Quantitative analysis of dental microwear in threespine stickleback: a new approach to analysis of trophic ecology in aquatic vertebrates
Quantitative analysis of dental microwear in threespine stickleback: a new approach to analysis of trophic ecology in aquatic vertebrates
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DOI：
10.1111/j.1365-2656.2006.01116.x
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发表时间：
2006-07-01
影响因子：
4.8
通讯作者：
Bell, MA
中科院分区：
文献类型：
--
作者：
Purnell, MA;Hart, PJB;Bell, MA
1.三刺鱼是研究基因组和表型进化、适应和物种形成的重要模式生物。腹骨化石提供了在真实进化时间尺度上测试从现存鱼类研究中得出的模型的可能性。例如，对食物资源的竞争在刺鱼物种形成中发挥了重要作用，导致了食物采集特征和生态特征置换的差异，但不可能在化石中测试这一模型，因为饮食的证据几乎从来没有保存过。我们在这里展示了牙齿微磨损的定量分析，这是一项以前仅适用于哺乳动物的技术，为刺鱼的饮食偏好提供了可靠的指导。在实验室条件下饲养的刺鱼的牙齿表现出微磨损模式，这种模式根据底物的粗糙度以及鱼类是以水柱内的水蚤为食还是以底部的摇蚊幼虫为食而系统地变化。此外，微磨损数据显示，它们的分布有一个渐进的变化，跟踪了实验性喂养处理的差异。野生种群中的微穿戴也与摄食有关。在基于微磨损模式的营养生态位盲目评估中，我们能够正确地将除一个不确定的种群外的所有种群分配到营养类群。来自野生刺鱼的微磨损数据显示，分布的变化与实验室中观察到的处理范围内的分布相媲美，这使得种群可以根据它们接近完全海底或完全边缘取食的程度进行排序。我们的结果表明，微磨损在鱼类营养生态分析中具有潜在的潜力，特别是在物种对和生态位分化的分析中。与通过分析胃内容物提供的营养快照相比，它具有优势，因为微型服装反映了较长时间内的喂养和食物偏好，并且可以应用于无法获得这些数据的地方。此外，它还适用于已灭绝的生物和化石，使营养生态学、生态位划分和进化时间尺度上的竞争的作用首次得到研究。
1. The threespine stickleback Gasterosteus aculeatus is an important model organism in studies of genomic and phenotypic evolution, adaptation and speciation. Fossil Gasterosteus offer the potential to test models derived from studies of extant fishes over true evolutionary time-scales. Competition for food resources, for example, plays an important part in stickleback speciation, causing divergence in food gathering traits and ecological character displacement, but it is not possible to test this model in fossils because evidence of diet is almost never preserved.2. We demonstrate here that quantitative analysis of dental microwear, a technique previously applied only to mammals, provides a reliable guide to the dietary preferences of stickleback. Teeth from stickleback raised under laboratory conditions exhibit microwear patterns that vary systematically according to substrate coarseness and whether fishes feed on Daphnia within the water column, or on chironomid larvae from the bottom. Furthermore, microwear data exhibit a progressive shift in their distribution that tracks differences in experimental feeding treatments.3. Microwear in wild populations also exhibits a relationship with feeding. In blind assessments of trophic niche based on microwear patterns we were able to correctly assign all but one equivocal population to trophic group. Microwear data from wild stickleback exhibit a shift in distribution comparable with that observed across the range of treatments in the laboratory and these allow populations to be ranked according to the degree to which they approach fully benthic or fully limnetic feeding.4. Our results demonstrate that microwear has the potential to be a powerful tool in the analysis of fish trophic ecology, particularly in the analysis of species pairs and niche differentiation. It has advantages over the trophic snapshot provided by analysis of stomach contents in that microwear reflects feeding and food preferences over a longer period of time, and can be applied where these data are unavailable. Furthermore, it is applicable to extinct organisms and fossils, allowing the role of trophic ecology, niche partitioning and competition over evolutionary time-scales to be investigated for the first time.