Taxonomic revision of the genus Neoheligmonella Durette-Desset, 1971 (Nematoda, Heligmonellidae) parasitic in Muridae mainly from the Ethiopian Region

The genus Neoheligmonella Durette-Desset, 1971 (Nippostrongylinae) is revised and split into three genera, one of them with two subgenera. The new genera can be discriminated mainly by characters of the synlophe which had been not considered previously at the supraspecific level. These characters include the presence of a careen, the size of the right ridge relative to the left ridge, and the presence of gradients in the ridge size. The genus Neoheligmonella sensu stricto is proposed to include species with a careen, and it is divided into two subgenera: Neoheligmonella (Neoheligmonella) characterized by a right ridge measuring more than 45% of the ventral ridge of the careen, and Neoheligmonella (Duplantierus) n. subgen. with a right ridge measuring less than 45% of the ventral ridge of the careen. Dioufnema n. gen. includes one species with neither a careen nor hypertrophied ridges and having a bursa of type 1-3-1. Taranchonema n. gen. includes species without a careen, with the left ridge and the right ridge hypertrophied, and without a dorsal gradient in ridge size. A dichotomous key to the new genera and subgenera is provided. Five species of unknown synlophe, originally placed in the former genus Neoheligmonella and validated by other characters, are considered as Nippostrongylinae incertae sedis.