Abstract:Atrina pectinata is a large deepwater mollusk that is widely distributed in temperate and tropical ocean waters. The China costal line, from the Liaodong peninsula in the north to the Qiongzhou strait in the south, is a major habitat of Atrina pectinata. The provinces along the costal line included Liaoning, Shandong, Fujian and Guangdong, etc. This bivalve animal possesses high economic and medicinal values. The dried scallop of A. pectinata is large in size and has a tender texture and delicious taste. In recent years the overfishing has caused a rapid drop in the natural resource of Atrina pectinata and thus hindered the breeding in the aquaculture industry. The difficulty in the spawning inducement and the larval adhesion during culture has been the major issues in the large-scale production of A. pectinata seed. In the present study we explored different inductive methods and identified the optimal one to improve the fertilization rates and the embryonic development. Our study suggested that the combination of thermal stimulation (3℃ rise in the temperature) and sodium hypochlorite would neutralize the seawater and could be the optimal spawning-inducing method without noticeable impact on the fertilization rate and the embryonic development. To reduce the larval adhesion during the breeding, we adopted a lower breeding density and changed the incubation method. It was found that the larval adhesion could be effectively avoided at a lower larval density, and that at the density of 1 ind/ml the larval survival rate reached the maximum. Moreover, we also changed the cultural method for the A. pectinata larvae by equipping the cultivating pool with a surf pump. The surf pump generated a water flow inside the pool that prevented the larval adhesion and thus improved the larval survival rates. Our study provided a valuable tool for the large-scale production of the seed of A. pectinata.
