Scientific publications

Intraspecific variability of the cestode, P. longicollis was studied from three host species, the Nelma (Stenodus nelma), the Lenok (Brachymistax lenok), and the Malma (Salvelinus malma) of fish order Salmoniformes. Host forms of helminthes were found to be similar in intrapopulation diversity and in the proportion of rare forms evaluated by polymorphious features of the scolex shape and sexually mature segments. Hostal differences in morphophysiological traits, such as the attachment, trophics and reproduction, were revealed. The parasites from Nelma are shown to phenotypically be the most diverse. These forms show the maximum heterogeneity of diversity and distribution frequencies. The conclusion is drawn that the helminthes respond to changes in the habitat conditions in the host predominantly by plastic traits.