| Description |
The community of metazoan parasites of roach (Rutilus rutilus L.) in 13 different localities of the lower stretch of Morava River have been observed in spring and autumn 1997. We selected two types of study sites: oxbow lakes arised from original riverbed (Tvrdonice prostřední, Tvrdonice u chaty, Týnec malé, Týnec velké, Skařiny and moravská Nová Ves) and man-made gravel pits in the vicinity of the confluence of the rivers Morava and Dyje (Rohlík, Štrosflek, Melambon, Hvězda and Helpun). Roach originating from Rivers Morava and Kyjovka have been also investigated. Study sites Moravská Nová Ves and Rohlík have been observed every months (flood excluded). Altogether 357 roaches (Rutilus rutilus L.) have been examined and 23 species of metazoan parasites (Monogenea have been foundin 1997, namely: Dactylogyrus crucifer, D. fallax, D. nanus, D. rutili, D. similis, D. sphyrna, D. suecicus, Gyrodactylus carassii, G. gracilihamatus, G. laevis, G. prostae, G. vimbi, Paradiplozoon homoion; Digenea larvae: Diplostomum sp., Tylodelphis clavata, Posthodiplostomum cuticola, Cotylurus pileatus; Cestoda: Caryophyllaeus fennica; Acanthocephala: Acanthocephalus lucii; Hirudinea: Piscicola geometra; Lamellibranchiata: Glochidium sp.; Copepoda: Ergasilus sieboldi; Branchiura: Argulus foliaceus). Monogenea have been found most frequently (74% parasites records). 14% of parasite recorded belonged to Digenea - larvae, 6% to Lamellibranchiata, 5% to Crustacea. Less than 1 % of parasite specimens belonged to other taxonomic groups. Concerning two more intensively investigated study sites - Moravská Nová ves and Rohlík, G. vimbi showed the highest levelof mean intensity of infection in both of them. Mean intensity of infection at the study site Rohlík was twice higher than at the other site(Rohlík 34 parasite per host, moravská Nová Ves 15 parasite per host). Altogether 23 species of metazoan parasites at moravská nová Ves and 17 species at rohlík have been recorded.
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