Analysis on Physiological Metabolism in Reciprocal Cross Families of High Glycogen Content Line of Pacific Oyster (Crassostrea gigas)

Abstract:

Pacific oyster (Crassostrea gigas) is an euryhaline and eurythermal shellfish with the advantages of rapid growth and hardiness. Its breeding scale and production is the largest in the aquaculture, which has contributed to the economic growth and the improvement of the people's living standard in China. The annual output of aquaculture in China is 4.57 million tons in 2015, and the market demand for high quality oysters is ascending. Therefore, it is of great significance to improve nutritional quality and create new strain of oyster. In order to discover different physiological metabolisms between selfing lines and reciprocal crosses of C. gigas with various glycogen content, the filtration rate, oxygen consumption rate and ammonia excretion rate were studied under certain temperature (20℃) and salinity (32). In terms of the filtering rate, the highest one and the lowest one were selfing group AA and selfing group BB, respectively, which were significantly different (P<0.05). There was no significant difference between reciprocal group AB and reciprocal group BA. The heterosis value of the reciprocal cross was 8.44%. In the oxygen consumption rate, the highest one and lowest one were selfing group BB and reciprocal group AB, respectively. There was significant difference between AA and BB (P<0.05). The heterosis value of the reciprocal cross was –43.87%. The oxygen consumption rate was negatively correlated with the glycogen content with the correlation coefficient –0.884 that was significantly different (P<0.01). There was no significant difference for the ammonia excretion rate with 0.04 mg NH3-N/(g·h) among all groups. In summary, the major differences among groups were water filtration rate and oxygen consumption rate. This study could provide important physiological metabolic germplasm reference for the breeding of high glycogen content line of C. gigas.