Abstract
Seven species of the order Anseriformes (Mergus merganser, Melanitta nigra, Anas platyrhynchos, A. crecca, Aix galericulata, Cygnus bewickii, and C. cygnus), collected in Hokkaido, Japan, were examined helminthologically in order to obtain parasitic nematodes. A total of five nematode species was obtained. These were: Pseudocapillaria mergi (from A. crecca and C. cygnus), Contracaecum sp. (from M. merganser), Amidostomum anseris (from A. platyrhynchos, C. bewickii and C. cygnus), Tetrameres fissispina (from A. platyrhynchos), and Physaloptera sp. (from A. crecca). The records of both P. mergi and A. anseris were the first from Japan, while the records of T. fissispina and Physaloptera sp. involved new hosts. Among these five from Japan, while the records of T. fissispina and Physaloptera sp. involved new hosts. Among these five nematodes, A. anseris seems to be one of the most common occurring among the Anatidae of Hokkaido.
