Department of Biology, Saint Martin's University, Lacey, WA, USA.
Department of Wildlife, Fish, and Conservation Biology, University of California, Davis, CA, United States of America.
PeerJ. 2024 May 10;12:e17307. doi: 10.7717/peerj.17307. eCollection 2024.
Invasive species threaten biodiversity globally. Amphibians are one of the most threatened vertebrate taxa and are particularly sensitive to invasive species, including other amphibians. African clawed frogs () are native to Southern Africa but have subsequently become invasive on multiple continents-including multiple parts of North America-due to releases from the pet and biomedical trades. Despite their prevalence as a global invader, the impact of remains understudied. This includes the Pacific Northwest of the USA, which now hosts multiple expanding populations. For many amphibians, chemical cues communicate important information, including the presence of predators. Here, we tested the role chemical cues may play in mediating interactions between feral and native amphibians in the Pacific Northwest. We tested whether native red-legged frog () tadpoles display an antipredator response to non-native frog () or native newt (rough-skinned newts, ) predator chemical stimuli. We found that tadpoles exhibited pronounced anti-predator responses when exposed to chemical cues from but did not display anti-predator response to invasive chemical cues. We also began experimentally testing whether -which produce a powerful neurotoxin tetrodotoxin (TTX)-may elicit an anti-predator response in , that could serve to deter co-occupation. However, our short-duration experiments found that were attracted to newt chemical stimuli rather than deterred. Our findings show that likely poses a threat to native amphibians, and that these native species may also be particularly vulnerable to this invasive predator, compared to native predators, because toxic native newts may not limit invasions. Our research provides some of the first indications that native Pacific Northwest species may be threatened by feral and provides a foundation for future experiments testing potential management techniques for .
入侵物种对全球生物多样性构成威胁。两栖动物是受威胁最严重的脊椎动物类群之一，特别容易受到入侵物种的影响，包括其他两栖动物。非洲爪蟾原产于南非，但由于宠物和生物医学贸易的释放，随后在包括北美洲多个地区在内的多个大陆上成为入侵物种。尽管它们是全球入侵物种的代表，但对 的影响仍研究不足。这包括美国西北部，现在有多个不断扩大的 种群。对于许多两栖动物来说，化学信号传递着重要的信息，包括捕食者的存在。在这里，我们测试了化学信号在调解太平洋西北地区野生 和本地两栖动物之间相互作用中可能发挥的作用。我们测试了本地红腿蛙蝌蚪是否会对非本地青蛙或本地蝾螈（粗糙皮肤蝾螈）的捕食者化学刺激做出抗捕食者反应。我们发现， 蝌蚪在暴露于 化学线索时表现出明显的抗捕食者反应，但对入侵 的化学线索没有表现出抗捕食者反应。我们还开始实验测试 - 产生一种强大的神经毒素河豚毒素（TTX） - 是否会在 中引起抗捕食者反应，这可能有助于阻止共同占领。然而，我们的短期实验发现， 被蝾螈的化学刺激所吸引，而不是被阻止。我们的研究结果表明， 可能对本地两栖动物构成威胁，与本地捕食者相比，这些本地物种可能对这种入侵捕食者特别脆弱，因为有毒的本地蝾螈可能不会限制 的入侵。我们的研究提供了一些初步迹象，表明本地太平洋西北地区物种可能受到野生 的威胁，并为未来测试针对 的潜在管理技术的实验提供了基础。
