Nematode fish parasites in the Danube River – Belgrade section.

Abstract

Parasitic species of freshwater fishes represent a large group of organisms including either adults or larval stages. Macroparasites - Nematode (round worms) infect many different species of aquacultured and wild fish. Adult forms are typically found in fish digestive tract. The present work covers the investigation of nematode parasites of fish from the Belgrade section of the Danube River. During ichthyoparasitological study have been collected and examined 22 freshwater fish species from families Cyprinidae (14), Esocidae (1), Percidae (4), Centrarchidae (1), Gadidae (1) and Siluridae (1). A total of 802 fish specimens have been examined and 54.86% were infected. In intestine of 12 infected fish species have been found 9 species of Nematode parasites - Hysterothylacium bidentatum (Linstow, 1899), Contracaecum siniperca (Dogiel & Achmerov, 1946), Contracaecum sp. juvenile (Railliet & Henry, 1912), Cammalanus lacustris (Zoega, 1776), Cammalanus truncatus (Rudolphi, 1814), Camallanus sp. juvenile (Railliet & Henry, 1915), Philometra rischta (Skrjabin, 1923), Rhabdochona denudata (Dujardin, 1845) and Rhabdochona hellichi (Šrámek, 1901). During investigation, species Philometra rischta has been marked off (“heat parasite”), infesting a four fish species (Blicca bjoerkna, Leuciscus idus, Perca fluviatilis, Sander lucioperca) with prevalence of infestation 1-17. Fish species with great number of nematode parasite in intestine was Lota lota (four), while other were infected with one or two parasites.