Bernhardt Richard R, von Hippel Frank A
Department of Biological Sciences, University of Alaska Anchorage, 3211 Providence Drive, Anchorage, AK 99508-4614, USA.
Behaviour. 2008;145(4-5):537-559. doi: 10.1163/156853908792451511.
We describe behavioural changes in two generations of threespine stickleback (Gasterosteus aculeatus) exposed to environmentally relevant concentrations of perchlorate. The first generation (G(0,2002)) was exposed as two-year-old adults to perchlorate in experimental groups ranging in concentration from less than the method detection limit (<1.1 ppb) to 18.6 ppm for up to 22 days during their courtship, spawning, egg guarding, and first five days of fry guarding. No differences were noted in the behaviour or reproductive output of these fish that were exposed as adults. However, perchlorate exposure throughout development caused widespread effects in the second generation (G(1,2003)), which was spawned and raised through sexual maturity in one of four nominal experimental groups (0, 30 and 100 ppm, and a 'variable' treatment that progressively increased from <1.1 ppb to approximately 60 ppm perchlorate). Dose-dependent effects were found during the G(1,2003)'s swimming and behavioural evaluations, including higher mortality rates among treated fish following stressful events. Perchlorate-exposed fish had higher failure rates during swimming trials and failed at lower flow rates than control fish. A number of treated fish exhibited seizures. Progressively fewer males completed benchmark metrics, such as nest building, spawning, nursery formation, or fry production, in a dose-dependent manner. Fewer males from higher treatments courted females, and those that did initiated courtship later and had a reduced behavioural repertoire compared to fish from lower treatments. The lowest observed adverse effect level (LOAEL) for swimming performance, reproductive behaviour, survivorship and recruitment was 30 ppm perchlorate (our lowest G(1,2003) treatment), and near complete inhibition of reproductive activity was noted among males raised in 100 ppm perchlorate. A small number of treated G(1,2003) females were isolated in aquaria, and some performed reproductive behaviour typical of males, such as biting, leading and zig-zagging in the presence of gravid females. These findings have profound implications for recruitment in wild fish populations exposed to perchlorate, and suggest that perchlorate may disrupt behaviour in other vertebrates as well.
我们描述了两代三刺鱼（Gasterosteus aculeatus）在暴露于环境相关浓度高氯酸盐后的行为变化。第一代（G(0,2002)）在求偶、产卵、护卵以及幼鱼保护的前五天期间，作为两岁的成年鱼暴露于浓度范围从低于方法检测限（<1.1 ppb）到18.6 ppm的高氯酸盐实验组中，暴露时间长达22天。这些成年期暴露的鱼在行为或繁殖产出方面未观察到差异。然而，在整个发育过程中暴露于高氯酸盐对第二代（G(1,2003)）产生了广泛影响，第二代在四个名义实验组之一（0、30和100 ppm，以及从<1.1 ppb逐渐增加到约60 ppm高氯酸盐的“可变”处理组）中产卵并饲养至性成熟。在G(1,2003)的游泳和行为评估中发现了剂量依赖性效应，包括应激事件后处理组鱼的死亡率更高。暴露于高氯酸盐的鱼在游泳试验中的失败率更高，并且在比对照鱼更低的流速下就失败了。一些处理组的鱼出现了癫痫发作。越来越少的雄鱼以剂量依赖性方式完成筑巢、产卵、育儿所形成或幼鱼生产等基准指标。来自高剂量处理组的雄鱼求偶的较少，并且与低剂量处理组的鱼相比，那些求偶的雄鱼开始求偶的时间更晚，行为模式也有所减少。游泳性能、繁殖行为、存活率和补充率的最低观察到的有害作用水平（LOAEL）为30 ppm高氯酸盐（我们G(1,2003)的最低处理组），并且在100 ppm高氯酸盐中饲养的雄鱼中观察到繁殖活动几乎完全受到抑制。少数处理组的G(1,2003)雌鱼被隔离在水族箱中，一些表现出典型的雄鱼繁殖行为，如在有孕雌鱼时咬、引导和曲折游动。这些发现对暴露于高氯酸盐的野生鱼类种群的补充具有深远影响，并表明高氯酸盐也可能扰乱其他脊椎动物的行为。
