Arsenic is a toxic metalloid that is widely distributed in the environment due to its persistence and accumulative properties. The occurrence, distribution, and biological effects of arsenic in aquatic environments have been extensively studied. Acute and chronic toxicities to arsenic are associated with fatal effects at the individual and molecular levels. The toxicity of arsenic in aquatic organisms depends on its speciation and concentration. In aquatic environments, inorganic arsenic is the dominant form. While trivalent arsenicals have greater toxicity compared with pentavalent arsenicals, inorganic arsenic can assume a variety of forms through biotransformation in aquatic organisms. Biotransformation mechanisms and speciation of arsenic have been studied, but few reports have addressed the relationships among speciation, toxicity, and bioavailability in biological systems. This paper reviews the modes of action of arsenic along with its toxic effects and distribution in an attempt to improve our understanding of the mechanisms of arsenic toxicity in aquatic organisms.

砷是一种有毒的准金属，由于其持久性和蓄积性，在环境中广泛分布。砷在水生环境中的发生、分布和生物学效应已得到广泛研究。砷的急性和慢性毒性与个体和分子水平的致命影响有关。砷在水生生物中的毒性取决于其形态和浓度。在水生环境中，无机砷是主要形式。虽然三价砷与五价砷相比具有更大的毒性，但无机砷可以通过水生生物的生物转化呈现多种形式。已经研究了砷的生物转化机制和物种形成，但很少有报告涉及物种形成、毒性、和生物系统中的生物利用度。本文回顾了砷的作用方式及其毒性作用和分布，以期提高我们对水生生物中砷毒性机制的理解。