ANALYSIS OF THE AMPHIPOD FAUNA OF CONTINENTAL RESERVOIRS IN THE NORTHWEST OF RUSSIA’S EUROPEAN PART

Abstract

The faunal composition of Amphipoda crustaceans of mainland water bodies in northwestern Russia is analyzed. To compile a checklist of amphipod species, data from original collections made in 1998–2021, the collections of the Zoological Institute, and literary information are used. To date, 29 species of amphipods have been recorded from the continental waters of the region. An arealogical analysis of the faunal composition reveals six groups or distribution patterns: Holarctic, West Palearctic, and North Atlantic estuaries, and further three groups of emigrants (settlers) from the Baikal-Siberian, Ponto-Caspian, and Arctic regions. The greatest species richness is recorded in estuarine sections of Baltic Sea rivers in the territories of the Leningrad and Kaliningrad regions, as well as fresh water bodies of the Republic of Karelia. In terms of species richness, estuarine species amphi-Atlantic in distribution and representatives of allochthonous faunas (invasive species) from the Ponto-Caspian basin dominate the region. The most common in the region are representatives of Holarctic and Palearctic patterns, as well as species of Arctic and Baikal-Siberian origins. Among them, the following species are most often to be recorded in lakes: Gammarus lacustris, Monoporeia affinis, Palaseopsis quadrispinosa and Gmelinoides fasciatus, vs G. zaddachi, G. oceanicus, G. tigrinus and Pontogammarus robustoides in estuarine brackish waters. Human-mediated introductions, both intentional and accidental, must have facilitated the appearance of invasive species in the fauna of Russia’s northwestern region. In the future, an increase in species richness in the region can be expected to occur in two ways: through the introduction of marine species into fresh waters and due to speciation.