Can mixtures of cyanotoxins represent a risk to the zooplankton? The case study of Daphnia magna Straus exposed to hepatotoxic and neurotoxic cyanobacterial extracts
Can mixtures of cyanotoxins represent a risk to the zooplankton? The case study of Daphnia magna Straus exposed to hepatotoxic and neurotoxic cyanobacterial extracts
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DOI：
10.1016/j.hal.2013.11.004
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发表时间：
2014-01-01
期刊：
影响因子：
6.6
通讯作者：
Loureiro, Susana
中科院分区：
文献类型：
--
作者：
Freitas, Emanuela Cristina;Pinheiro, Carlos;Loureiro, Susana
在世界范围内，蓝藻水华的强度和频率一直在增加，有毒的蓝藻有时在许多淡水水体中占主导地位。由于在淡水环境中一种以上的蓝藻毒素共存是一种常见的现象，对这些毒素的联合影响进行研究将非常有用。在这项研究中，单一和两个氰毒素的不同模式的行动（肝毒性和神经毒性）的生存（致死暴露）和喂养（亚致死暴露）的枝水蚤大型的影响进行了调查。单次暴露，观察到水蚤的生存和摄食活动都受到环境相关浓度的肝毒性和神经毒性提取物的损害。在组合暴露中，存活率和摄食率终点均显示出与独立作用模型的良好拟合。对于摄食抑制试验中的急性试验和24小时暴露期，肝毒性和神经毒性提取物的组分之间没有相互作用，尽管在摄食率中可以看到轻微的协同偏差趋势。另一方面，对于暴露后4小时的时间段，在所有混合物浓度测试的摄食率中发现了协同偏差。因此，在对淡水水体进行风险评估时，还应考虑到肝毒素和神经毒素的合并接触，因为这些毒素的混合物对水蚤的摄食造成的接触后影响可能比单一接触的预期影响之和更为严重。(C)2013爱思唯尔有限公司版权所有。
Worldwide, cyanobacterial blooms have been increasing in intensity and frequency, with toxic cyanobacteria sometimes dominant throughout the year in many freshwater bodies. Since the coexistence of more than one type of cyanotoxins in freshwater environments is a common phenomenon, studies on the joint effects of these toxins would be very useful. In this study, the single and combined effects of two cyanotoxins with different modes of action (hepatotoxic and neurotoxic) on the survival (lethal exposure) and feeding (sublethal exposure) of the cladoceran Daphnia magna were investigated. With the single exposures, it was observed that both the survival and feeding activity of the daphnids were impaired by the hepatotoxic and neurotoxic extracts at environmentally relevant concentrations. In the combined exposures, both survival and feeding rate endpoints showed a good fit to the independent action model. For the acute assay and 24 h exposure period in the feeding inhibition test, there was no interaction between components of the hepatotoxic and neurotoxic extracts, although a slight tendency to a synergistic deviation could be seen in the feeding rates. On the other hand, for the 4 h post-exposure period, a synergistic deviation was found in feeding rates at all mixture concentrations tested. Hence, the combined exposure of hepatotoxins and neurotoxins should also be taken into account in risk assessments of freshwater bodies, since the mixture of these toxins can result in more severe post-exposure effects on the feeding of daphnids than the sum of those expected for single exposures. (C) 2013 Elsevier B.V. All rights reserved.