The development of anuran larvae from hatchling through metamorphosis is a particularly sensitive life stage that often is studied to assess adverse effects of water pollution, such as metal contamination. As an integral part of the food chain, high metal exposure and accumulation in developing anuran larvae may not only affect their survival but also pose a threat to secondary consumers. The presented work examines metal accumulation in wood frog tadpoles (Lithobates sylvaticus) before and after reaching metamorphic climax at emergence of the forelimbs. Metal levels were determined in whole tadpoles pre- and post-metamorphic climax in tadpole tissue excluding the stomach and intestines, as well as in water, via inductively coupled plasma-mass spectrometry. Wood frog tadpoles concentrated metals in their gut coil, with a rapid decline coincident with metamorphic climax. Tadpoles raised in a diluted bitumen-contaminated environment had higher levels of vanadium, molybdenum and cadmium, but not at levels expected to negatively impact development. In conclusion, metal accumulation in wood frog tadpoles varies greatly depending on developmental stage surrounding metamorphic climax. Metabolic changes and intestinal remodelling must be considered when studying pollutants in developing anuran larvae.

中文翻译：

---

前变质木青蛙（Lithobates sylvaticus）Ta中的金属变化：对生态毒理学研究的启示。

从孵化到变态的无核幼虫的发育是一个特别敏感的生命阶段，经常对其进行研究以评估水污染（例如金属污染）的不利影响。作为食物链中不可或缺的一部分，发育中的金刚鹦鹉幼虫的大量金属暴露和积累不仅可能影响其生存，而且还会对二级消费者构成威胁。提出的工作研究了在前肢出现变质高潮前后木蛙t（Lithobates sylvaticus）中金属的积累。通过电感耦合等离子体质谱法测定了t体内除胃和肠外以及水中的整个变质高潮前后的金属水平。木蛙t在肠道线圈中浓缩了金属，伴随着高潮而迅速下降。在稀释的沥青污染环境中饲养的中钒，钼和镉的含量较高，但预计不会对发展造成负面影响。总而言之，木蛙t中的金属积累量根据变质高潮的发育阶段而有很大差异。研究发育无核幼虫的污染物时，必须考虑代谢变化和肠道重塑。