Abstract:On June 25, 2023, two leech specimens were collected from the north bank of Fengquan River Park in Aksu Prefecture, Xinjiang Uygur Autonomous Region, China (41°08′56″ N, 80°16′52″ E, 1 100 m a.s.l.) (Figs. 1 and 2). The COI gene sequences of the specimens were obtained through extraction and amplification, and then compared with other species sequences in GenBank, followed by manual correction. We constructed a phylogenetic tree based on mitochondrial COI gene sequence (646 bp). The results showed that the collected specimens clustered with Whitmania pigra from other regions (Fig. 3), with a genetic distance ranging from 0.5% to 6.2% (Appendix 2), which was significantly lower than the genetic distance (11.1% ~ 26.5%) between W. pigra and other closely related species within the same family, including both congeneric and non-congeneric taxa (Appendix 3). Combined with morphological comparison, the collected specimens exhibit body size, coloration, patterns, longitudinal stripes, tail sucker size, and reproductive system morphology and structure that are consistent with those of W. pigra. Thus, the collected specimens were identified as W. pigra. Meanwhile, W. pigra is widely distributed across most regions of China and is currently known to occur only in Japan outside China. Therefore, based on the currently known distribution range of W. pigra, the collected sample represents a new distribution record for the Xinjiang Uygur Autonomous Region.