Establishment of the Baikalian Amphipod Gmelinoides fasciatus (Amphipoda, Crustacea) in Lake Onega

摘要

The number of biological invasions has recently increased drastically all over the world (Carlton, 1991). This problem is especially important for European aquatic ecosystems where invasive' species often bring about considerable reconstruction of natural communities (Invasive Aquatic Species of Europe, 2002). The amphipod Gmelinoides fasciatus (Stebbing) of Baikal origin was introduced into some Russian water bodies to increase their fish productivity. In most these water bodies, G. fasciatus becamea mass species, displacing from littoral communities other amphipod species, including the previously dominant Gammarus lacustris Sars (Panov and Berezina, 2002). In the late 1980s, the Baikalian amphipod was found in Ladoga, the largest European lake,and in 1994, in Beloe Lake (Panov, 1994; Shcherbina et al., 1997). Since these lakes are connected to Onega Lake by the Svir' River and the Volga-Baltic Canal (Fig. 1), there is the possibility of G. fasciatus becoming established in Onega Lake, with accompanying changes in communities. The dispersion speed of G. fasciatus is known to be considerable. For example, in the Volga basin, this amphipod successfully colonized in 20 years water bodies situated 300-400 km upstream from the introduction site. Tolerance of G. fasciatus to various abiotic factors may also facilitate rapid dispersion (Berezina et al., 2001; Berezina and Panov, 2002).