| Summary: | Cadmium (Cd) is commonly detected in aquatic environment and can accumulate in maricultural organisms. Modification of the food may change the bio-kinetics of trace metals in organisms. The aim of this study was to understand the effects of food type on the uptake and elimination of Cd in different tissues of oyster Crassostrea gigas. Oyster groups feeding with different food types were exposed to 10 μg/L Cd for 28 days, and then followed by a depuration of 35 days. One group was added natural seawater rich in algae, the other three groups were fed once daily with Dicrateria inornata, Nitzschia closterium f.minutissima and mixed alga (Dicrateria inornata: Nitzschia closterium f.minutissima=1:1), respectively. Oysters were sampled for chemical analysis by inductively coupled plasma mass spectrometry (ICP-MS). The mean concentrations of Cd among different oyster tissue were followed the order as: digestive gland > mantle > adductor muscle. A two-compartment model was used to estimate Cd uptake rates (k1), depuration rates (k2), bioconcentration factor (BCF), and half-lives (t1/2) in the three tissues, showing k1 was considerately higher than k2, therefore, the organism have high ability to accumulate Cd. The k1 in the digestive gland was the highest, followed by mantle and adductor muscle, while the k2 in the mantle was the lowest. In the present study, the group fed with mixed algae showed the fastest depuration rate and the shortest t1/2 in the important edible part of the oysters (digestive gland), which helps to improve food safety.
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