| biodiversity of parasites in freshwater environment in relation to pollution. | during 1994, 129 specimens of chub (leuciscus cephalus l.) from two localities, polluted--bolelouc, 80th river kilometer, near the city of olomouc, and unpolluted--brodské, 225th river kilometer, near the lanzhot on the morava river, were examined for metazoan parasites. altogether 38 metazoan parasite species including helminths, leeches and glochidia belonging to 14 genera were found, 34 in the case of unpolluted locality (brodské) and 28 in the polluted one (bolelouc). in both localities, 24 ... | 1997 | 9802067 |
| fish population size, and not density, as the determining factor of parasite infection: a case study. | the diversity and abundance of parasites vary widely among populations of the same host species. these infection parameters are, to some extent, determined by characteristics of the host population or of its habitat. recent studies have supported predictions derived from epidemiological models regarding the influence of host population density: parasite abundance and parasite species richness are expected to increase with increasing host population density, at least for directly transmitted para ... | 2004 | 15074879 |