Dr. Murai Éva szerk.: Parasitologia Hungarica 14. (Budapest, 1982)

ACHMEROV (1960) used both the designations T. hovorkai and T

, hovorkae in his original paper. The designation T. hovorkae must be regarded as an erroneously formed name, therefore the name T. ho vorkai should be accepted. At present T

.nikolskii is a wide-spread parasite in Hungary, occurring mainly in carp fry populations. Details of its development and pathology are given elsewhere (MOLNÁR /in press/). Data concerning the incidence of T. hovorkai are not satisfactory as this parasite has only recently been found in a single pond of a fish farm. However, taking into consideration that during our investigations special attention was always paid to the examination of the swimbladder, the incidence of this parasite cannot be frequent. At the time of our investigations T. hovorkai cysts were already in a advanced stage of development and contained only a few spores. Therefore, the appearance of dispersed spores in the macrophage centres of the kidney is not surprising. A similar phenomenon is freauently observed in the case of other myxosporean species developing in the inner organs. Few data are available on the host specificity of the two Thelohanellus spp.

, but according to our present knowledge both parasites seem to be strictly host-specific. The pathological significance of the two parasites is not known properly as yet. The distortion and breaking down of the fins by the growing cysts appeared to be the most serious pathological manifestation of the damage caused by T. nikolskii

. Although up to now no losses have been recorded, the cysts causing significant changes in appearance render the fish unmarketable. In order to clarify the pathological significance of the parasite developing in the swim bladder serosa further investigations are needed, T. hovorkai primarily has a differential diagnostical importance since it produces lesions at the same site where the lesions caused by swim bladder disease are localized

. In our opinion, because of irresponsible acclimatization of fish, the parasite fauna of the European common carp has increased by two new species, the pathological role of which is not yet completely known. Among the parasites introduced to Europe with the amur wild carp, after Dactylogyrus ach- merowi Gussev, 1955 and Khawia sinensis Hsü, 1935 (MOLNÁR, 1976; MOLNÁR and BUZA, 1975) Thelohanellus nikolskii and T. hovorkai have also become permanent pathogens of Hungarian fish farms

. ACKNOWLEDGEMENTS The authors thank dr. O. O. BAUER and dr. J. A. STRELKOV (Leningrad) for supplying the Russian literature and for their suggestions and dr. S.S. DESSER (Toronto) for reading and commenting on the manuscript. MOLNÁR, K. — XOVÁCS-GAYER, É.: Két távol-keleti származású Thelohanellus faj (Myxosporea: Myxozoa) előfordulása a magyarországi tógazdasági pontyokban Magyarországi tógazdaságokban tenyésztett pontyokon az elmúlt évben két, morfológiailag és lokalizációjuk tekintetében különböző Thelohanellus (Protozoa, Myxozoa) fajt találtunk. Thelohanellus fajok előfordulása korábban sem Magyarországon, sem pedig Európában nem volt ismert pontyokon. Európai vizekben való megjelenésük minden bizonnyal összefügg az amuri tőponty (Cyprinus carpio haematopterus) telepítésével. Ezt a ponty-alfajt az 1950-es években a Szovjetunió európai részébe telepítették, és hibridjei a "Kárpáton túli" területeken is megtalálhatók. A távol-keleti pontyokról ACHMEROV (1955,1960) öt Thelohanellus fajt írt le. Bár ezeket a fajokat SHULMAN (1962) a T.dogieli szinonimáinak tekintette, vizsgálataink alapján kétségtelenné vált, hogy az ACHMEROV által lefrt fajok létező,