Feeding of juvenile sterlet (Acipenser ruthenus, Acipenseridae) in the Danube River midstream

Abstract

The present paper provides the results of the study on feeding of juvenile (underyearlings and age 2+) sterlet (Acipenser ruthenus) caught in the Danube River in 2002–2003. The full spectrum of food items found in the fish stomachs was identified. The seasonal patterns of food composition are revealed. It is shown that juvenile sterlet in the Danube feeds mainly on larvae of chironomids and trichopterans, amphipods, and leeches. The organisms typical for lithophilic and lithorheophilic biocenoses play considerable role in the feeding of sterlet. Mean daily gains of body length and weight in the sterlet underyearlings are calculated.