[Host specificity of nematodes in Poland].

Nematodes, which are the most diverse group of helminths in many aspects, constitute a good model for analysis of specificity. Among this group, we found monoxenous and stenoxenous species with a limited range of hosts and also oligoxenous and polyxenous species with a wide range of hosts. Order Oxyurida is represented mainly by monoxenous and stenoxenous species. The species from orders Strongylida, Spirurida and Ascaridida are characterized by all types of specificity while oligoxenous and polyxenous species are typical for capillariid nematodes (Enoplida). But some data show that the level of specificity is more determined by biology and ecology of host-parasite relationship than by taxonomic status.