Environmental Aspects of Organization of Multi-Species Groups of Fish Larvae in Littoral of the Rybinsk Reservoir

Abstract

The paper presents the results on the study of specific, spatial-temporal, age and trophic structures of groups of fish larvae feeding in the littoral zone of the Rybinsk Reservoir. The species composition and distribution of fish larvae were determined in biotopes of the protected vegetated coastal area in years of different water content. It has been pointed out that the dynamics of zooplankton in the spring period corresponds to the age-related changes in consumption of different groups of hydrobionts by fish larvae. There have been investigated the environmental factors ensuring the dissociation in time and space of potential competitors of the same trophic level accompanied by the divergence of food spectra and the division of food resources. Using as the example one of the structural and functional elements of the littoral biocenosis (multi-species groups of fish larvae), the role of the trophic factor which provides the organization and functioning of this biological system and gives it a balanced and integral character has been demonstrated. At the same time, the balance of food relationships was provided by such mechanisms as differentiation of individuals of different species of fish larvae according to the age principle, change of food objects during ontogenesis, and spatial separation.