Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 84. (Budapest 1992)

Gönczöl, J. ; Révay, Á.: Aquatic Hyphomycetes in softwater and hardwater streams of the Aggtelek National Park, NE Hungary

experiment (GÖNCZÖL 1989) and it was concluded that although this is a hardwater species (ROSSET & BÄRLOCHER 1985a, 1985b), its distributional feature is strongly influenced by substratum type, too. The present study provides further confirmation of this observation. The two canyon streams (Patkós, Kecskekút) definitely differ from the other six hardwater streams in strongly limited occurrence of Tricladium angulatum and almost total absence of Tetracladium marchalianum, and on the other hand, in the prevalent occurrence of some other characteristic species (Pachycladina mutabilis, Flagellospora leucorhynchos, Sigmoidea praelonga, Anavirga dendromorpha) which appear to be restricted to these streams. It is interesting to compare the distribution of Anavirga dendromorpha and Vargamyces aquaticus. Both species are well-known from the Morgó-stream, but they were never found together in the same section of the stream. The longitudinal distribution of Anavirga dendromorpha is restricted to the upper course of the Morgó-stream (softwater, lined by beech and hornbeam). Vargamyces aquaticus - a widespread species in Hungary (GÖNCZÖL et al. 1990) - during the present study was found in all hardwater streams on a variety of substrata. The two species were found abundantly sporulating together only on beech leaves and twigs obtained from the Patkós- and Kecskekútstreams. According to the present and earlier data Anavirga dendromorpha shows association rather with substratum type (beech) than habitat whereas Vargamyces aquaticus appears to be indifferent to leaf or twig types, but found with noticeable correlation to habitat. A noteworthy coincidence with MARVANOVA'S (1984) experience on the very low species number in foam of canyon streams with thick litter layer of beech was observed in the case of the Kecskekut-stream. Only 5 of 22 species were found in foam whereas the prevailing majority of the species occurred on varios substrata. Such marked difference, in species number found in foam and on natural substrata respectively, was not obtained in case of the other streams. This extreme example also suggests that more than one sampling method should be applied to get a complete picture about a stream. Additionally the parallel examination of leaf and woody substrata may provide especially useful information for substratum specificity of individual species. Acknowledgements - The authors are grateful to Dr. LUDMILA MARVANOVÁ for her kind help with identification and confirmation of some of our fungal samples and for her valuable comments and to Professor J. WEBSTER for the linguistic corrections. References ABDULLAH, S. K.. DESCALS, E. & WEBSTER, J. (1981): Teleomorps of three aquatic hyphomycetes. - Tram. Brit, mycol Soc. 77: 475-483. AIMER, R. D. & SEGEDIN, B. P. (1985): Some aquatic hyphomycetes from New Zealand streams. - New Z. J. Bot. 23: 273-299. ANDO. K. & Tu BAKI, K. (1984): Some undescribed hyphomycetes in the rain drops from intact leaf-surface. Trans, mycol. Soc. Japan 25: 21-37. BÄRLOCHER, F. & ROSSET, J. (1981): Aquatic hyphomycete spora of two Black Forest and two Swiss Jura streams. - Trans. Brit, mycol. Soc. 76: 479-483.