A new species of medicinal leech in the genus Hirudo Linnaeus, 1758 (Hirudiniformes, Hirudinidae) from Tianjin City, China

Abstract

Medicinal leeches in the genus <i>Hirudo</i> have been utilized for therapeutic procedures for thousands of years. To date, six known species of <i>Hirudo</i> are widely distributed in different regions of the Eurasian continent. In this study, a new medicinal leech species <i>Hirudotianjinensis</i> Liu, <b>sp. nov.</b> is described based upon specimens collected from Tianjin City, China. The new species can be distinguished from its congeners by a combination of characters: blackish green dorsum with five continuous yellow longitudinal stripes; six sensillae on dorsal annulus a2 of segments VIII-XXV; greyish green ventrum with irregular bilateral dark brown spots; dorsum and abdomen separated by a pair of pale yellow stripes; front half atrium wrapped by white prostate; apparent albumen gland; epididymis massive in relation to ejaculatory bulb. The phylogenetic tree based upon COI implies a sister relationship to <i>H.nipponia</i> Whitman, 1886. A key to the known species is provided.