ICHTYOLOGICAL STUDY OF THE MIDDLE COURSE OF THE BE VA RIVER- LINKAGE BETWEEN FISH AND MACROZOOBENTHOS

Fish and macrozoobenthos of the Be va River were studied in summer and autumn 2000 and 2001. Electric fishing gear (Honda EX 1000, DC 230 V, 0.75-0.9 kW) was used for sampling. Four sampling sites (Grymov 19.6 r.kms, Rybá e 22.2 r.kms, Hustope e 50.7 and Choryn 54.7 r.kms) were selected. Quantitative samples of macrozoobenthos were collected in each site using a modified Surber sampler (box-type, 1400 cm2 coverage area and 150 Micron mesh size). Total of 23 fish species representing 5 families were determined. Family Cyprinidae with 15 species was the dominant and family Salmonidae, Balitoridae, Percidae and Gadidae were other recorded families. Fish species richness ranged from 9 at the Hustope e to 20 at Grymov localities. The lowest fish abundance and biomass was observed at the Hustope e (28.93 kg.ha-1 and 336 fish.ha-1) and the highest at the Choryn site (612.90 kg.ha-1 and 7367 fish.ha-1) respectively. Sum of 50 species of macrozoobenthos were determined in the River. Macrozoobenthos species richness varied from 4- 18. Biomass of macrozoobenthos varied from 0.08 - 11.7 gr.m-2 and abundance from 104- 1649 ind.m-2. Index of fish diversity varied from 0.811- 2.05 and equitability from 0.449 to 0.821 while this index for macrozoobenthos ranged from 1.1- 2.62 and equitability from 0.66- 0.94.saproby index also varied from 1.42 – 2.64 corresponding to -ezosaprobe.

Keywords:

Becva River , Ichthyology , saprobity , macrozoobenthos , Czech Republic