Description of a New Species of Branchiobdellida (Annelida: Clitellata) and Comparison with Other Cirrodrilus Species in Northern Honshu, Japan

Abstract

A new species of ectosymbiotic branchiobdellidan, Cirrodrilus iwakiensis sp. nov., is described from Cambaroides ja- ponicus (de Haan, 1849), the endemic freshwater Japanese crayfish, collected in Aomori Prefecture, northern Honshu Is- land, Japan. The anatomical features used to identify C. iwakiensis are compared with those of its closest congener, C. nip- ponicus (Yamaguchi, 1932), as well as C. aomorensis (Yamaguchi, 1934) and C. tsugarensis Gelder and Ohtaka, 2000 distrib- uted in the same region.