Saturday, April 16, 2022

[Invertebrate • 2022] Hirudo tianjinensis • A New Species of Medicinal Leech in the Genus Hirudo Linnaeus, 1758 (Hirudiniformes, Hirudinidae) from Tianjin City, China


Hirudo tianjinensis Liu,

in Wang, Meng, Jin, ... et Liu, 2022. 

Abstract
Medicinal leeches in the genus Hirudo have been utilized for therapeutic procedures for thousands of years. To date, six known species of Hirudo are widely distributed in different regions of the Eurasian continent. In this study, a new medicinal leech species Hirudo tianjinensis Liu, sp. nov. 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 H. nipponia Whitman, 1886. A key to the known species is provided.

Keywords: Blood-feeding leech, COI, molecular phylogeny, new species, taxonomy


Map of geographic collecting locations for three species of Chinese leeches. Hirudo tianjinensis and H. nipponia were collected in adjacent areas of Tianjin City, and Haemadipsa yanyuanensis was collected in Yunnan Province.

External morphology of Hirudo tianjinensis holotype
A dorsal and B ventral view of whole body C dorsal and D ventral view of somites X–XIV E dorsal and F ventral view of somites I–VIII G dorsal and H ventral view of somites XXIV–XXVII and caudal sucker.
Abbreviations: an, anus; e, eye; fg, female gomopore; mg, male gomopore; np, nephridiopores.
 Scale bars: 5 mm (A, B), 2.5 mm (C–H).

Taxonomy: 
Family Hirudinidae Whitman, 1886

Genus Hirudo Linnaeus, 1758

 Hirudo tianjinensis Liu, sp. nov.

 Diagnosis: Hirudo tianjinensis can be distinguished from its congeners by the following combination of characters: blackish green dorsum with five continuous yellow longitudinal stripes; six sensillae on dorsal annulus a2 of segments VIII–XXV making dorsal golden midline notched, and two lateral blackish green dorsal line rosary; greyish green ventrum with irregular dark brown spots bilaterally; dorsum and abdomen separated by a pair of pale yellow stripes; front half of atrium wrapped by white prostate; apparent albumen gland; epididymis massive in relation to ejaculatory bulb.

Etymology: The specific name tianjinensis is derived from Tianjin City, a municipality directly under the central government in China, where type specimens were collected.

Distribution: Hirudo tianjinensis was collected from Caobai River, Haogezhuang Town, Baodi District, Tianjin City, China, which flows into Bohai Sea. Water was moderately polluted. Aquatic plants and irregular pumice stones were abundant along the riverbed. This species normally hid under pumice stones. Whenever people and animals pass by, it quickly adsorbs on their ankles for sucking blood.


Hao Wang, Fan-Ming Meng, Si-Jie Jin, Jiang-Wei Gao, Xiang-Rong Tong and Zi-Chao Liu. 2022. A New Species of Medicinal Leech in the Genus Hirudo Linnaeus, 1758 (Hirudiniformes, Hirudinidae) from Tianjin City, China.  ZooKeys. 1095: 83-96. DOI: 10.3897/zookeys.1095.74071