Fish trophic divergence along a lake productivity gradient revealed by historic patterns of invasion and eutrophication
Fish trophic divergence along a lake productivity gradient revealed by historic patterns of invasion and eutrophication
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入侵和富营养化的历史模式揭示了沿湖泊生产力梯度的鱼类营养差异
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发表时间：
2013
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影响因子：
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通讯作者：
M. Kinnison
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作者：
Quenton M. Tuckett;K. Simon;J. Saros;David B. Halliwell;M. Kinnison
总结
对鱼类和其他生物体营养分化的研究强调资源可用性是一个驱动因素，但通常是在特定资源有限系统内的替代资源方面。相比之下，整体生态系统生产力在形成系统间营养多样性方面的作用却很少受到关注。
生产力梯度的差异可能是相关的，因为水生系统跨越了一系列生产力，人类正在加速富营养化的自然过程，生产力控制着控制替代资源的可用性和成本/效益的社区和生态系统过程。
在这里，我们研究了白鲈（Morone americana）种群在与营养分歧相关的特征上是否存在差异，以及如何通过湖泊生产力的景观模式来预测这种变化。
白鲈种群的身体尺寸、鳍长度和鳃耙结构各不相同。这些特征中的每一个都显示出与塞基湖深度和其他湖泊生产力指标显着且通常很强的相关性（r2高达0.91），因此来自富营养化系统的白鲈往往更大，有更多的凸体，更长的鳍，更多的近末端嘴和间距更大的鳃耙。同位素 15N 与表型趋异相关，来自富营养化系统的鱼类在较小尺寸时表现出营养转变。
我们的结果表明，生产力具有预测景观尺度性状变化的惊人能力。事实上，许多研究种群是在上个世纪建立的，并且一些湖泊在那个时期变得富营养化，这表明鱼类的营养性状可以对湖泊条件做出快速反应。
Summary
Studies of trophic divergence in fishes and other organisms emphasise resource availability as a driving factor, but usually in terms of alternate resources within particular resource-limited systems. In contrast, the role of overall ecosystem productivity in shaping trophic diversity among systems has received less attention.
Divergence along productivity gradients may be relevant because aquatic systems span a range of productivities, humans are accelerating the natural process of eutrophication, and productivity controls community and ecosystem processes that govern the availability and costs/benefits of alternative resources.
Here, we study whether populations of white perch (Morone americana) differ in traits related to trophic divergence and how such variation might be predicted by landscape patterns of lake productivity.
White perch populations differed in their body dimensions, fin lengths and gill raker structures. Each of these traits showed significant and often strong (r2 up to 0.91) correlations with lake Secchi depth and other metrics of lake productivity, such that white perch from more eutrophic systems tended to be larger, have more gibbous bodies, longer fins, more subterminal mouths and gill rakers with greater spacing. Isotopic 15N was correlated with phenotypic divergence, and fish from eutrophic systems exhibited a trophic shift at smaller sizes.
Our results suggest that productivity has surprising ability to predict trait variation at the landscape scale. The fact that a number of the study populations were established in the last century and that some lakes became eutrophic in that period, suggests fish trophic traits can respond quickly to lake conditions.