Visceral helminths of wild boars (Sus scrofa leucomystax) in Japan, with special reference to a new species of the genus Morgascaridia Inglis, 1958 (Nematoda: Schneidernematidae)

Abstract

Twenty-nine Japanese wild boars (Sus scrofa leucomystax), collected during the hunting seasons of 2005 and 2006 in the western part of the mainland of Japan (Honshu), were examined for their visceral helminths. Eighteen helminth parasites were prevalent in them, including 17 Nematoda species (Metastrongylus elongatus, Metastrongylus salmi, Metastrongylus asymmetricus, Metastrongylus pudendotechus, Stephanurus dentatus, Gnathostoma doloresi, Physocephalus sexulata, Ascarops strongylina, Capillaria suis, Ascaris suum, Globocephalus samoensis, Globocephalus longimucronatus, Strongyloides ransomi, Trichuris suis, Bourgelatia diducta, Oesophagostomum dentatum, and Oesophagostomum watanabei), and one Cestoda species (Pseudanoplocephala nipponensis). Muscle digestion of the diaphragm (using an artificial gastric juice) of 24 wild boars detected a single diplostomulum of probably Pharyngostomum cordatum. In addition, four female and six male adults of Morgascaridia kugii sp. n. (Nematoda: Schneidernematidae) were recovered from the large intestine of a single wild boar. Examination of an additional 20 samples of the stomach and 27 samples of the large intestine could not find this species. To date, recorded species of the genus Morgascaridia are limited to M. sellsi collected from wild boars in Uganda and Congo several decades ago, and thence, no records of the recovery are available. Morgascaridia kugii sp. n. differed from M. sellsi by smaller body dimensions, shorter distance between the precloacal sucker and the cloaca, smaller sizes of the copulatory spicules and the gubernaculum, and smaller sizes of uterine eggs.