Department of Integrative Biology, Oregon State University, Corvallis, Oregon, 97331, USA.
Ecology. 2017 Apr;98(4):896-902. doi: 10.1002/ecy.1732.
During major life-history transitions, animals often experience high mortality rates due to predation, making predator avoidance particularly advantageous during these times. There is mixed evidence from a limited number of studies, however, regarding how predator presence influences settlement of coral-reef fishes and it is unknown how other potentially mediating factors, including predator origin (native vs. nonnative) or interactions among conspecific recruits, mediate the non-consumptive effects of predators on reef fish settlement. During a field experiment in the Caribbean, approximately 52% fewer mahogany snapper (Lutjanus mahogoni) recruited to reefs with a native predator (graysby grouper, Cephalopholis cruentata) than to predator-free control reefs and reefs with an invasive predator (red lionfish, Pterois volitans) regardless of predator diet. These results suggest that snapper recruits do not recognize nonnative lionfish as a threat. However, these effects depended on the density of conspecific recruits, with evidence that competition may limit the response of snapper to even native predators at the highest recruit densities. In contrast, there was no effect of predator presence or conspecific density on the recruitment of bicolor damselfish (Stegastes partitus). These context-dependent responses of coral-reef fishes to predators during settlement may influence individual survival and shape subsequent population and community dynamics.
在重大的生活史转折期间，动物由于捕食而经常经历高死亡率，因此在这些时期避免捕食者特别有利。然而，来自少数研究的证据是混合的，关于捕食者的存在如何影响珊瑚礁鱼类的定殖，并且不知道其他潜在的中介因素，包括捕食者的起源（本地与非本地）或同种幼鱼之间的相互作用，如何调节捕食者对珊瑚鱼定殖的非消耗性影响。在加勒比地区的一项现场实验中，与无捕食者对照礁和有入侵性捕食者（红狮子鱼，Pterois volitans）的礁相比，有本地捕食者（灰鲷石斑鱼，Cephalopholis cruentata）的礁上，桃花鱼（Lutjanus mahogoni）的幼鱼定殖数量减少了约 52%。这些结果表明，幼鱼不会将非本地的狮子鱼视为威胁。然而，这些影响取决于同种幼鱼的密度，有证据表明，即使在最高幼鱼密度下，竞争也可能限制幼鱼对本地捕食者的反应。相比之下，捕食者的存在或同种幼鱼的密度对双色雀鲷（Stegastes partitus）的定殖没有影响。珊瑚礁鱼类在定殖期间对捕食者的这种依赖于环境的反应可能会影响个体的生存，并塑造随后的种群和群落动态。
