Dr. Murai Éva - Gubányi András szerk.: Parasitologia Hungarica 29-30. (Budapest, 1997)

Dactylogyrus species may have occurred on the gills of bream; however, within the scope of this work it was simply impossible for us to collect and identify these parasites one by one from the gills which were sometimes infested by as many as several hundred monogeneans. Similarly, as Diplostomum spathaceum is known to be a collective species, parasites assigned to that species can be accepted as representatives of D. spathaceum only in the broad sense of the word. As we are aware of the shortcomings arising from the nature of the work performed, we have drawn moderate conclusions despite the large quantity of data obtained. Comparing the results of this study with those of a previous survey conducted by us on the parasite fauna of Lake Balaton fishes (Molnár and Székely 1995), it can be established that Kis-Balaton has a much less abundant fish parasite fauna than Lake Balaton, which can obviously be explained by the unsettled host-parasite and parasite-intermediate host relations. Kis-Balaton lacks some helminth species commonly occurring in Lake Balaton (e.g. Paradilepis scolecina), whose definitive hosts, cormorant, can be found in large numbers on the Kis-Balaton. The excellent general condition of the fish, probably resulting from the outstanding natural fish-food producing capacity of the new water space, may also contribute to the low level of the parasite fauna. At the same time, the frequent occurrence and high intensity of some parasites such as Goussia carpelli, G. leucisci and Hoferellus carassii raises the question whether these species play a role in the gibel carp losses recurring every year. A noteworthy point of interest is the detection of a hitherto undescribed Skrjabillanid-type nematode larva in carp lice parasitic on pikeperch, whose adults have so far been found in the swimbladder of Lake Balaton pikeperch only. Mention should also be made of the new Skrjabillanus species detected from the scales of wild carp, whose description is currently in progress. ACKNOWLEDGEMENTS The authors thank Ms Emese Papp for technical help rendered during the field trips and the fish dissections. Particular thanks are due to the fishermen of the Balaton Fisheries Co. Ltd. and personally to Mr. István Szabó, Unit Manager, and to his deputy, Mr. Zoltán Szabó for their help in the fish samplings. This work was supported by the National Research Fund (OTKA) of Hungary (project no. T 020044), the Fish Management Fund of the Ministry of Agriculture, and the US-Hungarian Joint Research Fund. Székely, Cs., és Molnár, K.: Előzetes tanulmányok néhány fontos halfaj parazita faunáján a Kis-Balaton I. Ütem Víztározójában A halak monitoring rendszerű parazitológiai vizsgálata 1996-ban kezdődött a Kis-Balaton felső víztározójánál (Hídvégi-tó). A szerzők 13 halfaj 100 példányából 50 parazita fajt mutattak ki. Ebből 20 Protozoa (1 Mastigophora, 5 Apicomplexa, 10 Myxosporea, 4 Ciliophora) és 30 pedig Metazoa (11 Monogenea, 4 Cestoda, 5 Trematoda, 6 Nematoda, 1 Annelida, 1 Mollusca, 2 Arthropoda) volt. A közölt parazita fajok közül 45 a Kis-Balaton parazita faunájára nézve újnak bizonyult. A leggyakoribb élősködő a Diplostomum spathaceum volt, amely alacsony intenzitás mellett sok halfajból előkerült. A madár-paraziták lárvái - annak ellenére, hogy végleges gazdáik nagy számban voltak jelen a vízrendszerben - a halakból még hiányoznak.