Home – Home – Jornals – Contemporary Problems of Ecology 2003 number 3

The ecological factors playing an important role in the evolution of Baikalian amphipods are considered. The trophical factor causes a diminution of the size of animals and appearance of dwarf species.  At the same time, specialization with respect to food composition as an ecological factor is not widespread. The temperature factor tells on diffusion of Baikalian species to gulfs and sors, and on diel vertical migrations of benthos amphipods. The temperature and the illumination factors together determine the seasonal and circadian time course of the population structure and the change of the species composition of amphipods with respect to substrate, habitation depth, and in the littoral zone, as well as with respect to reproduction season. The parasite factor can give origin to small-sized and dwarf males in some Baikalian species, as well as increase the species diversity of deep-water nectobenthal amphipods. In the formation of the Baikalian deep-water side swimmers fauna a great role is played by regions with unusual geological conditions.