Effect of salinity on the bioaccumulation and depuration of cadmium in the pacific cupped oyster, Crassostrea gigas

Publication date: September 2018Source: Environmental Toxicology and Pharmacology, Volume 62Author(s): Ming Sun, Guangbin Liu, Hong Lin, Tianwen Zhang, Wen GuoAbstractAs a euryhaline species, the oyster Crassostrea gigas can adapt rapid and dramatic salinity fluctuations, and show physiological mechanisms of adaption to tolerant salinity changes. They are continuously exposed to Cd because they are filter feeders and their mobility is poor. In order to understand the influence of salinity on the molecular responses of C. gigas exposed to Cd, oysters were acclimatized to different salinities (13, 20, 27, and 34) for 14 days and then exposed to 10 μg/L Cd for 28 d, followed by a depuration period of 35 d. Control groups were kept at the same salinities without Cd. Oysters were sampled for chemical analysis by inductively coupled plasma mass spectrometry (ICP-MS) and for mRNA quantification by qPCR. The rank order of the mean concentrations of Cd in oyster tissues was digestive gland > mantle > adductor muscle. Use of a two-compartment model showed that in the three tissues, Cd uptake rates (k1) in digestive gland (13.525–35.430 d−1) also increased as salinity decreased. However, no difference was observed in Cd uptake rates of C.gigas in the three higher salinities in mantle (11.703–17.250 d−1). Cd depuration rates (k2) (0.0139 - 0.0127 d-1 in mantle and 0.0111-0.0134 d−1 in digestive gland) followed a reverse trend. There was not a relationship between k2 ...
Source: Environmental Toxicology and Pharmacology - Category: Environmental Health Source Type: research