Tropical Aquaculture Laboratory, Program in Fisheries and Aquatic Sciences, School of Forest Resources and Conservation, University of Florida, Ruskin, Florida, 33570, USA.
Department of Life Sciences, The University of the West Indies, St Augustine, Trinidad and Tobago.
Ecology. 2021 Aug;102(8):e03411. doi: 10.1002/ecy.3411. Epub 2021 Jul 18.
Biotic resistance is often posited, but rarely known, to be the cause of invasion failure. Competition and predation are the most frequently identified processes that may prevent or limit the establishment of nonnative species. Interactions between nonnative and native species that involve intraguild predation (IGP) are very common in nature, although theory predicts most IGP systems should be unstable and lead to extinction. If this prediction is true, the frequency of invasion failures due to IGP may be underappreciated because of their fleeting nature and, thus, studies of unstable IGP systems are lacking, despite the opportunities they offer for understanding the factors affecting their unstable dynamics. We investigated a failed invasion involving an IGP relationship. In Florida, the guppy (Poecilia reticulata), a worldwide invader, fails to establish in the presence of eastern mosquitofish (Gambusia holbrooki). We tested whether and how resident mosquitofish cause guppy invasion failure using replicated mesocosm and aquarium trials. Both the predator and competitor components of the IGP relationship were strongly asymmetrical, with large impacts on guppies. We identified two effects, direct consumption of neonates and aggressive interference competition, that limited survival and recruitment. The highly unstable nature of this IGP relationship is the primary cause of the failure of the guppy to establish in Florida. Our study shows that the transient nature of an ephemeral IGP relationship can yield important insights into the underlying causes of invasion failure, including the role of strong biotic resistance.
生物抵抗通常被认为是入侵失败的原因，但很少被了解。竞争和捕食是最常被识别的可能阻止或限制非本地物种建立的过程。非本地和本地物种之间涉及种内捕食（IGP）的相互作用在自然界中非常普遍，尽管理论预测大多数 IGP 系统应该不稳定并导致灭绝。如果这一预测是正确的，由于其短暂的性质，由于 IGP 导致的入侵失败的频率可能被低估了，因此，尽管它们提供了理解影响其不稳定动态的因素的机会，但对不稳定的 IGP 系统的研究仍然缺乏。我们调查了一个涉及 IGP 关系的入侵失败案例。在佛罗里达州，全球入侵物种孔雀鱼（Poecilia reticulata）在东部食蚊鱼（Gambusia holbrooki）存在的情况下无法建立。我们通过重复的中观和水族馆试验测试了本地食蚊鱼是否以及如何导致孔雀鱼入侵失败。IGP 关系的捕食者和竞争者两个组成部分都具有很强的不对称性，对孔雀鱼产生了巨大的影响。我们确定了两种影响，即对幼鱼的直接捕食和攻击性干扰竞争，这限制了它们的生存和繁殖。这种 IGP 关系的高度不稳定性质是孔雀鱼在佛罗里达州无法建立的主要原因。我们的研究表明，短暂的 IGP 关系的短暂性质可以为入侵失败的根本原因提供重要的见解，包括强大的生物抵抗的作用。
