Seasonal Dynamics of Tissue Lipids in Bivalve Mollusk Cerastoderma glaucum of Supralittoral Zone

Abstract

Cerastoderma glaucum is a bivalve mollusk that inhabits the supralittoral zone of the Black Sea. It is a potential object of commercial aquaculture, which makes its lipid profile and adaptation mechanisms a prospective research topic. The authors analyzed the annual patterns in total lipids, phospholipids, polyglycerides, diglycerides, sterols, free fatty acids, and triacylglycerides to obtain the fatty acid profile of C. glaucum, harvested from the supralittoral zone of the upper Kazachya Bay, Sevastopol, Russia. The mollusks were collected in the winter, spring, and autumn of 2021–2022. This research featured their gills, foot, and hepatopancreas. An integrated methodological approach was used to d etermine total lipids, classify them, and study fatty acids. The total lipid level was 2.4–15.1 g/100 g raw weight. During the year, the dynamics of total lipids in the tissues of foot and gills varied from the highest values in the spring (9.6 ± 1.6 and 4.9 ± 1.9 g/100 g raw weight, respectively) to the lowest in the autumn (5.5 ± 0.5 and 2.5 ± 0.4 g/100 g raw weight, respectively). In the hepatopancreas, it peaked the winter and dropped in the autumn (19.4 ± 1.9 and 2.9 ± 0.4 g/100 g raw weight, respectively). In the winter, all tissue samples demonstrated a significant decrease in triacylglycerides. The composition of fatty acids and total lipids in all tissues included 23 types, i.e., nine saturated (35–40%), eight monounsaturated (15–34%), and six polyunsaturated (5.8–29%) from the families of omega-3, 5, 6, 7, 9, 11, and 13. Palmitic and oleic acids were among the dominant fatty acids. Seasonal dynamics of lipids in the samples of foot, gills, and hepatopancreas of C. glaucum revealed some general patterns. In the spring, total lipids peaked while structural and storage lipids had a uniform distribution. In the autumn and winter, total lipids went down whereas structural lipids increased. The fatty acid profile of C. glaucum from the supralittoral zone of the Black Sea differed from those of the same species from o ther regions.