Date of this Version
Taenia pencei n. sp. is described from the ringtail, Bassariscus astutus (Carnivora: Procyonidae), in western Texas, U.S.A., and its metacestode is characterized on the basis of specimens from Peromyscus cf. maniculatus in southern Oregon. Taenia pencei n. sp. apparently occurs exclusively in the ringtail, and it is the first cestode of the genus Taenia known from a member of the family Procyonidae. It is morphologically most similar to species of Taenia from mammals of the family Mustelidae in subclade two of the recently constructed phylogeny of that genus. Taenia pencei is distinguished from the nearctic Taenia taxidiensis in the badger Taxidea taxus; from the palaearctic Taenia martis occurring in members of the genus Martes and other mustelids in Europe; from the holarctic Taenia twitchelli in the wolverine Gulo gulo; and from the nominal species of small-hooked cestodes in mustelids (not including Taenia mustelae, in a different subclade), of which all but one have been described from members of the genus Martes. According to the concept presented in this study, those cestodes represent a single, holarctic species, Taenia cf. intermedia, synonyms of which, on grounds of priority, are Taenia sibirica and Taenia skrjabini, both described from Martes zibellina in Eurasia, and Tae. martis americana from Martes spp. in North America. Taenia melesi, from the Eurasian badger Meles meles, remains species inquirenda. Taenia pencei n. sp. is distinguished from all the aforementioned species by form and dimensions of rostellar hooks and by the arrangement and characteristics of genital organs. The holarctic occurrence of Taenia cf. intermedia appears to be a consequence of dispersals of mammals via Beringia during the late Pleistocene.