Nonnative African jewelfish are more fit but not bolder at the invasion front: a trait comparison across an Everglades range expansion
Nonnative African jewelfish are more fit but not bolder at the invasion front: a trait comparison across an Everglades range expansion
复制标题
非本地非洲宝石鱼在入侵前线更健康，但并不更大胆：大沼泽地范围扩展的特征比较
作者：
D. P. López;A. A. Jungman;J. Rehage
入侵物种对自然生态系统和本地生物多样性构成全球性威胁。此前的研究表明，入侵范围的扩大往往与入侵者的生活史和扩散行为有关。在行为特征中，大胆是一个关键特征，可以帮助物种在新环境中表现良好。因此，在一个物种的入侵范围内，来自入侵前线的个体应该更大胆，更好的分散能力，并且具有相对于现有种群最大程度地实现种群增长的生活史。我们通过大沼泽国家公园 (ENP) 的非洲宝石鱼 Hemichromis letourneuxi 的入侵来检验这些假设。宝石鱼于 2000 年进入 ENP，此后它们的范围迅速但可追踪地扩大。我们的研究检查了六个野生捕获的非洲宝石鱼种群的生殖投入、身体状况、肠道饱满度、胆量和扩散行为的变化。在大型户外实验装置中使用羽化活动测试和羽化扩散测试来测试大胆性和扩散性。我们解剖了六个种群的鱼以评估生活史。来自入侵前线（西部 ENP）的种群具有更高的繁殖投入、更高的肠道饱满度和更好的身体状况，但他们并不比内部种群（东部 ENP）相对更大胆，也不是更好的分散者。随着入侵的进展，入侵前沿较低的种内密度可能会放松竞争，并允许更高的适应性和繁殖投资。了解入侵的潜在行为和生活史机制是制定旨在遏制当前入侵者并防止未来入侵者扩散的管理策略的关键。
Invasive species present a global threat to natural ecosystems and native biodiversity. Previous studies have shown that invasive range expansion is often related to the invader’s life histories and dispersal behavior. Among behavioral traits, boldness is a key trait that may aid species in performing well in novel environments. Thus, along a species’ invaded range, individuals from the invasion front should be bolder, better dispersers, and have life histories that maximize population growth relative to established populations. We tested these hypotheses with the invasion of the African jewelfish Hemichromis letourneuxi in Everglades National Park (ENP). Jewelfish entered ENP in 2000, and since then they have expanded their range rapidly but traceably. Our study examined variation in reproductive investment, body condition, gut fullness, boldness, and dispersal behavior across six wild-caught populations of African jewelfish. Boldness and dispersal were tested using an emergence-activity test and an emergence-dispersal test in large, outdoor experimental setups. We dissected fish from the six populations to assess life histories. Populations from the invasion front (western ENP) had higher reproductive investment, higher gut fullness, and better body condition, but they were not relatively bolder nor better dispersers than inner populations (eastern ENP). As the invasion progressed, lower intraspecific density at the invasion front may have relaxed competition and allowed for higher fitness and reproductive investment. Understanding underlying behavioral and life-history mechanisms of an invasion is key for the development of management strategies that aim to contain current invaders and prevent the spread of future ones.
影响因子：
8.8
作者：
Burton, Olivia J.;Phillips, Ben L.;Travis, Justin M. J.
通讯作者：
Travis, Justin M. J.