Aquaculture Reports (Aug 2024)
Genetic diversity and population structure of wild and artificially selected populations of the ridgetail white prawn (Exopalaemon carinicauda) using consolidated mitochondrial cytochrome b and microsatellite markers
Abstract
The ridgetail white prawn (Exopalaemon carinicauda) belongs to the family Palaemonidae and genus Exopalaemon. Owing to its significant economic value and excellent nutritional properties, it is an important species for the development of saltwater aquaculture models in China. In this study, 160 individuals were collected from four wild populations and one artificially selected population using consolidated mitochondrial cytochrome b (mt-cyt b), and microsatellite molecular markers. The results showed that the hatcheries had lower genetic diversity than the wild samples, both at the levels of mt-cyt b (haplotype diversity: 0.123 VS 0.572; nucleotide diversity: 0.0003 VS 0.0014) and microsatellite (expected heterozygosity: 0.672 VS 0.752). Among the four wild populations, the Ningbo population sampled from the East China Sea showed higher genetic diversity in both mt-cyt b and microsatellites. A pairwise comparison of genetic differentiation coefficients revealed that the artificially selected population had not genetically diverged from the Cangzhou and Rizhao populations. However, the Ningbo population exhibited moderate to high genetic differentiation (compared to other populations), whereas the Zhanjiang population showed a high level of genetic differentiation, indicating a distinct geographical distribution pattern. Structural analysis revealed the presence of three lineage clusters in all current populations, and the artificially selected population predominantly consisted of lineage 3, accounting for 71.68 % of the population. Currently, the effective population size of hatcheries was <50, rendering them susceptible to the genetic threat of inbreeding depression. These findings provide a scientific basis for the conservation of wild germplasm resources of E. carinicauda and inform future breeding and management strategies for improved varieties.
