L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)
Gulyás, P., Bancsi, I.; Zsuga, V.: Rotatoria and Crustacea fauna of the Hungarian watercourses
dominance of several Rotatoria species the proportion of Ciliata and Zoogloea was also high indicating organic pollution. 13. Tarna Organic nutrient contents is medium, occasionally the river is polluted. Species composition is relatively poor, having 38 Rotatoria and 1 Cladocera taxa. Zooplankton is dominated by the pollution tolerant species (Brachionus angularis, Cephalodella gibba, Euchlanis dilatata, Keratella cochlearis, K. quadrata, Rotaria spp) and some rare species also occur (Brachionus bennini, B. plicatilis, Hexarthra fennica, Platyas quadricomis). Biomass values varied within one vegetation period between 0.01-2.34 g/m 3 . 14. Zagyva The river receives industrial and communal wastewater from many settlements, and also wastewater of sugar- factories. As a result of these, the species composition of Zooplankton community is not really rich. With regards to abundance values Rotatoria species occurred in larger proportion (Brachionus angularis, B. budapestinensis, Cephalodella spp, Colurella adriatica, Euchlanis dilatata, Filinia longiseta, Lecane spp, Rotaria spp, Synchaeta spp). The occurrence of Alona rectangula, Bosmina longirostris, Chydorus sphaericus, Daphnia pulex, D. magna, Peracantha truncata is worth noticing. Biomass values changed 0.01 - 4.51 g/m 3 . 15. Hortobágy Species composition of Zooplankton community is characteristic to slow flowing waters. Apart from the plankton elements, ratio of the organisms living on macrophyte vegetation was high (Cephalodella, Colurella, Dicranophorus, Epiphanes, Lepadella, Lophocharis, Mytilina, Platyas, Synchaeta, Trichocerca spp), within the Cladocera the metaphyton species (llioayptus agilis, Kurzia latissima, Scapholeberis mucronata, Simocephalus exspinosus) were characteristic. Qualitative composition of the communities and abundance values both indicate moderately polluted, eutrophic water quality. 16. Hortobágy-Berettyó Water quality and species composition is similar to the Hortobágy river, occasionally having larger species number and biomass values (0.14 - 2.47 mg/m 3 ). 17. Kösely One of the most polluted streams of the region. Rotatoria species dominated, but mass production of ciliates was also observed. Zooplankton biomass is medium to high, (0.21 - 5.67 g/m ), dominated by organic detritus feeders. 18. Berettyó Species rich community, variable species composition of Zooplankton community is characteristic that is indicated by the occurrence of 89 Rotatoria and 6 Cladocera taxa. Most
