American Society of Hirudotherapy

Morphological data and DNA barcoding reveal the presence of the alien freshwater leech Helobdella octatestisaca (Hirudinida: Glossiphoniformes) in North Africa (Tunisia)

Species identification study published in Molecular Biology Reports (2024)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsBen Ahmed R et al. · Molecular Biology Reports, 2024

Abstract

BACKGROUND: We hereby report the first occurrence of Helobdella octatestisaca in North Africa, specifically in Tunisia, as a likely introduced species from the Neotropical Region. Historically, leeches bearing a prominent chitinous scute on their dorsal surface were commonly diagnosed as H. stagnalis. Most probably, H. octatestisaca had previously been misidentified as H. stagnalis in Tunisia. METHODS AND RESULTS: The identification was primarily based on morphological evidence, supplemented by genetic data obtained from COI DNA barcoding. The morphology of the examined specimens was consistent with the original species description, notably characterized by the presence of four pairs of testisacs. To support our findings, we conducted a phylogenetic analysis using the Maximum Likelihood method based on COI alignment constructed with the newly obtained sequence from Tunisian specimens and complete or nearly complete 'Folmer fragment' sequences of congeners sourced from the GenBank database. CONCLUSIONS: This study highlights the first identification of H. octatestisaca in North Africa and suggests that previous records of H. stagnalis in Tunisia likely misidentified this species.

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

Publication typeJournal Article
Indexed MeSH termsAnimalsPhylogenyLeechesDNA Barcoding, TaxonomicTunisiaFresh WaterIntroduced SpeciesElectron Transport Complex IV

Summary

First report of Helobdella octatestisaca (Neotropical origin) in North Africa, previously misidentified as H. stagnalis; identification by morphology (four pairs of testisacs) and COI DNA barcoding.

Why This Matters for Hirudotherapy

This study reports the first occurrence of the freshwater leech Helobdella octatestisaca in North Africa (Tunisia), likely an introduced species from the Neotropical Region, based on morphological evidence—including four pairs of testisacs consistent with the original species description—and COI DNA barcoding with Maximum Likelihood phylogenetic analysis. The authors suggest that previous Tunisian records of H. stagnalis likely represent misidentifications of H. octatestisaca. This is a taxonomic and biogeographic contribution documenting an alien freshwater leech species. The study has no relevance to hirudotherapy, the leech secretome, or therapeutic applications; H. octatestisaca is a non-medical freshwater leech, and the work addresses species distribution and identification rather than any medicinal property.

Citation

Morphological data and DNA barcoding reveal the presence of the alien freshwater leech Helobdella octatestisaca (Hirudinida: Glossiphoniformes) in North Africa (Tunisia).

Ben Ahmed R et al. · Molecular Biology Reports, 2024

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

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