Abstract
Forty-five Asiatic black bears, Ursus thibetanus, shot in mountainous areas of Gifu, Fukui, and Shiga Prefectures in central Honshu, the main island of Japan, between April 1991 and March Honshu were examined for nematode parasites. Three species of nematodes were found: Baylisascaris transfuga (Rudolphi, 1819) was found in 16 (39%) of 41 bears; Cercopithifilaria japonica (Uni, 1983) n. comb. [syn. Dipetalonema (Chenofilaria) japonica Uni, 1983] was found in two (4%) of 45 bears, and Dirofilaria ursi Yamaguti, 1941 was found in 22 (49%) of 45 bears. This is the first report on the prevalence of nematodes in black bears of central Honshu, Japan. The microfilariae taken from the uterine cavity of Dipetalonema (Chenofilaria) japonica females were sheathed. A close morphological examination of adults and microfilariae of D. (C.) japonica suggests that this filaria be placed in the genus Cercopithifilaria.
Key word: Nematoda; Baylisascaris transfuga; Cercopithifilaria japonica; Dirofilaria ursi; Asiatic black bears; Japan.