Adatok a Baláta-tó algaflórájához

Halász (1943) és Uherkovich (1978) 177 faj előfordulását közölte a Baláta-tóból. 1991-ben, valamint 1995-1996-ban végzett vizsgálataink során további 137 taxon került elő, melyek közül számos faj egyúttal Magyarország flórájára nézve is új. A flóra különösen gazdag Desmidiales és Synurophyceae fajokban. A talált fajok egy része kizárólag savas vizekben, lápokon fordul elő, mások kevésbé specializáltak, sőt néhány alkalikus, hipertróf vizekből is előkerül. Mindezek alapján a Baláta-tó átmeneti lápnak minősíthető. Vizsgálataink megerősítik Boros (1924) századeleji megállapítását, amely szerint a Baláta-tó és a Rétyi Nyír (Erdély, Kovászna megye) között igen nagy a florisztuikai hasonlóság

Preridiniopsis Kevei SP. nov., A new freshwater dinoflagellate species (peridiniceae, dinophyta) from Hungary

This paper reports results from light and scanning electron microscopic study of a freshwater dinoflagellate considered as a new species for the science, Peridiniopsis keveisp. nov. It was found during the last ten years in different lake, rivers, canals in Hungary and some European countries. it frequently appeared as a water-bloom forming species. The theca morphology and and plate structure analysis of this dinoflagellate established its identity as a new species. P. kevei Grigorszky et Vasas is discussed in the paper in comparsion with related taxa, moreover data about its occurrence and ecology

Green algal flora of the acidic bog-lake Baláta-tó, SW Hungary

Algal flora in the acidic bog-lake, Balata-to were sampled twice in 1991 and bimonthly in 1995-1997. Balata-to is a Nature Reserve of diluvial origin with interesting and rare higher plant species and associations. Previous algological investigators demonstrated the presence of 177 algal taxa and recognized the uniqueness of its microscopic flora. During our observations 231 taxa were found, 105 of them belonging to Chlorophyta (Volvocales 16, Chlorococcales 46, Desmidiales 41, Ulotrichales 2). The present paper gives a brief survey of the rare and characteristic chlorophytes of the lake

The Effects of Temperature, Nitrogen, and Phosphorus on the Encystment of Peridinium cinctum, Stein (Dinophyta)

For avoiding the unfavorable environmental conditions several aquatic microorganisms are capable of forming specialized resistance cells like akinets, hypnospores, statospores, etc. Recognition of the important role of cysts in the life cycles of dinoflagellates increased the need to study their role in the ecology of phytoplanktons, and this, combined with the knowledge of chemical and biological characteristics of the water, may lead to a better understanding of the spatial and temporal dynamics of dinoflagellates. This paper reports on the effects of temperature, nitrogen, and phosphorus on the percentage of encystment of the dinoflagellate Peridinum cinctum Stein. The phosphorus content of the medium affected encystment only at the highest temperature applied (22 degrees C). Nitrogen content and temperature were the most important factors controlling the encystment

Importance of acidic phosphatase activity in P supply and Gonyostomum semen Ehrenbergh (Raphidophyta) occurrence in a Hungarian peat bog, Keleméri Kis-Mohos (Ne Hungary)

Phosphatase enzymes are capable of releasing phosphate through cleavage of phosphoester bonds. The seasonal importance of this process was examined by using a model substrate paranitrophenylphosphate and the Michaelis-Menten equation to estimate the release rate of PO4-P from phosphomonoesters. The seasonal occurrence of phosphomonoesters and acid phosphatase activity was used to estimate the velocity of phosphate release from these compounds. Filter fractionation of phosphatase activity demonstrated that most activity (>60%) was in size fractions less than 0.45 μm. The release rates were highest in May and June (15 to 25 nmol L–1 min–1) during the Gonyostomum semen (Raphidophyta) bloom and decreased to less than 2 nmol L–1 min–1 in two weeks and remained low throughout the summer and the fall. Fractionation of 32P-H3PO4 labelled dissolved organic phosphorus showed this fraction to vary considerably through the year. Potential phosphate release declined through the summer and into the fall. Significance of the co-occurrence of phosphomonoesters and acid phosphatase activity maxima and Gonyostomum semen (Raphidophyta) bloom is discussed