Description of two new species of Nippostrongylinae (Nematoda, Trichostrongylina, Heligmosomoidea) coparasites in Arvicanthis Ansorgei (Muridae) from Cameroon

Abstract

In the small intestine of a single Arvicanthis ansorgei from Cameroon, two new species of Nippostrongylinae were found: Neoheligmonella zera n. sp. and Heligmonina camerounensis n. sp. N. zera belongs to the Neoheligmonella species in which the right dorsal ridge is poorly developed. Among these species, N. bainae (Durette-Desset, 1970), a parasite of Steatomys opinus from Burkina Fasso, is a closely related species. It is differentiated by the presence of vulvar aloe, the ratio uterus length/body length and the separation of rays 2 and 3 at two thirds of their length. N. zera is also closely related to N. kenyae (Yeh, 1958) a parasite of Rattus rattus kijabius from Kenya by the pattern of the caudal bursa and the ratio spicules length/body length. The synlophe of N. kenyae was not described in detail but it is differentiated from N. zera by the position of the excretory pore, situated just posteriorly to the nerve ring and in the female by the ratio ovejector length/body length which is smaller. H. camerounensis n. sp. is characterised by the ratio dorsal ridges/ventral ridges which is 4/7. It is differentiated from the species of which the synlophe has not been described by the pattern of the caudal bursa (type 1-4 with tendancy 1-3-1). It is the first report of Nippostrongylinae species in Cameroon and the first record of a species of the genus Heligmonina in an Arvicanthis.