American Society of Hirudotherapy

Description of two new species of freshwater leeches of the genus Theromyzon (Hirudinea, Glossiphoniidae) from Mexico

Taxonomy study published in ZooKeys (2025)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Research reportGenomics & ProteomicsTorres-Carrera G et al. · ZooKeys, 2025

Abstract

Freshwater leeches of the genus Helobdella Blanchard, 1896 (Annelida: Clitellata) are widely distributed in the New World, with most of the species occurring in the neotropics and a single species native to Europe. Species of the genus are characterized by the presence of an eversible proboscis, dorsoventrally flattened body, presence of a single pair of eyespots, and a preference for feeding on the hemolymph of aquatic invertebrates. In this study, two new species of Helobdella are described based on specimens collected in Mexico, Helobdella papilloprocta sp. nov. and Helobdella gulloae sp. nov. These specimens were preliminarily identified as H. socimulcensis (Caballero, 1931), but detailed morphological and molecular analyses confirmed their status as separate species. In addition, a neotype for Helobdella socimulcensis is designated, and a redescription of the species is provided based on specimens from the type locality: Xochimilco, Mexico City, Mexico. Finally, H. austinensis in Nuevo León and H. europaea in Morelos, Mexico are reported for the first time, representing new records for the country. In total, ten species of Helobdella are known from Mexico.

Abstract sourced from PubMed (NCBI) for the cited record. See the original publication for the authoritative version.

Publication typeJournal Article

Summary

Describes two new Theromyzon species from Mexico via multilocus molecular and morphological data — adds to known Glossiphoniidae diversity.

Why This Matters for Hirudotherapy

This article details the taxonomic description of two new species of freshwater leeches from the genus Helobdella found in Mexico, confirmed through morphological and molecular analyses. The study also designates a neotype for Helobdella socimulcensis and reports new geographical records for the country. While it contributes to the broader documentation of leech biodiversity, the research possesses minimal direct relevance to clinical hirudotherapy. The species investigated are freshwater leeches that feed on the hemolymph of aquatic invertebrates rather than medical leeches used in human therapy. Thus, its utility for ASH is strictly confined to the field of leech taxonomy and ecology.

Citation

Description of two new species of freshwater leeches of the genus Theromyzon (Hirudinea, Glossiphoniidae) from Mexico.

Torres-Carrera G et al. · ZooKeys, 2025

Added to ASH library: May 27, 2026 · Site last updated: June 18, 2026

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