# ERGA-BGE reference genome of Hirudo verbana, a once neglected freshwater haematophagous European medicinal leech

## TL;DR

This paper presents a high-quality reference genome for the southern medicinal leech, which could help study its biodiversity and gut microbiome.

## Contribution

The paper provides a chromosome-level reference genome for Hirudo verbana using a phased assembly approach.

## Key findings

- The genome was assembled into 14 chromosomal pseudomolecules with a total size of 0.18 Gb.
- The assembly includes a primary haplotype designated for annotation and further analyses.
- The genome has a contig N50 of 1.3 Mb and a scaffold N50 of 13.4 Mb.

## Abstract

Hirudo verbana Carena, 1820, commonly known as the southern medicinal leech, is one of several European medicinal leeches, whose full diversity has just recently started to be uncovered. Historically, it has been widely used as a medicinal leech and for centuries it was treated erroneously under the specific name of
Hirudo medicinalis L. 1758. Recent molecular and taxonomic analyses have revealed subspecific diversity within the morphospecies
H. verbana.
Hirudo verbana is a blood-feeding species sucking blood from amphibians, fish, and mammals. It occupies freshwater habitats, typically shallow ponds and lakes. Studies show that this leech species has a "naturally limited microbiome", suggesting it may serve as a powerful model system for the study of gut microbiota. We expect this chromosome-level assembly of
H. verbana to serve as a high-quality genomic resource for this most famous leech genus and to serve as a foundation to the study of the diversification and biodiversity of European medicinal leeches, as well as their gut-associated symbionts. The genome of
H. verbana was assembled into two haplotypes through a phased assembly approach; however, only the primary haplotype was designated as the reference genome for annotation and downstream analyses. The entirety of the primary haplotype was assembled into 14 contiguous chromosomal pseudomolecules, including the mitogenome. This chromosome-level assembly encompasses 0.18 Gb, composed of 277 contigs and 27 scaffolds, with contig and scaffold N50 values of 1.3 Mb and 13.4 Mb, respectively.