Four new species of Iponematinae (Drilonematidae, Drilonematoidea, Cephalobomorpha) parasitic in earthworms: Description and molecular affiliations

Three new species of Filiponema, Filiponema sp., and a new species of Iponema are described from earthworms. Filiponema champa sp. n., from the coelomic cavity of Pheretima sp. from Vietnam, is closest to F. cylindropharyngatum and F. javanicum but differs in having a wider body, longer spicules and more conspicuous excretory pore. Filiponema yaoense sp. n., from the coelomic cavity of Pheretima sp. from Vietnam, is differentiated from all valid species of Filiponema by its long, conspicuous excretory duct and a nerve ring situated more closely to the anterior extremity. It can be differentiated from F. champa sp. n. by a slimmer body, the more anterior position of amphids, circular vs transversely elliptical amphids and caudal organs, the wider tail tip, a shorter mail tail, longer eggs, smaller, straighter, spicules and a smaller gubernaculum. Filiponema suifunense sp. n., from the coelomic cavity of Drawida ghilarovi from Russia, is distinguished from all known species of the genus due to the presence of narrow, projecting lateral fields. Filiponema sp., from the coelomic cavity of Lumbricus friendi from France, is described but not named due to lack of material. Iponema visayanum sp. n., from the coelomic cavity of Megascolecidae gen. sp. from the Philippines, can be distinguished from I. tonkinense by its longer spicules and pharynx and its larger amphids situated further from the anterior extremity than in I. tonkinense. D2-D3 LSU sequences were obtained for I. visayanum sp. n. and F. suifunense sp. n. and compared with homologous sequences of other Drilonematoidea nematodes.