Environmental Cadmium Exposure Impacts Physiologic

Authors: Liqiang Zhao Yu Zhang Jian Liang Xian Xu Hua Wang Feng Yang Xiwu Yan

Publish Date: 2014/04/29

Volume: 159, Issue: 1-3, Pages: 241-253

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Abstract

The physiological responses of marine bivalves to chronic cadmium Cd exposure at sublethal concentrations have been well documented As of now few studies have examined the effect of Cd exposure and subsequent recovery period at environmentally realistic concentrations In this study environmentally Cd exposures were performed to assess the physiological responses of the Manila clam Ruditapes philippinarum The clams were exposed to waterborne Cd at two environmentally realistic concentrations 4 and 40 μg L−1 for 35 days and then allowed to recover for another 35 days The accumulation and elimination of Cd in R philippinarum were tissuespecific and dose and timedependent Cd accumulation increased sharply in the digestive gland and Cd elimination was rapid in the gill Major physiological responses including clearance rate absorption efficiency respiration rate excretion rate oxygen to nitrogen ratio and scope for growth were significantly affected by Cd exposure Yet the clams exposed to 4μg L−1 Cd were able to quickly recover their normal physiological processes and clearly exhibited catchup growth once they were transferred to clean seawater Hence R philippinarum can exhibit good physiological plasticity when confronted with moderately environmental Cd exposure All physiological responses measured exhibited a highly significant and generally predictable correlation with tissue Cd concentration which in turn reflected environmentally realistic exposure conditions Our results further confirm that the measurement of physiological responses is a sensitive method for assessing stress at environmentally realistic metal concentrationsThe authors would like to acknowledge the following people for technical assistance Dawei Zhang Wuting Lu and Yinhou Zhang This project was financially supported by the earmarked fund for Modern Agroindustry Technology Research System CARS–48 the Science and Technology Foundation of Education Department of Liaoning Province L2011117 and the Public Science Research Funds Projects of Liaoning Province 2012005002

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