Construction of the Red Swamp Crayfish () Family Selection Population and Whole Genome Sequencing to Screen Candidate Genes Related to Growth.

is an important freshwater aquaculture species in China which has the characteristics of rich nutrition and delicious taste. However, the expansion of aquaculture scale, germplasm degradation, and other problems that have become increasingly prominent seriously restrict the sustainable development of the crayfish industry. Genetic improvement is an urgent need for the crayfish aquaculture industry, and selective breeding is an important way to improve the crayfish varieties. We established full-sibling family populations of the red swamp crayfish and performed whole-genome resequencing of the F3 family-selected red swamp crayfish population and wild red swamp crayfish populations from four regions of Hunan Province (Nanx, Mil, Caish, and Wangc). The results showed that there was a clear separation between the wild population and the family population, and the decline rate was slightly faster in the wild population than that of the family breeding population. There was local gene flow between family populations, as well as gene flow between Mil, Caish, and families. In addition, 52 SNP loci related to body weight traits were identified by genome-wide association analysis, and the candidate gene related to growth was screened out. We established a line selection population of red swamp crayfish and obtained more stable candidate lines. In addition, this study identified as a candidate gene related to body weight for the first time. The results provide a theoretical basis for exploring the growth mechanism of and carrying out in-depth genetic improvement.