Huss Magnus, Howeth Jennifer G, Osterman Julia I, Post David M
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA
Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA.
Proc Biol Sci. 2014 Jul 22;281(1787). doi: 10.1098/rspb.2014.0275. Epub 2014 Jun 11.
Evolutionary diversification within consumer species may generate selection on local ecological communities, affecting prey community structure. However, the extent to which this niche construction can propagate across food webs and shape trait variation in competing species is unknown. Here, we tested whether niche construction by different life-history variants of the planktivorous fish alewife (Alosa pseudoharengus) can drive phenotypic divergence and resource use in the competing species bluegill (Lepomis macrochirus). Using a combination of common garden experiments and a comparative field study, we found that bluegill from landlocked alewife lakes grew relatively better when fed small than large zooplankton, had gill rakers better adapted for feeding on small-bodied prey and selected smaller zooplankton compared with bluegill from lakes with anadromous or no alewife. Observed shifts in bluegill foraging traits in lakes with landlocked alewife parallel those in alewife, suggesting interspecific competition leading to parallel phenotypic changes rather than to divergence (which is commonly predicted). Our findings suggest that species may be locally adapted to prey communities structured by different life-history variants of a competing dominant species.
消费者物种内部的进化多样化可能会对当地生态群落产生选择作用，从而影响猎物群落结构。然而，这种生态位构建能够在食物网中传播并塑造竞争物种的性状变异的程度尚不清楚。在这里，我们测试了食浮游生物的鱼类——灰西鲱（Alosa pseudoharengus）的不同生活史变体所进行的生态位构建是否会驱动竞争物种蓝鳃太阳鱼（Lepomis macrochirus）的表型分化和资源利用。通过结合共同花园实验和比较性野外研究，我们发现，与来自有溯河洄游型灰西鲱或没有灰西鲱的湖泊中的蓝鳃太阳鱼相比，来自有陆封型灰西鲱湖泊的蓝鳃太阳鱼在以小型浮游动物而非大型浮游动物为食时生长得相对更好，其鳃耙更适合捕食小型猎物，并且会选择更小的浮游动物。在有陆封型灰西鲱的湖泊中观察到的蓝鳃太阳鱼觅食性状的变化与灰西鲱中的变化相似，这表明种间竞争导致了平行的表型变化而非分化（这是通常所预测的）。我们研究结果表明，物种可能会在当地适应由竞争优势物种的不同生活史变体构建的猎物群落。
