Threespine stickleback (Gasterosteus aculeatus) populations that have evolved pelvic girdle reduction are most commonly found in lakes with low dissolved ion concentration, a lack of piscivorous fishes, and abundant macroinvertebrate predators. Researchers have speculated that macroinvertebrates have a propensity to consume prey with pelvic spines. If this is true, perhaps macroinvertebrates use the stickleback's spines to facilitate capture and manipulation. This study tested whether dragonfly naiads differentially prey upon stickleback possessing either a complete or reduced pelvis and documented naiad hunting and capturing behavior. Results from an arena experiment suggest that naiads do not prey more heavily upon individuals with one pelvic phenotype over the other. However, results from trials where the naiads were presented with one stickleback with pelvic spines and another without suggest that naiads prey more heavily upon small stickleback with pelvic spines and large stickleback without pelvic spines and that they adjust their predatory behavior based upon the pelvic phenotype of the prey.

中文翻译：

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蜻蜓水母对三刺刺鱼的捕食


已经进化出骨盆带缩小的三刺刺鱼（Gasterosteus aculeatus）种群最常见于溶解离子浓度低、缺乏食鱼鱼类和大型无脊椎动物捕食者丰富的湖泊中。研究人员推测，大型无脊椎动物有捕食带有骨盆棘的猎物的倾向。如果这是真的，也许大型无脊椎动物利用刺鱼的刺来方便捕获和操纵。这项研究测试了蜻蜓水虫是否会以不同的方式捕食骨盆完整或缩小的刺鱼，并记录了水虫的狩猎和捕获行为。竞技场实验的结果表明，水母对具有一种骨盆表型的个体的捕食程度并不比对另一种骨盆表型的个体的捕食程度高。然而，试验结果显示，水虫们分别喂食一只有骨盆刺的刺鱼和另一只没有骨盆刺的刺鱼，结果表明，水虫们更多地捕食有骨盆刺的小刺鱼和没有骨盆刺的大刺鱼，并且它们会根据刺鱼的骨盆表型来调整其捕食行为。猎物。