Although it has been shown that trophic transfer of trace elements in oysters can be influenced by the diet, most of the studies investigating the ability of oysters to bioaccumulate trace elements from their diet are based on experiments using phytoplankton alone. Wild oysters feed also on large bacteria, ciliates or detritic organic matter. The present study aimed at examining the influence of quality of food on the assimilation efficiency (AE) of trace elements in the Pacific cupped oyster Crassostrea gigas. Oysters were exposed via their food to the radiotracers of essential (⁵⁷Co, ⁵⁴Mn and ⁶⁵Zn) and non-essential (^110mAg, ¹⁰⁹Cd and ²⁴¹Am) trace elements under different diets (protozoan ciliates Uronema marinum and diatoms Thalassiosira pseudonana). Significant differences were found only for Ag and ²⁴¹Am, with lower AEs measured in oysters fed with ciliates than in individuals fed with diatoms (Ag: 54 ± 3% vs. 67 ± 4% for Ag and ²⁴¹Am: 62 ± 4% vs. 76 ± 4%). Interestingly, no significant difference was found among estimated depuration rates (k_el) for all trace elements ingested with the two diets tested. These findings indicate that the differences observed are driven by the digestion process, presumably due to difference of bioavailability of trace elements dependent on the quality of the food ingested.

尽管已经证明牡蛎中微量元素的营养转移可能受到饮食的影响，但是大多数研究牡蛎从饮食中生物富集微量元素的能力的研究都是基于仅使用浮游植物的实验。野生牡蛎也以大型细菌，纤毛或有害有机物为食。本研究旨在检验食品质量对太平洋杯牡蛎Crassostrea gigas中微量元素同化效率（AE）的影响。牡蛎通过食物暴露于必需（⁵⁷ Co，⁵⁴ Mn和⁶⁵ Zn）和非必需（^110m Ag，¹⁰⁹ Cd和²⁴¹）的放射性示踪剂中Am）在不同饮食下的痕量元素（原生动物纤毛虫Uronema marinum和硅藻Thalassiosira pseudonana）。仅在Ag和²⁴¹ Am上发现有显着差异，在饲喂纤毛虫的牡蛎中测得的AEs低于使用硅藻喂养的个体（Ag：54±3％，Ag和²⁴¹ Am：62±4％vs 76±4％）。有趣的是，在两种测试饮食中摄入的所有微量元素的估计净化率（k _el）之间没有发现显着差异。这些发现表明，观察到的差异是由消化过程驱动的，大概是由于微量元素的生物利用度的差异取决于所摄入食物的质量。