Morphoecological characteristics and feeding of wild rainbow trout Oncorhynchus mykiss (Walbaum, 1792) inhabiting the Krasnoyarsk Reservoir

Abstract

The paper provides information on the biological parameters and feeding of rainbow trout Oncorhynchus mykiss (Walbaum, 1792) that has entered the Krasnoyarsk Reservoir by escaping from fish farm cages. In the diet of the studied individuals, eleven groups of food components are found; imagoes of terrestrial insects and chironomid larvae dominate in ration. At the same time, studied individuals are characterized by slow linear and weight growth, low condition factor and stomach fullness, as well as a significant presence of non-food components in food boluses, indicating an insufficient supply of wild population with food resources. In addition, studied fish are characterized by a high degree of morphological malformations of the axial skeleton, which could affect their locomotor functions and ability to reproduce. Therefore, emergence of a self-reproducing population of rainbow trout in the Krasnoyarsk Reservoir is currently assessed as unlikely.

Keywords

• biological invasions
• rainbow trout
• reservoirs
• fish growth
• fish feeding
• morphological malformations