A new quadrannulate species of Orobdella (Hirudinida,Arhynchobdellida, Orobdellidae) from central Honshu,Japan

A new quadrannulate species of Orobdella, Orobdellamasaakikuroiwaisp. n., from the mountainous region of central Honshu, Japan is described. This is only the second small species known within this genus, with a body length of less than 4 cm for mature individuals. Phylogenetic analyses using nuclear 18S rDNA and histone H3 as well as mitochondrial COI, tRNA^Cys, tRNA^Met, 12S, tRNA^Val, 16S, and ND1 markers showed that Orobdellamasaakikuroiwaisp. n. is the sister species of the quadrannulate Orobdellawhitmani Oka, 1895. Phylogenetic relationships within Orobdellamasaakikuroiwaisp. n. conducted using mitochondrial markers reveled a distinction between eastern and western phylogroups.