Revision of the genus Eustrongylides Jägerskiöld, 1909 (Nematoda: Dioctophymatoidea) of piscivorous birds

Abstract

The genus Eustrongylides Jägerskiöld, 1909 (Nematoda: Dioctophymatoidea) is revised based on examination of adult E. tubifex from experimentally infected Common Mergansers (Mergus merganser) and specimens of Eustrongylides spp. from various museums. Only three species are considered distinguishable: E. tubifex (Nitzsch in Rudolphi, 1819) Jägerskiöld, 1909 (the type species), E. ignotus Jägerskiöld, 1909, and E. excisus Jägerskiöld, 1909. All three species are redescribed. Eustrongylides perpapillatus Jägerskiöld, 1909 is regarded as a synonym of E. tubifex. Eustrongylides formosensis Sugimoto, 1933, E. indicus Ali, 1971, E. phalacrocoracis Johnston and Mawson, 1941, E. plotinus Johnston and Mawson, 1941, E. tricolor Sugimoto, 1931, and E. excisus amoyensis Hoeppli, Hsü, and Wu, 1929 are regarded as synonyms of E. excisus. Nine additional species are considered species inquirendae.