Aarhus University, Institute of Bioscience, Vejlsøvej 25, 8600 Silkeborg, Denmark.
Aquat Toxicol. 2013 Sep 15;140-141:340-5. doi: 10.1016/j.aquatox.2013.06.019. Epub 2013 Jun 29.
In this study, we aimed to evaluate the effects of a short pulse exposure of the pyrethroid lambda-cyhalothrin (LC) on the predator and anti-predator behaviour of the same species; Gammarus pulex. Predator behaviour, at the level of the individual, was studied in indoor microcosms using video tracking equipment during simultaneous exposure of the predator (G. pulex) and its prey (Leuctra nigra) during 90 min exposure of 1, 6.6 or 62.1 ngL(-1) LC. During an initial 30 min of exposure, the predator and prey organisms were maintained physically separated, and the actual interaction was studied through the subsequent 60 min of exposure. The anti-predator behaviour of G. pulex (drift suppression in response to the presence of brown trout) was studied in outdoor stream channels during a 90 min pulse exposure to LC (7.4 or 79.5 ngL(-1)) with, or without, brown trout. Based on survival curves for L. nigra we found that the mortality rate for L. nigra significantly decreased during exposure to 6.6 and 62.1 ngL(-1) LC (P<0.05 and P<0.001, respectively). We found no significant effects suggesting that G. pulex was repelled by contaminated prey items (P>0.05). We found that the exposure of G. pulex to 7.4 and 79.5 ngL(-1) LC significantly increased drift (from ∼0% to ∼100% in both treatments; P<0.001) independent of the presence of brown trout (P<0.05). In other words, the natural anti-predator behaviour of G. pulex was overruled by the stress response to LC exposure increasing G. pulex predation risk from drift feeding brown trouts. Our results show that the anti-predator and predator behaviour of G. pulex were significantly changed during exposure to very low and environmentally realistic LC concentrations and exposure duration. The potential implications for the field scenario are discussed.
在这项研究中，我们旨在评估拟除虫菊酯 lambda-氯氰菊酯（LC）短脉冲暴露对同一物种（秀丽隐杆线虫）捕食者和抗捕食者行为的影响。使用视频跟踪设备，在室内微宇宙中研究个体捕食者行为，同时暴露捕食者（秀丽隐杆线虫）及其猎物（Leuctra nigra），暴露时间为 90 分钟，LC 浓度分别为 1、6.6 或 62.1ng/L。在暴露的前 30 分钟内，将捕食者和猎物生物体物理分离，并在随后的 60 分钟暴露期间研究实际相互作用。在 90 分钟的 LC（7.4 或 79.5ng/L）脉冲暴露期间，在户外溪流通道中研究了秀丽隐杆线虫的抗捕食者行为（对褐鳟存在的漂移抑制），并在有或没有褐鳟的情况下进行。根据 L. nigra 的生存曲线，我们发现 L. nigra 的死亡率在暴露于 6.6 和 62.1ng/L LC 时显著降低（P<0.05 和 P<0.001）。我们没有发现任何表明秀丽隐杆线虫被受污染的猎物排斥的显著影响（P>0.05）。我们发现，秀丽隐杆线虫暴露于 7.4 和 79.5ng/L LC 显著增加了漂移（在两种处理中均从约 0%增加到约 100%；P<0.001），而与褐鳟的存在无关（P<0.05）。换句话说，LC 暴露引起的应激反应削弱了秀丽隐杆线虫的自然抗捕食者行为，从而增加了秀丽隐杆线虫通过漂移捕食褐鳟的捕食风险。我们的研究结果表明，秀丽隐杆线虫的抗捕食者和捕食者行为在暴露于非常低和现实环境 LC 浓度和暴露时间时发生了显著变化。讨论了对现场情况的潜在影响。
