State Key Laboratory of Oceanography in Tropics, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China.
Aquat Toxicol. 2011 Oct;105(3-4):582-8. doi: 10.1016/j.aquatox.2011.08.009. Epub 2011 Aug 27.
Arsenic (As) is a ubiquitous toxic metalloid that is causing widespread public concern. Recent measurements have indicated that some marine fish in China might be seriously contaminated with As. Yet the biokinetics and bioaccumulation pathway of As in fish remain little understood. In this study, we employed a radiotracer technique to quantify the dissolved uptake, dietary assimilation and subsequent efflux of As(V) in a marine predatory fish, Terapon jarbua. The dissolved uptake of As showed a linear pattern over a range of dissolved concentrations from 0.5 to 50 μg L(-1), with a corresponding uptake rate constant of 0.0015 L g(-1)d(-1). The assimilation efficiencies (AEs) of dietary As were only 3.1-7.4% for fish fed with copepods, clams, prey fish, or artificial diets, and were much lower than the As that entered the trophically available metal fraction in the prey. The dietary AEs were independent of the As(V) concentrations in the artificial diets. The efflux rate constant of As in fish following the dietary exposure was 0.03 d(-1). Modeling calculations showed that dietary uptake could be the primary route for As bioaccumulation in fish, and the corresponding contributions of waterborne and dietary uptakes were related to the bioconcentration factor (BCF) of the prey and the ingestion rate of fish. This study demonstrates that As(V) has a low bioavailability to T. jarbua.
砷（As）是一种普遍存在的有毒类金属，引起了广泛的公众关注。最近的测量结果表明，中国的一些海洋鱼类可能受到严重的砷污染。然而，鱼类中砷的生物动力学和生物积累途径仍知之甚少。在这项研究中，我们采用示踪技术来量化海洋掠食性鱼类褐菖鮋（Terapon jarbua）对砷（V）的溶解吸收、饮食同化和随后的排出。溶解吸收的砷在 0.5 到 50μg/L 的溶解浓度范围内呈现线性模式，对应的吸收速率常数为 0.0015 L g(-1)d(-1)。褐菖鮋从桡足类、双壳贝类、猎物鱼或人工饲料中摄入的砷的同化效率（AE）仅为 3.1-7.4%，远低于进入猎物中可利用金属部分的砷。饮食中 AE 与人工饲料中的砷（V）浓度无关。在进行饮食暴露后，鱼体内砷的排出速率常数为 0.03 d(-1)。模型计算表明，饮食摄入可能是鱼类砷生物积累的主要途径，而水相和饮食摄入的相应贡献与猎物的生物浓缩系数（BCF）和鱼类的摄食率有关。本研究表明，As(V)对褐菖鮋的生物利用率较低。
