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

Kristiansen, J. ; Padisák, J.: Silica-scaled chrysophytes (Chrysophyceae and Synurophyceae) from the Kis-Balaton Reservoir, Hungary

monas spp. However, apart from the previously cited report, very little information is available on the algal flora in the reservoir (SCHMIDT & al. in press). When the samples of the present study were taken, surface water bloom was observed in the reservoir due to Planktothrix agardhii (GOM.) ANAGN. & KOM. and Limnothrix redekei (VAN GOOR) MEFFERT (identification by the participants of the 8th Workshop of the International Association of Phytoplankton Taxonomy and Ecology). Further details on the operational parameters, efficiency, etc. of the reservoir are available in POMOGYI (1991). METHODS Samples for EM chrysophyte studies were taken in the Kis-Balaton Reservoir on 9-10 July 1991 at 20 sampling stations (Fig. 10). Samples were fixed in Lugol's Iodine solution. The preparation of the silica structures was made from the Lugol-fixed samples. Drops of the material were placed on formvar+carbon coated grids by means of a micropipette. After drying, the grids with material were rinsed with distilled water for iodine crystals. The grids were examined in a Jeol-100-SX electron microscope. RESULTS AND DISCUSSION Eight species of scaled chrysophytes (Figs 1-9) were found during the investigations. Chrysophyceae 1. Chrysosphaerella annulata KRISTIANSEN & TONG (Fig. 1) - Described from eutrophic ponds in Austria and China; single scales also reported from various regions in the tropics (KRISTIANSEN & TONG 1989). New to Hungary. - Locality: No 15. 2. Paraphysomonas vestita (STOKES) DE SAEDELER (Fig. 3) - One of the most common and widely distributed chrysophytes. Cosmopolitan, found mainly in eutrophic localities where it may be the only chrysophyte occurring in any quantity (KRISTIANSEN 1985, 1988). Previously recorded from Hungary in EM (Hajdu 1975). - Localities: Nos 1, 2, 4, 6, 9,10,12,13,14,15, 20. 3. Spiniferomonas trioralis TAKAHASHI (Fig. 2) - A common species in many different types of water from oligotrophic to hypertrophic (ITO & TAKAHASHI 1982, KRISTIANSEN 1985, 1988, SIVER 1988). New to Hungary. - Locality: No 1. Synurophyceae 4. Mallomonas acaroides PERTY em. IVANOV var. acaroides (Fig. 7) - Widely distributed, mainly in eutrophic localities (KRISTIANSEN 1986, 1988, SIVER 1991) in contrast to var. muskokana NICHOLLS, which is confined to oligotrophic conditions (NICHOLLS 1987). Reported from many LM investigations in Hungary, but not to be trusted without EM. - Localities: Nos 1,13,19. 5. Mallomonas alpina RUTTNER in PASCHER (Fig. 4) - This is also a widely distributed species, cosmopolitan and occurring in a wide range of localities. Mainly in eutrophic, but also in hypertrophic lakes and ponds (KRISTIANSEN 1985, 1988, SIVER 1991). Some LM records in Hungary but not to be trusted without EM. - Localities: Nos 3,13. 6. Mallomonas tonsurata TEILING em. KRIEGER (Figs 5-6) - One of the most widely distributed species, cosmopolitan. Found in many types of water, most characteristically in eutrophic lakes and ponds (KRISTIANSEN 1985, 1988, SIVER 1991). Several LM records from Hungary. - Localities: Nos 1, 3, 6, 12, 13, 14,16, 19, 20.