Ord Terry J, Summers Thomas C, Noble Mae M, Fulton Christopher J
Am Nat. 2017 May;189(5):570-579. doi: 10.1086/691155. Epub 2017 Mar 2.
An ecological release from competition or predation is a frequent adaptive explanation for the colonization of novel environments, but empirical data are limited. On the island of Rarotonga, several blenny fish species appear to be in the process of colonizing land. Anecdotal observations have implied that aquatic predation is an important factor in prompting such amphibious fish behavior. We provide evidence supporting this hypothesis by demonstrating that amphibious blennies shift their abundance up and down the shoreline to remain above predatory fishes that periodically move into intertidal areas during high tide. A predation experiment using blenny mimics confirmed a high risk of aquatic predation for blennies, significantly higher than predation experienced on land. These data suggest that predation has played an active role in promoting terrestrial activity in amphibious blennies and provide a rare example of how ecological release from predation could drive the colonization of a novel environment.
竞争或捕食导致的生态释放是对新环境定殖的一种常见适应性解释，但实证数据有限。在拉罗汤加岛，几种鳚鱼似乎正处于向陆地定殖的过程中。轶事观察表明，水生捕食是促使这种两栖鱼类行为的一个重要因素。我们通过证明两栖鳚鱼会在海岸线上下改变其数量，以保持在高潮时定期进入潮间带区域的捕食性鱼类之上，从而提供了支持这一假设的证据。一项使用鳚鱼模型的捕食实验证实，鳚鱼面临着较高的水生捕食风险，显著高于在陆地所面临的捕食风险。这些数据表明，捕食在促进两栖鳚鱼的陆地活动方面发挥了积极作用，并提供了一个罕见的例子，说明捕食导致的生态释放如何推动对新环境的定殖。
