Blue tilapia (BT) and Nile tilapia (NT) are two closely related species with distinct cold-resistance phenotype. BT happens to be one of the most cold-tolerant tilapia species and has stronger cold resistance than NT. The low degree of interspecies genetic differentiation, significant phenotypic discrepancy and rich genomic resources offer great opportunity to mine the candidate genes that are highly differentiated and responsible for the different cold-resistance ability. The project is aimed to disclose the the candidate genes that are highly differentiated and responsible for the different cold-resistance ability.