesogammarus crassus (Sars, 1894), Obesogammarus obesus (Sars, 1896) on some macrozoobenthic groups. D. haemobaphes has a maximum predation rate and a broad food spectrum in comparison with other studied species. The above-mentioned data can be one of the reasons of wide spreading and very abandoned populations of D. haemobaphes in various rivers in Belarus.