Abstract:Hybrid abalone () have been cultured in southern China for many years. Two experiments were performed (high temperature stress and culture in a southern sea area) to study whether a southern population (hybrid population) of Pacific abalone has different high temperature tolerance and is more adapted to that environment than a northern population (inbred population). After a 30℃ stress or in the high temperature stress experiment, relative expression of heat shock protein (HSP) 70 in the southern population at 0h of the recovery phase was significantly higher in the foot, mantle, gill, and hepatopancreas than those in the northern population (<0.05). At the same time, relative expression of HSP90 in the southern population was significantly higher in the mantle and hepatopancreas than that in the northern population. The relative expression levels of HSP70 and HSP90 in the southern population after the 33℃ stressor were significantly higher in the foot, mantle, and hepatopancreas at 0 h in the recovery phase than those in the northern population (<0.05). In another experiment, the most rapid growth period in the northern population occurred from December to February;abalone in the northern population grew faster than those in the southern population and water temperature was no higher than 17.11℃ at this time. Water temperature eventually exceeded 20℃ in March, when the northern population grew slower than the southern population and mortality increased. Less than 30 abalone in the northern population remained in July. Taken together, we conclude that because hybrid abalone have been cultured for many generations in southern China, they became better adapted to higher water temperature. The relative expression levels of HSP70 in the two populations were positively correlated with heat resistance after the 30℃ stressor. These data could be useful for assisted selection in an abalone high temperature resistance breeding program.