A metabolomic investigation on arsenic-induced toxicological effects in the clam Ruditapes philippinarum under different salinities.

Arsenic is an important contaminant in the Bohai marine ecosystem due to the anthropogenic activities. In this work, we investigated the toxicological effects of arsenic in Ruditapes philippinarum under different seawater salinities using NMR-based metabolomics. Under normal salinity (31.1 ppt), arsenic decreased the levels of amino acids (glutamate, β-alanine, etc.), and increased the levels of betaine and fumarate. The metabolic biomarkers including decreased threonine, histidine, ATP and fumarate were found in the muscles of arsenic-treated clams under medium salinity (23.3 ppt). However, only elevated ATP and depleted succinate were detected in the arsenic-exposed clam samples under low salinity (15.6 ppt). These differential metabolic biomarkers indicated that arsenic could induce osmotic stress and disturbance in energy metabolism in clam under normal and medium salinities. However, arsenic caused only disturbance in energy metabolism in clam under low salinity. Overall, our results demonstrated that seawater salinity could influence the toxicological effects of arsenic.