Dr. Murai Éva szerk.: Parasitologia Hungarica 24. (Budapest, 1991)

fluviatüis), derived from the same habitat, was found to be free from infection even when large numbers of specimens were examined. In the development of S. danubialis the renal stage is preceded by a blood stage similarly as was reported for cyprinids (Csaba 1976; Lom et al. 1983; Bas ka and Molnár 1989). This is yet another finding to support the theory that the extracellular blood stages designated C blood protozoa or UBO are a developmental stage of sphaerospores. Up to now Hedrick et al. (1988) and Lom et al. (1989) have been the only investigators to demonstrate blood stages from non-cyprinid fishes infected by renal sphaerospores: from Gasterosteus aculeatus and Lepomis gibbosus, respectively. Despite the intensive infection of the fish examined, in this study no striking pathological lesions apparent by visual inspection could be seen. This is in contrast to the data of Pronin and Pronina (1985) who observed substantial swelling of the kidney in perch infected by S. pectinacea. ACKNOWLEDGEMENTS The author thanks Dr. F. Baska and Dr. Cs. Székely for help in collecting the fish and Ms. Emese Papp for the drawings. Molnár K : Sphaerospora danubialis sp. n. (Myxosporea: Sphaerosporidae) édesvízi sügérfélék veséjéből A Sphaerospora danubialis sp. n. gyakran előforduló élősködő dunai selymes durbincsban (Gymnocephalus schraetzer), vágodurbincsban (G. cernua) és fogassüllőben (Stizostedion lucioperca). A vesetubulusokban talált spórák morfológiailag különböznek a S. markewitschi és S. pectinacea spóráitól, melyeket ugyancsak édesvízi sügérfélékből mutattak ki. A tubulusokban élő sporogóniás stádiumok mellett selymes durbincs véréből a presporogoniás stádiumok is kimutatásra kerültek. REFERENCES Baska, F. and Molnár, K. (1989): Blood stages of Sphaerospora spp. (Myxosporea) in cyprinid fishes. - Dis. aquat. Org. 5: 23-28. Bocharova, T. A. and Donetz, Z. S. (1974): New species of myxosporidians (Myxosporidia, Cnidosporidia) from fishes of the Wasjugan basin (in Russian). - Para zitologiya 8:14-16. Csaba, G. (1976): An unidentifiable extracellular sporozoan parasite from the blood of the carp. -Parasit, hung. 9: 21-24.