Taenia arctos n. sp. (Cestoda: Cyclophyllidea: Taeniidae) from its definitive (brown bear Ursus arctos Linnaeus) and intermediate (moose/elk Alces spp.) hosts

Taenia arctos n. sp. (Cestoda: Cyclophyllidea: Taeniidae) is described from the brown bear Ursus arctos Linnaeus (definitive host) and moose/elk Alces spp. (intermediate hosts) from Finland (type-locality) and Alaska, USA. The independent status of the new species and the conspecificity of its adults and metacestodes have been recently confirmed by the mtDNA sequence data of Lavikainen et al. (2011; Parasitology International, 60, 289–295). Special reference is given to morphological differences between the new species and T. krabbei Moniez, 1879 (definitive hosts primarily canines for the latter), both of which use the moose/elk (Alces spp.) as intermediate hosts (the latter also uses Rangifer and perhaps other northern ruminants), and between the new species and T. ursina Linstow, 1893, both of which use the brown bear U. arctos as a definitive host. New morphological data are also provided for adults and cysticerci of T. krabbei. The analysis includes potentially useful morphometric features that have not been previously applied to Taenia spp.