The recently described Squalus albicaudus is a mesopredator shark and, as such, exposed to mercury biomagnification processes. Therefore, this study aimed to assess total Hg (THg) concentrations in S. albicaudus, a deep-water species, sampled off Southeastern Brazil and discuss ecological, reproductive, human consumption and conservation implications. Thirty-two individuals were sampled off the coast of Rio de Janeiro, including 13 gravid females carrying 34 embryos. Muscle THg concentrations were higher in all sex classes compared to liver, gonads and brain. The last three, in turn, presented THg concentrations above toxic biota thresholds. Significant correlations were observed between muscle and brain and liver, indicating systemic Hg contamination and inter-organ transport and distribution. In addition, correlations observed between organs strongly support efficient Hg blood-brain barrier crossing and maternal transfer. Maternal THg transfer was observed, with embryo THg also above toxic thresholds for fish. THg levels in muscle and liver, as well as embryos, were higher compared to other Squalus species worldwide. Hg contamination off the coast of Rio de Janeiro is of significant concern and should be further assessed. Potential human consumption risks are noted, as muscle THg concentrations were above maximum permissible levels set by regulatory agencies.

中文翻译：

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最近描述的巴西白尾dog鱼Squalus albicaudus（Squalidae，Chondrichthyes）中的汞污染。

最近描述的Squalus albicaudus是中鲨鱼，因此暴露于汞生物放大过程中。因此，本研究旨在评估巴西东南部采样的深水物种白念珠菌中的总Hg（THg）浓度，并讨论其对生态，生殖，人类消费和保护的影响。在里约热内卢沿岸抽取了32个人，包括13名怀胎的雌性，携带了34个胚胎。与肝脏，性腺和大脑相比，所有性别类别的肌肉THg浓度都更高。反过来，最后三个代表的THg浓度高于有毒生物阈值。在肌肉与大脑和肝脏之间观察到显着相关性，表明系统性汞污染以及器官间运输和分布。此外，器官之间观察到的相关性有力地支持了有效的Hg血脑屏障穿越和母体转移。观察到母体THg转移，胚胎THg也高于鱼类的毒性阈值。肌肉，肝脏以及胚胎中的THg水平高于世界各地的其他Squalus物种。里约热内卢沿岸的汞污染令人严重关切，应进一步评估。指出了潜在的人类食用风险，因为肌肉中的THg浓度高于监管机构设定的最大允许水平。里约热内卢沿岸的汞污染令人严重关切，应进一步评估。指出了潜在的人类食用风险，因为肌肉中的THg浓度高于监管机构设定的最大允许水平。里约热内卢沿岸的汞污染令人严重关切，应进一步评估。指出了潜在的人类食用风险，因为肌肉中的THg浓度高于监管机构设定的最大允许水平。