Distribution of the Mass Species of Benthic Crustacean on Nearshore Slope the Ladoga Lake

Abstract

The species list and distribution of crustacean of a nearshore zone of the Valaam Island (Ladoga Lake) have been investigated by sampler-syringe, dredge and video records. On the depth 1–25 m the five species of crustacean: Asellus aquaticus (Linnaeus, 1758), Monoporeia affinis (Lindström, 1855), Pallaseopsis quadrispinosa (G.O. Sars, 1867), Gmelinoides fasciatus (Stebbing, 1899), Mysis relicta Lovén, 1862 were described. For the first time the vertical distribution of naturalized Baikal amphipods G. fasciatus were inventoried and their features of joint residence with local species were characterized. The distribution of the alien species reliably connected with wave intensity, types of grounds and depth range. The most numerous local species P. quadrispinosa distribution affects by depth range. The types of grounds do not influence on the quantity of all indigenous crustacean in the nearshore zone. In all condition the local species successfully compete with G. fasciatus. All these species inhabit of littoral have higher resistance for wave action as compared with non-indigenous species. It guarantees existence of refuges which can safe diversity of the indigenous species. The obtained data on the spatial distribution of crustaceans make possible to characterize the benthic communities of the little-studied parts of the littoral and sublittoral and, as a result, the food base of bentophagous fishes.