Abstract
During July-October 2024, forty sanguivorous leeches were collected from five freshwater springs in the Taqtaq district, Erbil Governorate, Iraq.
The specimens were fixed, preserved, and identified to the species level using both morphological and molecular approaches. Morphological identification included detailed examination and photographic documentation of external features such as body coloration, sucker shape, eye arrangement, clitellum, and gonopore position, as well as internal structures including the pharynx, salivary glands, crop, intestine, and reproductive system. All specimens displayed consistent diagnostic characteristics corresponding to the genus Limnatis.
Molecular confirmation was performed using PCR amplification and sequencing of the nuclear 18S rDNA region and the mitochondrial cytochrome c oxidase subunit I (COI) gene. Comparison of the resulting sequences with GenBank data verified the identity of all examined specimens as Limnatis paluda (L. paluda), showing 100% similarity with reference sequences. Representative COI sequences were deposited in GenBank under accession numbers PV056019.1, PV018631.1, PQ868999.1, and PQ553448.1. Phylogenetic relationships were reconstructed using the Maximum Likelihood (ML) approach, further supporting the placement of the samples within the L. paluda clade, demonstrating the reliability of molecular tools as a complement to classical morphological identification.
The bacterial community of the leech’s intestinal tract was characterized using 16S rRNA gene sequencing supported by standard biochemical assays. Three species of Aeromonas were detected: A. hydrophila (99%; GenBank accession numbers PV803522, PV809903, PV809904, PV809905, PV809942, and PV809885), A. veronii (99%; PV806076), and
A. salmonicida (98%; PV806328, PV809945, and PV809947). This study documents, for the first time, the presence of these bacterial taxa associated with L. paluda in the Kurdistan Region, highlighting the potential role of this leech as a reservoir of opportunistic pathogens.
This study provides the first integrated characterization of the morphology, molecular identity, and intestinal microbiota of L. paluda from Erbil Governorate. The resulting dataset establishes a critical empirical foundation for future investigations into leech systematics, ecological interactions, and potential host pathogen interactions.
