Redescription of Echinuria hypognatha Wehr, 1937 (Nematoda; Acuariidae) including ecology and new hosts

Reports on the presence of Echinuria hypognatha Wehr, 1937 in Europe have so far provided only general information, and therefore we present further morphometric and ecological characteristics of this parasite. In this study, the examined nematodes were isolated from the digestive tract of 1 005 wild ducks, representing 17 species from the northwestern Poland. The anatomical features of the parasite were in principle consistent with the description of the species by its discoverer and reports in the available literature. Nematodes (505 individuals) were found in 2.5 % of the examined ducks, in five species wintering in Poland: Clangula hyemalis, Melanitta nigra, M. fusca, Mergellus albellus and Aythya fuligula. The exclusive locations of the nematode were the glands in the proventriculus. The highest incidence was recorded in Melanitta ducks, and the presence of this nematode only in birds wintering in Poland indicates that E. hypognatha is brought to Poland by birds migrating from the areas of Eastern Siberia.