Abstract：
The use of effect biomarkers has contributed to the understanding of the sublethal effects of contaminants on different organisms. However, the analysis of genotoxic markers as an indicator of organism and environmental health in sharks is underexplored. Thus, the present study investigated the relationship between the genomic damage frequency in erythrocytes and metal(loid) concentrations in whole blood of three shark species (Galeocerdo cuvier, Negaprion brevirostris and Ginglymostoma cirratum), taking into account climatic seasonality. The results showed that G. cuvier, an apex predator, presented the highest total erythrocyte genomic damage frequencies together with the highest mean whole blood concentrations of Al, Cd, Cr, Fe, Mn, Ni, Pb and Zn. The shark N. brevirostris also presented high levels of metal(loid), indicating a greater susceptibility to these contaminants in species that preferentially feed on fish. In contrast, G. cirratum, a mesopredator, presented the lowest erythrocyte damage frequencies and whole blood metal(loid) concentrations. The presence of micronuclei was the most responsive biomarker, and Al, As and Zn had an important effect on the genomic damage frequencies for all species evaluated. Zn concentration influenced the binucleated cells frequencies and Al concentration had an effect on the total damage and micronuclei frequencies in G. cuvier and N. brevirostris. Binucleated cells and blebbed nuclei frequencies were affected by As concentration, especially in G. cirratum, while showing a strong and positive correlation with most of the metals analyzed. Nonetheless, baseline levels of metal(loid) blood concentrations and erythrocyte genomic damage frequencies in sharks have not yet been established. Therefore, minimum risk levels of blood contaminants concentrations on the health of these animals have also not been determined. However, the high genomic instability observed in sharks is of concern considering the current health status of these animals, as well as the quality of the environment studied.
摘要：
效应生物标志物的使用有助于理解污染物对不同生物体的亚致死效应。然而,作为鲨鱼生物和环境健康指标的基因毒性标记的分析还没有得到充分的探索。因此，本研究调查了三种鲨鱼物种的红细胞基因组损伤频率与全血中金属（类）浓度之间的关系（Galeocerdocuvier，短小神经节虫和小脑），考虑到气候季节性。结果表明，G.cuvier，顶级捕食者,呈现最高的总红细胞基因组损伤频率以及最高的Al平均全血浓度，Cd,Cr,Fe,Mn,Ni,Pb和Zn。鲨鱼N.brevirostris也表现出高水平的金属(loid)，表明优先以鱼类为食的物种对这些污染物的敏感性更高。相比之下,G.ciratum,中间捕食者，呈现最低的红细胞损伤频率和全血金属（类）浓度。微核的存在是最敏感的生物标志物，Al,As和Zn对评估的所有物种的基因组损伤频率都有重要影响。Zn浓度影响双核细胞的频率，Al浓度影响G.cuvier和N.brevirostris的总损伤和微核频率。双核细胞和出泡核频率受As浓度的影响，尤其是在G.ciratum，同时与所分析的大多数金属具有很强的正相关性。尽管如此，鲨鱼中金属(类)血液浓度和红细胞基因组损伤频率的基线水平尚未确定.因此,血液污染物浓度对这些动物健康的最低风险水平也尚未确定。然而,考虑到这些动物目前的健康状况，在鲨鱼中观察到的高度基因组不稳定性令人担忧，以及所研究的环境质量。
