Zoobenthos communities at stony beach of Lake Baikal. 1 - Fauna.

摘要

Samples of zoobenthic animals were collected on stony beaches of Lake Baikal, Russia, for 1.5 years. Abiotic factors affecting zoobenthos were revealed. 30 species of benthic animals belonged to Turbellaria, Hirudinea, Oligochaeta, Polychaeta, Bathynellacea, Amphipoda, Isopoda, Collembola, Plecoptera, Trichoptera, Chironomidae, Mollusca, Diptera larvae, Coleoptera larvae, and Acarina were found. The animals found on the beaches were divided into 3 ecological groups. The 1st group consists of species occasionally found, brought there by storms from deeper parts of the lake. The 2nd group comprises animals migrating onto the beach during still periods when they are not disturbed by waves or other animals coming there for egg laying. The 3rd group includes obligatory beach dwellers adapted to the increased hydrodynamic activity. The obligatory beach dwellers are represented by 2 species complexes: amphibionts and hydrobionts. A similar composition is characteristic of moraine supralittoral. The supralittoral complex of Lake Baikal is suggested to be formed due to annual regular fluctuations of the water level and the great length of shoreline.