Variation of lipids and fatty acids in noble scallop Chlamys nobilis under low temperature stress

Low temperature is an important stress factor for warm-water marine mollusks. It is well known that lipids play an important role in the resistance of low temperature stress in mollusks. The noble scallop Chlamys nobilis is an important economic warm-water bivalve. It has been cultured in the waters of southern China since the 1980s. However, C. nobilis often experiences regional mass mortality in winter. In the present study, the variation of lipids and fatty acids in C. nobilis were studied in differentiated temperatures (water temperature was gradually decreased from 27 °C to 15, 13 and 11 °C). The results demonstrated that lipid peroxidation increased at low temperatures, gills were damaged at 13 and 11 °C, and the condition index decreased only at 11 °C. Moreover, the level of triglycerides and total cholesterol in digestive glands increased significantly at 15 and 13 °C, and the triglycerides in adductor muscles also increased significantly at low temperatures. Furthermore, the level of ∑n-6 PUFA in digestive glands and adductor muscles increased significantly, the level of ∑n-3 PUFA and EPA + DHA in adductor muscles increased significantly, whereas the level of ∑n-3 PUFA and EPA + DHA in digestive glands decreased significantly at 13 and 11 °C. This is the first report on the variations of lipids and fatty acids in mollusks under chronic low temperature stress. The present results also showed that both lipids and PUFA played important roles in animal resistance to low temperature stress, which can provide guidance for improving low temperature tolerance of bivalves. •Low temperature induce gill damage and lipids peroxidation in noble scallop.•Triglycerides and cholesterol of digestive gland increased at low temperature.•Triglycerides and cholesterol decreased at near lethal low temperature (11 °C).•Low temperature stress increase the EPA + DHA in adductor muscle.•Low temperature stress decrease the EPA + DHA in digestive gland.