Phylogeography of the freshwater crab Potamon persicum (Decapoda: Potamidae): an ancestral ring species?

The Zagros Mountains, characterized by complex topography and three large drainage systems, harbor the endemic freshwater crab Potamon persicum in Iran. Our study delves into the evolutionary history of P. persicum, utilizing two mitochondrial and one nuclear marker. We collected 214 specimens from 24 localities, identifying 21 haplotypes grouped into two major evolutionary lineages. Substantial differentiation exists between drainage systems and lineages. Historical demographic analysis revealed a significant decrease in population size during the late-Holocene, accompanied by a recent population bottleneck. Species distribution modelling has revealed eastward shifts in suitable habitats between the last glacial maximum and the present day. Following the last glacial maximum, habitat fragmentation occurred, resulting in the establishment of small populations. These smaller populations are more vulnerable to climatic and geological events, thereby limiting gene flow and accelerating gen..., Sample Collection
A total of 214 specimens of P. persicum (Fig. 1) were collected from 24 localities, encompassing more than 280,000 km2, covering the entire distribution range of the species in Iran. To gain a more precise understanding of geographical structuring, the specimens were taken from three geographically distant drainage systems, Urmia, Khali Fars-Oman and Markazi basins (Fig. 2).
DNA Extraction and PCR Amplification
Total genomic DNA was extracted from the muscle tissue of walking legs using the Sambio DNA reagent kit. Three markers, mitochondrial Cytochrome Oxidase subunit 1 (CO1), mitochondrial 16S rRNA (16S), and nuclear Histone 3 (H3) were selected for their wide application in crustacean population diversity and structure studies (Klaus et al. 2010, 2014: Jesse et al. 2011; Keikhosravi et al. 2015; Phiri and Daniels 2016; Daniels and Klaus 2018; Parvizi et al. 2018, 2019; Gao et al. 2019; Stark et al. 2021). Final sample sizes differed for markers, we amplified CO1 for..., , # Supplementary Data

[https://doi.org/10.5061/dryad.m63xsj49d](https://doi.org/10.5061/dryad.m63xsj49d)

## Description of the data and file structure

All sequences in the FASTA format.
An Excel file containing details about sampling localities and NCBI Accession Numbers.

## Sharing/Access information

Links to other publicly accessible locations of the data:

* [https://www.ncbi.nlm.nih.gov/nuccore](https://www.ncbi.nlm.nih.gov/nuccore)

Data was derived from the following sources:

* All physical specimens are deposited in the Museum of the University of Tehran.