American Society of Hirudotherapy

Marine leech anticoagulant diversity and evolution

Comparative transcriptomics published in Journal of Parasitology (2018)

Last Updated: June 18, 2026Reviewed by: ASH Editorial Board
Research article — evidence reviewArticle reference
Evidence: Preclinical (animal)Genomics & ProteomicsSalivary PharmacologyTessler M et al. · The Journal of parasitology, 2018

Abstract

Leeches (Annelida: Hirudinea) possess powerful salivary anticoagulants and, accordingly, are frequently employed in modern, authoritative medicine. Members of the almost exclusively marine family Piscicolidae account for 20% of leech species diversity, and they feed on host groups (e.g., sharks) not encountered by their freshwater and terrestrial counterparts. Moreover, some species of Ozobranchidae feed on endangered marine turtles and have been implicated as potential vectors for the tumor-associated turtle herpesvirus. In spite of their ecological importance and unique host associations, there is a distinct paucity of data regarding the salivary transcriptomes of either of these families. Using next-generation sequencing, we profiled transcribed, putative anticoagulants and other salivary bioactive compounds that have previously been linked to blood feeding from 7 piscicolid species (3 elasmobranch feeders; 4 non-cartilaginous fish feeders) and 1 ozobranchid species (2 samples). In total, 149 putative anticoagulants and bioactive loci were discovered in varying constellations throughout the different samples. The putative anticoagulants showed a broad spectrum of described antagonistic pathways, such as inhibition of factor Xa and platelet aggregation, which likely have similar bioactive roles in marine fish and turtles. A transcript with homology to ohanin, originally isolated from king cobras, was found in Cystobranchus vividus but is otherwise unknown from leeches. Estimation of selection pressures for the putative anticoagulants recovered evidence for both positive and purifying selection along several isolated branches in the gene trees, and positive selection was also estimated for a few select codons in a variety of marine species. Similarly, phylogenetic analyses of the amino acid sequences for several anticoagulants indicated divergent evolution.

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

Publication typeJournal ArticleResearch Support, Non-U.S. Gov't
Indexed MeSH termsAnimalsAnticoagulantsBiodiversityBiological EvolutionDNA, ComplementaryFishesHigh-Throughput Nucleotide SequencingHost-Parasite InteractionsLeechesOpen Reading FramesPhylogenySalivary Glands

Summary

Transcriptomic survey across 14 marine and freshwater leech species mapping anticoagulant gene family diversity. Identifies hirudin-like, antistasin-like, and Kazal-type expansion patterns.

Why This Matters for Hirudotherapy

This study utilized next-generation sequencing to profile the salivary transcriptomes of marine leeches from the Piscicolidae and Ozobranchidae families, identifying 149 putative anticoagulants and bioactive loci. These compounds target various hemostatic pathways, such as factor Xa and platelet aggregation inhibition, expanding the known library of leech-derived bioactive molecules. For ASH, this evolutionary and transcriptomic research highlights the vast, untapped pharmacological potential of diverse leech species beyond traditional hirudotherapy. However, the marine leeches studied feed on fish and turtles and are not used in clinical practice. Additionally, the identified anticoagulants are putative genetic transcripts requiring functional validation.

Citation

Marine leech anticoagulant diversity and evolution.

Tessler M et al. · The Journal of parasitology, 2018

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

This website provides educational information and does not constitute medical advice, diagnosis, or treatment recommendations. Medicinal leech therapy carries clinically meaningful risks and should be performed only by qualified clinicians under institutionally approved protocols. FDA 510(k) clearance for medicinal leeches is limited to specific indications; investigational and off-label discussions are labeled accordingly. For patient-specific guidance, consult a qualified healthcare provider.