L. Forró szerk.: Miscellanea Zoologica Hungarica 10. 1995 (Budapest, 1995)
Gulyás, P., Bancsi, I.; Zsuga, V.: Rotatoria and Crustacea fauna of the Hungarian watercourses
of the rare species was found here (e.g. Cephalodella biungulata, C obvia, Encentrum oculatun, E. orthodactylum, Dicranophorus epipharis, Taphrocampha selenura, Trichotria curta). Abundance and biomass values indicate the presence of small to medium Zooplankton community. Many organisms indicate eutrophic and medium polluted water. Biomass varied between 0.03 - 0.92 g/m 3 . 19. Sebes-Körös Abundance of Zooplankton community is medium, biomass values are 0.01-1.57 g/m . The richest fauna among the Tisza tributaries was found here, characterized by the occurrence of 96 Rotatoria, 10 Cladocera and 1 Copepoda taxa, presence of rare species was also high compared to other streams. Besides planktonic elements, significant amount of metaphyton organisms was also found. In smaller proportion sediment dwelling species also occurred. Water quality of the river is generally acceptable, with occasional more polluted states. 20. Fekete-Körös Zooplankton abundance was medium, biomass values were between 0.05-2.19 g/m . Amongst the 68 Rotatoria and 6 Cladocera species planktonic, bottom dwelling, littoral and macrophyte vegetation inhabiting species can be found. Water quality of the river was mesotrophic, occasionally meso-eutrophic moderately polluted. 21. Fehér-Körös The plankton community of this particular stream was, both qualitatively and quntitatively, similar to the previous one. Biomass varied between 0.03 - 4.84 g/m 3 . Large values are due to Synchaeta kitina, Polyarthra dolichoptera, P. vulgaris and some Brachionus species. 22. Kettős-Körös The Zooplankton community of the river is variable, richer than those of the previous two Körös-stretch, indicated by the occurrence of 73 Rotatoria, 10 Cladocera and 1 Copepoda taxa. Abundance values of plankton communities indicate eutrophic conditions in summer (max. biomass 7.86 g/m 3 ) in spite of this, the water of the river is only moderately polluted. 23. Hármas-Körös At the upper river stretch the abundance is higher, biomass values are much greater here than near the confluence. At Gyoma, maximum biomass was 8.61 g/m 3 , while at Magyartés only 0.45/m 3 . Composition of the Zooplankton is variable; 70 Rotatoria, 11 Cladocera and 1 Copepoda taxa have occurred in the investigated period. Organisms of different habitat types occurred in similar proportions as at the other Körös-stretches. 24. Maros Among the Tisza tributaries the Maros is one of the most polluted one. Its fauna is characterized by cosmopolitan, adaptable, planktonic Rotatoria species. Both its Rotatoria and
