The deleterious effects of mercury (Hg) contamination are well documented in humans and wildlife. Chronic exposure via diet and maternal transfer are two pathways which increase the toxicological risk for wild populations. However, few studies examined the physiological impact of Hg in crocodilians. We investigated the Hg contamination in neonate Smooth-fronted Caimans, Paleosuchus trigonatus, and the use of keratinized tissues and blood to evaluate maternal transfer. Between November 2017 and February 2020, we sampled 38 neonates from 4 distinct nests. Mercury concentration was measured in claws, scutes and total blood. Highest Hg concentrations were found in claws. Strong inter-nest variations (Hg ranging from 0.17 ± 0.02 to 0.66 ± 0.07 μg.g^-1 dw) presumably reflect maternal transfer. Reduced body size in neonates characterized by elevated Hg concentrations suggests an influence of Hg during embryonic development. We emphasize the use of claws as an alternative to egg collection to investigate maternal transfer in crocodilians. Our results demonstrated the need of further investigation of the impact of Hg contamination in the first life stages of crocodilians.

汞（Hg）污染的有害影响在人类和野生动植物中已得到充分证明。通过饮食和母体转移引起的慢性暴露是增加野生种群毒理学风险的两条途径。但是，很少有研究检查汞对鳄鱼的生理影响。我们调查了新生儿平滑​​面凯门鳄，古豹trigonatus中的汞污染，以及使用角质化组织和血液评估母体转移。在2017年11月至2020年2月之间，我们从4个不同的巢中抽取了38位新生儿。测定了爪，瓢和全血中的汞浓度。爪中的汞含量最高。剧烈的巢间变化（Hg从0.17±0.02到0.66±0.07μg.g ^-1dw）可能反映了母亲的转移。以汞浓度升高为特征的新生儿体型缩小表明汞在胚胎发育过程中的影响。我们强调使用爪子代替鸡蛋收集来调查鳄鱼中的母体转移。我们的结果表明，有必要进一步调查汞污染在鳄鱼的第一生命阶段中的影响。