Features of carotenoid accumulation in the bivalve Abra segmentum in the Black Sea

The bivalve mollusk Abra segmentum is widespread on the Crimean coast in sandy-silty soils. Its adaptive capabilities to changes in salinity, temperature and hypoxia are interesting from the point of view of the participation of carotenoids in them. The aim of the work was to study the carotenoids of this mollusk in the coastal zone at a depth of 0-0.2 m. In the period from February to April, the level of total carotenoids in the mollusk tissues fluctuated from 1.7 ± 0.2 mg / 100 g dry matter to 0.4 ± 0.1 mg / 100 g dry matter. The study of the carotenoid composition of A. segmentum mollusks taken in coastal zones showed the presence of 11 carotenoids, including isomers and esters of 3 carotenoids. Among the dominant carotenoids are: β-carotene (15.2%), diadinoxanthin (7.3%), fucoxanthin (5.8%), trans-halocynthiaxanthin (9.3%), cis-halocynthiaxanthin (7.6%), trans-pectenol A (13.6%), cis-pectenol A (7.9%). A. segmentum accumulated both plant carotenoids and subjected some to metabolic transformation: fucoxanthin→ fucoxanthinol→ halocynthiaxanthin (cis- trans); diatoxanthin→ pectenol A (cis- trans-). The possible role of A. segmentum carotenoids in death of fish due to hypoxia discussed.