Element and carotenoid contents in the oyster Crassostrea gigas (Thunberg, 1793) with different shell pigmentation intensities

Contents of purple pigments in weakly and strongly pigmented shells of the Pacific oyster reared on a shellfish farm (Sevastopol, Crimea) were measured, and it was established that in soft tissues of oysters with strong shell pigmentation, the carotenoid content is significantly higher than in the weakly pigmented ones. The contents of the purple pigment in shells and carotenoids in soft tissues of two color morphs are described by a single linear relationship, and mechanisms of the pigment accumulation in shells and soft tissues appear to be coupled. It was shown that the concentrations of elements with small atomic numbers (Li-Ag) are generally higher in soft tissues of oysters with weakly colored shells, while the concentrations of heavier elements (Cd-U) tend to be higher in soft tissues of individuals with the intense shell pigmentation. The findings open the way toward making use of shell pigmentation as an indicator of the contents of biologically active materials in soft tissues of the Pacific oyster and breeding of oysters with strong shell pigmentation as more carotenoid-enriched and commercially valuable seafood.