Rising CO2 concentrations affect settlement behaviour of larval damselfishes
Rising CO2 concentrations affect settlement behaviour of larval damselfishes
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DOI：
10.1007/s00338-011-0837-0
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发表时间：
2012-03-01
期刊：
影响因子：
3.5
通讯作者：
Jones, G. P.
中科院分区：
文献类型：
--
作者：
Devine, B. M.;Munday, P. L.;Jones, G. P.
珊瑚鱼幼体主动选择首选的底栖生物栖息地，依靠嗅觉、视觉和听觉线索来区分定居时的微生境。最近的研究表明，暴露在高浓度二氧化碳(CO2)中会损害幼年珊瑚鱼的嗅觉线索识别。然而，这是否改变了鱼类的定居行为或扰乱了栖息地的选择尚不清楚。在这里，在栖息地利用模式不同的三种菊鱼(Pomacentridae科)中，测试了二氧化碳浓度升高对幼体行为和栖息地选择的影响：Pomacentus bobinensis(栖息地通才)、Pomacentus chrysurus(瓦砾专家)和Pomacentus moluccensis(活珊瑚专家)。安置期的幼虫暴露在当前的二氧化碳水平或二氧化碳浓度下，根据IPCC的排放情景，到2100年(700和850ppm)可能会发生这种情况。首先，使用双通道水槽进行配对选择测试，以测试硬珊瑚、软珊瑚和珊瑚碎石栖息地之间的嗅觉辨别能力。然后，通过一夜之间进行的多项选择定居实验，比较了不同处理之间的沉淀鱼选择的栖息地。最后，对其中一种金龟子的不同处理之间的定居时间进行了两个月周期的比较。在嗅觉试验中，暴露在高浓度二氧化碳中会破坏幼虫辨别栖息地气味的能力。然而，当所有感官线索都可用时，这对定居时选择的栖息地没有影响。二氧化碳暴露显著改变了鱼类的沉降时间，对照鱼在新月前后表现出最高的沉降速度，而暴露于850ppm二氧化碳的鱼类在满月前后表现出最高的沉降速率。这些结果表明，在小空间尺度上选择栖息地时，幼虫可以依靠其他感官信息，如视觉线索，来补偿嗅觉能力的受损。然而，二氧化碳的增加可能会导致幼虫在不利的时间定居，这可能会对幼虫的生存和种群补充造成影响。
Reef fish larvae actively select preferred benthic habitat, relying on olfactory, visual and acoustic cues to discriminate between microhabitats at settlement. Recent studies show exposure to elevated carbon dioxide (CO2) impairs olfactory cue recognition in larval reef fishes. However, whether this alters the behaviour of settling fish or disrupts habitat selection is unknown. Here, the effect of elevated CO2 on larval behaviour and habitat selection at settlement was tested in three species of damselfishes (family Pomacentridae) that differ in their pattern of habitat use: Pomacentrus amboinensis (a habitat generalist), Pomacentrus chrysurus (a rubble specialist) and Pomacentrus moluccensis (a live coral specialist). Settlement-stage larvae were exposed to current-day CO2 levels or CO2 concentrations that could occur by 2100 (700 and 850 ppm) based on IPCC emission scenarios. First, pair-wise choice tests were performed using a two-channel flume chamber to test olfactory discrimination between hard coral, soft coral and coral rubble habitats. The habitat selected by settling fish was then compared among treatments using a multichoice settlement experiment conducted overnight. Finally, settlement timing between treatments was compared across two lunar cycles for one of the species, P. chrysurus. Exposure to elevated CO2 disrupted the ability of larvae to discriminate between habitat odours in olfactory trials. However, this had no effect on the habitats selected at settlement when all sensory cues were available. The timing of settlement was dramatically altered by CO2 exposure, with control fish exhibiting peak settlement around the new moon, whereas fish exposed to 850 ppm CO2 displaying highest settlement rates around the full moon. These results suggest larvae can rely on other sensory information, such as visual cues, to compensate for impaired olfactory ability when selecting settlement habitat at small spatial scales. However, rising CO2 could cause larvae to settle at unfavourable times, with potential consequences for larval survival and population replenishment.