DefinePK

Abstract

Control fish catches in the reservoirs of the Ural-Kushum water-irrigation system and the Derkul, Ankaty, Shiderta, Buldyrty, Utva, and Rubezhka rivers allowed the establishment of the extensiveness and intensity of infestation by the main helminth species among fish and the studied reservoirs. Ligulosis pathogens had the highest prevalence in the territory of West Kazakhstan region, found in 5 of 9 surveyed reservoirs, and postodiplostomosis in 4 of 9. Diseases were registered predominantly among carp family fish, and the extensiveness of infestation was 4.1 and 3.2%, respectively, of the total number of fish. The main species in which helminths have been detected are redfin, roach, and goose. Among anthropozoonotic diseases, in which fish are intermediate hosts, individuals with opistorchosis metacercariae were found in Derkul and Rubezhka rivers. The extensiveness of infestation was 16% of the carp population, which was significantly lower than the results of earlier studies. Of the other diseases dangerous to humans, no anisacid larvae were detected, which also did not agree with literature sources. Parallel to the parasitological examinations of fish, an examination of caught crayfish was carried out to determine the number of diseased crayfish. The survey revealed that about 20% of the river crayfish caught in the reservoirs had signs of rust-stain disease.