Diversification of Cercopithifilaria species (Nematoda: Filarioidea) in Japanese wild ruminants with description of two new species

Twelve of the 17 Cervus nippon nippon deer from Kyushu Island, Japan, that we examined were infected with one or two Cercopithifilaria species. C. longa n. sp. adults were in the subcutaneous tissues of limbs and the abdomen, and C. crassa n. sp. adults were in the skin, mainly in the anterior part of the back ; the distribution of the dermal microfilariae generally matched that of the adult worms. The two new species were assigned to the group of primitive Cercopithifilaria species that parasitize ruminants (bovids and cervids), but the new species could readily be distinguished from others morphologically. C. longa was more primitive and resembled C. bulboidea, one of the five species from the serow Capricornis crispus, a Japanese member of the Caprinae, and species from Bovidae in Africa. C. crassa had a thick body and large spicules like C. rugosicauda from Capreolus capreolus in Europe, the only previously known Cercopithifilaria species from cervids, but it also had one or two hypertrophied pairs of caudal papillae, an unusual character found so far only in Japanese parasites. Among the 12 species known from ruminants, four are African, one is European and more highly evolved, and seven are Japanese, with some being primitive and some more evolved. The great diversity of Cercopithifilaria species in the two wild ruminants that live in Japan seems to have resulted from local speciation, which occurred during the Pleistocene, from a primitive form of the C. longa type derived from Eurasiatic ancestors, which has disappeared or, more probably, not yet been discovered. Dans l'île de Kyushu (Japon), 12 des 17 Cervus nippon nippon examinés sont parasités par une ou deux espèces de Cercopithifilaria. C. longa n. sp. est situé dans le tissu sous-cutané des pattes et de l'abdomen, C. crassa n. sp. dans la peau, principalement dans la région antérieure du dos ; la distribution des microfilaires dermiques suit celle de leurs adultes respectifs. Les deux nouvelles espèces appartiennent au groupe primitif des Cercopithifilaria qui est parasite des ruminants (bovidés et cervidés), mais elles sont bien différentes l'une de l'autre. C. longa est plus primitive et ressemble aux espèces parasites des Bovidae en Afrique ainsi qu'à C. bulboidea, une des cinq espèces parasites du Caprinae japonais, le sérow Capricornis crispus. C. crassa a un corps épais et de grands spicules comme C. rugosicauda, parasite de Capreolus capreolus en Europe et unique espèce connue auparava