Ecological analysis of the helminth fauna in Bufo bufo (Amphibia: Anura) from various habitats

Abstract

In this study is made an ecological analysis of the species composition, structure of the helminth community and the invasion degree of Bufo bufo in different habitats in the National Park «Smolny» (Republic of Mordovia, Russia). In 2018-2019, they were collected in five biotopes with different spawning water bodies. Nine helminth species were found, including five Trematoda species and four Chromadorea (Nematoda) species. There are two groups of species. The first of them develops on terrestrial nematodes Rhabdias bufonis, Oswaldocruzia filiformis, Oxysomatium brevicaudatum, rather common, regardless of the habitat, with a high degree of invasion and dominating in the helminth community. The species of the second group develop in aquatic nematode Cosmocerca ornata, as well as trematodes which are rarer, locally and with a low infection rate. They are typical parasites of green frogs (genus Pelophylax). The diversity of helminthes and the structure of their component community depend on the type, nature of the spawning water body and the presence of green frogs. Individuals of B. bufo, spawning in stagnant water bodies where green frogs live, have a more diverse helminth species composition, because there are helminths of the second group, whose development is related to the aquatic environment. The structure of their community is more complex. Bufo bufo, when using flowing water bodies without green frogs for spawning, has a depleted helminth composition and a simplified structure of their community. The obtained results have demonstrated the influence of one allotopic amphibian species on the formation of helminth community of another species under conditions of temporary syntopic occurrence.