Laboratorio en Ecología Acuática y Monitoreo Ambiental, CEDESU, Universidad Autónoma de Campeche, Av. Héroe de Nacozari No. 480, 24070, San Francisco de Campeche, Campeche, Mexico.
Instituto EPOMEX, Universidad Autónoma de Campeche, Av. Héroe de Nacozari No. 480, 24070, San Francisco de Campeche, Campeche, Mexico.
Ecotoxicol Environ Saf. 2020 Jun 1;195:110477. doi: 10.1016/j.ecoenv.2020.110477. Epub 2020 Mar 19.
Bioindicator organisms are important tools in environmental monitoring studies. Understanding this, the overall goal of the present study was to evaluate the sensitivity and viability of the native fish species Banded tetra, (Astyanax aeneus; Günther, 1860), widely spread in the aquatic ecosystems of the Yucatan Peninsula in Mexico, as a bioindicator organism. In order to do this, we performed a bioassay at sublethal concentrations using copper (CuSO) to experimentally evaluate and validate the relationship between the trace metals and oxidative stress biomarkers response [(catalase (CAT), lipoperoxidation content (LPO)], detoxification [(glutathione S-transferase (GST), metallothionein content (MT)] and neurotoxicity (AChE) in muscle of A. aeneus. Results showed changes in biomarkers after 96 h: Catalase activity (CAT) was significantly higher above 1.5 and 2 mg/L (154.35 and 172.50% increase, respectively); lipid peroxidation contents (TBARS), GST activity, and MT content were very similar to CAT activity at 1.5 and 2 mg/L of Cu. In terms of neurotoxicity, AChE activity was significantly inhibited at 0.1 mg/L (64%; p < 0.001) and 0.5 mg/L (44%; p < 0.001) of Cu. Based on the bioassay results, we performed a trace metal monitoring campaign in muscle of A. aeneus caught in 15 sites with different anthropogenic activities, during the summer of 2017, to establish a baseline of trace metals pollution in the state of Campeche. A. aeneus showed the highest trace metal accumulation in the following order: Al > Fe > Mn > Zn > Cu > Hg > Cr > Pb > Cd > V > As, while sites were arrange as follows: Xnoha lagoon > Palizada River > Candelaria River > Ululmal > Maravillas > López Mateos. PCA showed a cluster between biomarkers (GST, CAT, TBARS, and MT) and concentration of metals (Cd, Cu, Fe, Zn, Hg and Cr). Conversely, AChE inhibition was not related to a specific metal, but highest inhibitions (>50%) were present in those sites with intensive agricultural practices. These results determined that, based on its physiological response and trace metal bioaccumulation, Astyanax aeneus can be considered a good bioindicator for evaluating the presence of trace metals in tropical aquatic systems of the Yucatan Peninsula.
生物标志物在环境监测研究中是重要的工具。有鉴于此，本研究的总体目标是评估广泛分布于墨西哥尤卡坦半岛水生生态系统中的本地鱼类——带纹脂鲤（Astyanax aeneus；Günther，1860）作为生物标志物的敏感性和生存能力。为此，我们使用铜（CuSO）在亚致死浓度下进行了生物测定，以实验评估和验证痕量金属与氧化应激生物标志物反应[（过氧化氢酶（CAT）、脂质过氧化含量（LPO）]、解毒[（谷胱甘肽 S-转移酶（GST）、金属硫蛋白含量（MT）]和肌肉神经毒性（AChE）之间的关系在 A. aeneus 中。结果表明，96 小时后生物标志物发生变化：过氧化氢酶活性（CAT）在 1.5 和 2 mg/L 以上显著升高（分别增加 154.35%和 172.50%）；脂质过氧化含量（TBARS）、GST 活性和 MT 含量在 1.5 和 2 mg/L 的 Cu 下与 CAT 活性非常相似。在神经毒性方面，AChE 活性在 0.1 mg/L（64%；p<0.001）和 0.5 mg/L（44%；p<0.001）的 Cu 下显著受到抑制。基于生物测定结果，我们在 2017 年夏季在具有不同人为活动的 15 个地点采集了 A. aeneus 的肌肉进行痕量金属监测，以建立坎佩切州痕量金属污染的基线。A. aeneus 对以下痕量金属的积累最高：Al>Fe>Mn>Zn>Cu>Hg>Cr>Pb>Cd>V>As，而地点排列如下：Xnoha 泻湖>Palizada 河>Candelaria 河>Ululmal>Maravillas>López Mateos。PCA 显示生物标志物（GST、CAT、TBARS 和 MT）和金属浓度（Cd、Cu、Fe、Zn、Hg 和 Cr）之间存在聚类。相反，AChE 抑制与特定金属无关，但在那些农业活动密集的地点，抑制率最高（>50%）。这些结果表明，根据其生理反应和痕量金属的生物积累，Astyanax aeneus 可以被认为是评估尤卡坦半岛热带水生系统中痕量金属存在的良好生物标志物。
