Size structuring and allometric scaling relationships in coral reef fishes
Size structuring and allometric scaling relationships in coral reef fishes
复制标题
珊瑚礁鱼类的体型结构和异速生长关系
DOI：
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发表时间：
2017
影响因子：
4.8
通讯作者：
J. Baum
中科院分区：
文献类型：
--
作者：
Jillian C. Dunic;J. Baum
温带海洋鱼类群落通常具有大小结构，捕食者消耗越来越大的猎物，并在生长过程中以更高的营养水平进食。间隙限制和个体发育的饮食变化的大小结构出现在这些社区的关键机制。然而，人们对珊瑚礁鱼类的大小结构知之甚少。在这里，我们的目标是通过检查两组珊瑚礁捕食者中这些机制的证据来加深对珊瑚礁食物网大小结构的了解。鉴于珊瑚礁鱼类之间的进食模式的多样性，我们还比较了不同功能组的张口大小身体大小异速生长关系，以确定它们是否是可靠的指标大小结构。我们使用肠道内容物分析和分位数回归捕食者大小猎物大小的关系，测试的证据，在礁鱼（n = 13种）和底栖动物（n = 3种）的张口限制和个体发生生态位的转变。然后，我们估计了21个不同的物种从四个功能组，包括食草动物/食肉动物，预计不会被间隙限制的张口大小身体大小异速生长的比例系数。我们发现的证据，这两种机制的大小结构在珊瑚礁piscivores，与最大猎物的大小缩放积极与捕食者的身体大小，和个体发育的饮食变化，包括猎物类型和扩大猎物的大小。然而，几乎没有证据表明底栖无脊椎动物的大小结构。在物种和功能组，绝对和相对的张口尺寸是最大的鱼，如预期的，但张口尺寸的身体大小缩放关系并不表示大小结构。相反，相对张口的大小和嘴的形态可能是更好的指标。我们的研究结果提供的证据表明，珊瑚礁鱼类的大小结构和gape限制和个体发育生态位的变化是这种结构产生的机制。虽然张口异速生长并不表示大小结构，它可能对生态系统功能的影响：积极异速生长的张口大小，身体大小的比例关系在食草动物/食肉动物表明，这些物种的大型个体的损失将有不成比例的负面影响，对珊瑚礁放牧压力。
Temperate marine fish communities are often size-structured, with predators consuming increasingly larger prey and feeding at higher trophic levels as they grow. Gape limitation and ontogenetic diet shifts are key mechanisms by which size structuring arises in these communities. Little is known, however, about size structuring in coral reef fishes. Here, we aimed to advance understanding of size structuring in coral reef food webs by examining the evidence for these mechanisms in two groups of reef predators. Given the diversity of feeding modes amongst coral reef fishes, we also compared gape size-body size allometric relationships across functional groups to determine whether they are reliable indicators of size structuring. We used gut content analysis and quantile regressions of predator size-prey size relationships to test for evidence of gape limitation and ontogenetic niche shifts in reef piscivores (n = 13 species) and benthic invertivores (n = 3 species). We then estimated gape size-body size allometric scaling coefficients for 21 different species from four functional groups, including herbivores/detritivores, which are not expected to be gape-limited. We found evidence of both mechanisms for size structuring in coral reef piscivores, with maximum prey size scaling positively with predator body size, and ontogenetic diet shifts including prey type and expansion of prey size. There was, however, little evidence of size structuring in benthic invertivores. Across species and functional groups, absolute and relative gape sizes were largest in piscivores as expected, but gape size-body size scaling relationships were not indicative of size structuring. Instead, relative gape sizes and mouth morphologies may be better indicators. Our results provide evidence that coral reef piscivores are size-structured and that gape limitation and ontogenetic niche shifts are the mechanisms from which this structure arises. Although gape allometry was not indicative of size structuring, it may have implications for ecosystem function: positively allometric gape size-body size scaling relationships in herbivores/detritivores suggests that loss of large-bodied individuals of these species will have a disproportionately negative impact on reef grazing pressure.
影响因子：
4.8
作者：
Barnes, Carolyn;Maxwell, David;Jennings, Simon
通讯作者：
Jennings, Simon