[Parasite fauna and features of the parasite community structure in the minnow Phoxinus phoxinus (Linnaeus) from Yenisei and Kacha rivers].

Phoxinus phoxinus is a species widely distributed throughout Palaearctic and is a good model for investigation of parasite communities. Species composition and structure of parasite communities in the minnow from the streams if different types, namely Yenisei river near Krasnoyarsk City and its left affluent Kacha River, were examined. Indices of Shannon, Simpson, and Berger-Parker were used to describe the component parasite communities. Twenty five parasite species of seven classes were revealed, and ectoparasite were found to be dominating among them. The host-specific parasite species Paratrichodina phoxini (Infusoria), Dactylogyrus borealis (Monogenea), Parahemiurus merus and Diplostomum phoxini (Digenea) constitute the peculiarity of the parasite fauna in minnow. Parasite community of minnow in the Kacha river is the most various one. It is caused by the following factors--favorable temperature conditions, composition of ichthyofauna, and a high density of fish population in the Kacha river. Metacercaria of Diplostomum phoxini, the specific parasites of minnow's brain, are dominating in both streams.