Elżbieta Bogacka-Kapusta, Izabela Jabłońska-Barna, Arkadiusz Duda, Grzegorz Wiszniewski, Andrzej Kapusta,
ABSTRACT. This article presents the results of a study of the dietary composition of juvenile Atlantic sturgeon caught in the Drwęca River and in Maltańskie Reservoir. Among the fish caught in the Drwęca, 67% had empty digestive tracts. In terms of numbers, the greatest share of the dietary composition of juvenile sturgeon from the Drwęca River was of Oligochaeta and larval Chironomidae, while the greatest weight contribution was made by larval Trichoptera. Larval Chironomidae, Oligochaeta, and Simuliidae were the most frequent components of sturgeon food. In comparison to the diet of fish from the Drwęca River, that of the fish caught in the Maltańskie Reservoir was more homogeneous as it was comprised exclusively of flies. Larvae of the genus Chironomus dominated numerically, followed by those of Procladius sp., Einfeldia sp., and Polypedilum sp. The analysis of juvenile Atlantic sturgeon food composition indicated that benthic organisms are the most important dietary component. In the natural lowland river the food spectrum of the juvenile Atlantic sturgeon was much wider than that of the fish in the dam reservoir.
Keywords: Atlantic sturgeon, food, benthos, frequency of occurrence, numerical share and weight share
Przyjęto po recenzji 26.07.2012 r.