Rettig Jessica E, Tristano Elizabeth P, Burger Anthony C, Smith Geoffrey R
Department of Biology Denison University Granville Ohio USA.
Ecol Evol. 2024 Oct 30;14(11):e70508. doi: 10.1002/ece3.70508. eCollection 2024 Nov.
Aquatic ecosystems are often negatively affected by invasive species. However, biotic resistance by native species, either by competition or predation, can reduce the impacts of invasions by non-native species. The Western Mosquitofish () is one of the most impactful invasive species of freshwater fish and cause declines in native fish populations. Using two mesocosm experiments conducted in different years, we examined the ecological interactions between juveniles of the native fish, Bluegill Sunfish (), and adults of the invasive fish, . We found evidence for interactions between and . However, interactions did not appear symmetric, with generally more affected by intraspecific interactions than interspecific interactions whereas was more affected by interspecific interactions than intraspecific interactions. The presence of either species of fish led to a decrease in the number of large zooplankton and a tendency for a decrease in the total number of zooplankton. Based on these results, native appear to be able to reduce the ability of non-native to establish or maintain populations through both competition and predation (i.e., acting as an intraguild predator). The consistency of our results across both experiments, with their different designs and their occurring in different years, gives weight to these conclusions. The reduction of or prevention of establishment of populations of invasive would likely benefit the aquatic communities of ponds with fish, especially small-bodied native fish.
水生生态系统常常受到入侵物种的负面影响。然而，本地物种通过竞争或捕食产生的生物抗性，可以降低非本地物种入侵所带来的影响。西部食蚊鱼（）是最具影响力的淡水鱼入侵物种之一，会导致本地鱼类种群数量下降。通过在不同年份进行的两项中型生态系统实验，我们研究了本地鱼类蓝鳃太阳鱼（）的幼鱼与入侵鱼类的成鱼之间的生态相互作用。我们发现了 与 之间存在相互作用的证据。然而，这种相互作用似乎并不对称， 通常受种内相互作用的影响比种间相互作用更大，而 受种间相互作用的影响比种内相互作用更大。两种鱼类中任何一种的存在都会导致大型浮游动物数量减少，并且浮游动物总数有减少的趋势。基于这些结果，本地的 似乎能够通过竞争和捕食（即作为集团内捕食者）来降低非本地的 建立或维持种群的能力。我们在两项设计不同且年份不同的实验中都得到了一致的结果，这使这些结论更具说服力。减少或防止入侵的 种群的建立可能会使有鱼的池塘的水生群落受益，尤其是小型本地鱼类。
