Dr. Holló Ferenc szerk.: Parasitologia Hungarica 4. (Budapest, 1971)

Parasit. Hung. 4. 145-156. 1971 Tapeworms (Cestodes) Parazitizing Eels Introduced into Lake Balaton Dr. Éva MURAI Zoological Department of the Hungarian Natural History Museum, Budapest In the frame of a compex research program concerning the fauna and the flora of the Lake Balaton, the research staff of the Hungarian Natural History Museum, in cooperation with the Hydrobiological Department of the Biological Research Institute of the Hungarian Academy of Sciences, Tihany, conducts systematic investigations on fish parasites. Until now, 441 fish specimens belonging to 16 species have been examined helminthologically. Besides investigations of the autochthonous fish species, the parasitic worms of 14 specimens of the introduced eel (Anguilla anguilla L.

) population have also been studied. The present paper is a report on the tapeworms parasitizing these specimens. Two internal parasitic worms have hitherto been reported from eels in Hungary: Bothriocephalus claviceps (Goeze, 1782) was found in eels of Lake Fertő and the River Tisza(EDELÉNYI, 1963, 1969)and of Lake Balaton and Lake Velence (MOLNÁR, 1966, 1970), while Acanthocephalus lucii (Müller, 1776) was also observed in the intestinal system of eels (MOLNÁR, 1970). Materials and methods One eel specimen was parasitologically examined on 26 September, 1967 and 13 further exemplars on 25 July, 1968. All specimens were dissected immediately after killing and the worms ex-