# Genome-wide detection of fine-scale population stratification and long-distance dispersal of the Chinese mitten crab (Eriocheir sinensis)

## TL;DR

This study uses genomic data to reveal population structure and dispersal patterns in Chinese mitten crabs across East Asia.

## Contribution

The study identifies fine-scale genetic differentiation and long-distance dispersal in Eriocheir sinensis using genome-wide SNP data.

## Key findings

- Genetic differentiation among regional populations is correlated with geography.
- Seocheon and Wenzhou populations share a unique genetic ancestry, possibly due to hybridization.
- Genetic outliers suggest long-distance dispersal along the Yellow Sea during the larval phase.

## Abstract

Understanding the population genetic structure of marine decapods is essential for their effective conservation and management, particularly for species like the Chinese mitten crab (Eriocheir sinensis), which exhibits a complex life cycle and high invasive potential. In this study, we applied a population genomics approach using SLAF-seq to generate genome-wide SNP data from 120 unrelated individuals collected across six locations in China and Korea. We found a fine-scale but discernible level of genetic differentiation by regional populations correlated with geography. Individuals from Seocheon (Korea) and Wenzhou (southeastern China) exclusively share a distinct genetic ancestry component that makes them divergent from the rest, which we speculate may have been introduced by hybridization with congeneric species. We detected genetic outliers (9 out of 120 individuals) that show ongoing long-distance dispersal along the coastline of the Yellow Sea, likely happening during the planktonic larval phase. Collectively, our findings provide a genomic basis for delineating management strategies, supporting informed stock enhancement, and guiding region-specific conservation efforts for E. sinensis across East Asia.