Lajos Vörös

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Picocyanobacterial abundance and their contribution to the total phytoplankton biomass, estimated as chlorophyll a, was investigated in 32 deep and shallow lakes. The lake series covered a wide range of natural and artificial lakes, from high altitude clear lakes and deep, large subalpine lakes through large shallow lakes, small reservoirs and fish ponds.(More)
Hutchinson's paradox of the plankton inspired many studies on the mechanisms of species coexistence. Recent laboratory experiments showed that partitioning of white light allows stable coexistence of red and green picocyanobacteria. Here, we investigate to what extent these laboratory findings can be extrapolated to natural waters. We predict from a(More)
Based on 388 parallel data of phytoplankton biomass and chlorophyll-a of two shallow lakes and two ponds, the following results were obtained: 1) Relative chlorophyll-a content of phytoplankton biomass varied between 0.08–1.88%; chlorophyll-a concentration showed great differences among lakes. 2) Significant correlations (r = 0.68–0.92) were established(More)
A comparison of the composition of natural phytoplanktoncommunities with the gut content of silver carp (Hypophthalmichthys molitrix) showed that this fish speciescan nottake up algae smaller than 10 µm. The species compositionofalgal assemblages in the gut content of the silver carpusuallydiffers significantly from the composition of the >10 µmsizefraction(More)
Sunlight penetration through the water column is controlled by the amount and kind of materials dissolved and suspended in the water. Understanding UV penetration in its complexity is essential for the prediction of the impact of UV radiation on aquatic ecosystems. However, only limited data are available on the penetration of UVR into shallow waters rich(More)
The effect of anatoxin (ANTX), the crude extract (AlgTX) and purified fraction (F1) isolated from cyanobacterium C. raciborskii was studied on the neurones of two snail species. ANTX and AlgTX exerted excitatory, inhibitory and biphasic effects on the spontaneous activity of identified neurones. Both ANTX and AlgTX elicited an inward current, which could be(More)
An insect test was developed to investigate the toxicity of cyanobacteria. The African locust, Locusta migratoria migratorioides R.F. was used as a test animal instead of mouse. The cyanobacteria tested were Aphanizomenon flos-aque, Anabaena aphanizomenoides, Cylindrospermopsis raciborskii, Microcystis aeruginosa. The toxicity of authentic microcystin-LR(More)
In order to explore the changes in the community structure of Lake Balaton in response to progressive eutrophication, the historic plankton database (1965–1990) was analysed, using the Zipf-Mandelbrot (ZM) model of dominance and diversity. Our results confirm differences in community organisation between the less eutrophic eastern (Siófok) basin and the(More)
Large lowland rivers with sufficient hydrological storage capacity are capable of supporting primary production, but the dynamics of the advecting phytoplankton is poorly understood. Our study aimed at exploring how longitudinal versus lateral connectivity, flow dynamics versus resource availability and continuous versus discontinuous environmental(More)
Picoeukaryotes dominate the phytoplankton of Lake Balaton—the largest shallow lake in Central Europe—in the winter period. We examined the annual dynamics of picoplankton abundance and composition in the lake in order to establish if the picoeukaryotes merely survive the harsher winter conditions or they are able to grow in the ice-covered lake when the(More)