Effects of prey quality and predator body size on prey DNA detection success in a centipede predator

Predator body size and prey quality are important factors driving prey choice and consumption rates. Both factors might affect prey detection success in PCR-based gut content analysis, potentially resulting in over- or underestimation of feeding rates. Experimental evidence, however, is scarce. We examined how body size and prey quality affect prey DNA detection success in centipede predators. Due to metabolic rates increasing with body size, we hypothesized that prey DNA detection intervals will be significantly shorter in large predators than in smaller ones. Moreover, we hypothesized that prey detection intervals of high-quality prey will be shorter than in low-quality prey due to faster assimilation. Small, medium and large individuals of Lithobius spp., abundant generalist predators in forest litter layers, were fed with Collembola and allowed to digest their prey for up to 168 h post-feeding. Additionally, medium-sized lithobiids were fed with either Diptera or Lumbricidae prey. N...捕食者体型与猎物品质是驱动猎物选择及摄食速率的关键影响因素。二者均可能对基于聚合酶链式反应（PCR）的肠道内容物分析中的猎物DNA检测成功率产生影响，进而可能导致摄食速率的高估或低估。然而目前相关实验证据仍较为匮乏。 本研究以蜈蚣类捕食者为研究对象，探究体型与猎物品质对猎物DNA检测成功率的作用效应。鉴于代谢速率随体型增大而升高，我们提出假说：大型捕食者的猎物DNA检测窗口期将显著短于小型个体。此外，我们还提出另一假说：由于同化速率更快，高品质猎物的检测窗口期将短于低品质猎物。 本研究选取森林枯落层中广布的广食性捕食者石蜈蚣属（Lithobius spp.）的小型、中型及大型个体，以弹尾纲（Collembola）为猎物进行饲喂，并设置摄食后最长168小时的消化时长梯度。此外，中型石蜈蚣个体还分别以双翅目（Diptera）或正蚓科（Lumbricidae）猎物饲喂。N...