American Society of Hirudotherapy

Morphological data and DNA barcoding reveal the presence of the alien freshwater leech Helobdella octatestisaca in North Africa

Invasion biology 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 record of the alien freshwater leech Helobdella octatestisaca in North Africa, confirmed by morphology and DNA barcoding — flags potential invasion-biology risks.

Why This Matters for Hirudotherapy

This study used morphological examination and COI DNA barcoding to report the first occurrence of the freshwater leech Helobdella octatestisaca in North Africa (Tunisia), likely a Neotropical introduction previously misidentified as H. stagnalis. For ASH's domain, the article is of only indirect relevance: it concerns taxonomy and introduced-species distribution of a non-medicinal, freshwater glossiphoniid leech rather than Hirudo or hirudotherapy. The study has no therapeutic, clinical, or salivary-secretome findings, and no medicinal-leech species are involved. Its value is limited to biodiversity and biogeographic documentation within the broader leech literature.

Citation

Morphological data and DNA barcoding reveal the presence of the alien freshwater leech Helobdella octatestisaca in North Africa.

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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