The helminthofauna of Rana arvalis Nilsson, 1842 (Amphibia: Anura) in the Republic of Mordovia

The helminthofauna of Rana arvalis Nilsson, 1842 in Republic of Mordovia is studied. It is revealed 23 species of helminths: Trematoda – 18 and Nematoda – 5. Dominating by quantity of types mature and larvae the Trematoda are characterized by low indicators of contamination and treat rare parasites of this host. Background parasites with high degree of the infection are geonematodes Rhabdias bufonis and Oswaldocruzia filiformis. They meet at Rana arvalis in all territory of the region; are less often distributed Cosmocerca ornata and Haplometra cylindracea. Distinctions in separate populations of amphibians are defined by different structure of trematodes and depend from character of a biotope.