Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 28. (Budapest, 1995)

© Hungarian Natural History Museum Parasit. hung., 28: 63-82, 1995 Hungarian Society of Parasitologists Parasitological survey of some important fish species of Lake Balaton Kálmán MOLNÁR and Csaba SZÉKELY Veterinary Medical Research Institute of the Hungarian Academy of Sciences, H-l 143 Budapest, Hungária krt. 21, Hungary (Received 10 September, 1995) Abstract: In the framework of a one-year survey, the parasitic infections of 299 specimens of the 15 economically and faunistically most important fish species of Lake Balaton were monitored. Seventy-one parasites species were identified to the species and 17 to the genus, and the data obtained on the parasites are reported. In Lake Balaton, the introduced eel parasite Anguillicola crassus can be considered the most prevalent parasite species. Besides the definitive host, it could be detected in several fish species acting as paratenic hosts. Occasionally a rather intensive Ergasilus sieboldi infection occurred on the pike-perch: both the gills and the operculum of the fish were covered by large masses of these crustaceans. Ichthyocotylurus metacercariae adhering to the pericardium of the pike-perch and the specimens of Tracheliastes maculatus colonising the body surface of the bream in the spring months seem to have pathological significance. Of the parasites found, Hoferellus carassii, Spironucleus elegáns, Paradilepis scolecina and Orientocreadium siluri are now reported from Lake Balaton for the first time. Key words: Protozoa (Mastigophora, Apicomplexa, Myxozoa, Ciliophora), Platyhelminthes (Monogenea, Cestoda, Aspidogastrea, Trematoda), Nemathelminthes (Nematoda), Annelida (Hirudinea), Mollusca (Bivalvia), Arthropoda (Crustacea), hosts: Stizostedion lucioperca, S. volgensis, Anguilla anguilla, Abramis brama, Carassius auratus gibelio, Neogobiusfluviatilis, Gymnocephalus cernuus, Silurus glanis, Pelecus cultratus, Blicca bjoerkna, Cyprinus carpio, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Tinea tinea, Aspius aspius, seasonal changes, parasite fauna, Lake Balaton INTRODUCTION Lake Balaton is the lake of the biggest water surface in Central Europe. It is important for Hungary as a site of both recreation and fishing. Because of its shallow water, Lake Balaton is extremely sensitive to environmental effects. Therefore, factors influencing the biological balance of the lake very often give rise to fish mortality. Although the parasite fauna of Lake Balaton fishes is relatively well studied, the fish mortalities observed in recent years call for more thorough investigations.