Xiao Qiao-Zhi, Chen Li-Juan, Jin Jin-Jin, Qiu Yu-Ping, Chen Guo-Zhu
National Wetland Ecosystem Fixed Research Station of Danchi, Southwest Forestry University, Kunming 650224, China.
College of Wetlands/National Plateau Wetland Research Center, Southwest Forestry University, Kunming 650224, China.
Ying Yong Sheng Tai Xue Bao. 2020 Jun;31(6):2087-2097. doi: 10.13287/j.1001-9332.202006.040.
The theory of ecomorphology predicts that species with similar morphological traits can occupy similar ecological niche, which may cause competitive exclusion. To apply this theory into fish invasion ecology research is of significance for understanding the interaction between native and invasive species. Here, we compared the morphological difference between two native (Oryzias pectoralis, Oryzias curvinotus) and one invasive species (Gambusia affinis) to explore the competitive exclusion among them. The results showed that despite O. pectoralis and O. curvinotus were sympa-tric species, they varied in spatial distribution. Such a result supported the theory of ecomorphology, which predicts that two species with similar morphological traits might have strong competition. Moreover, their population density exhibited a significant negative relationship with that of G. affinis. The morphology of G. affinis and both Oryzias species were more similar when comparing to other fish in the assemblage. Results from the cluster analysis showed that G. affinis and Oryzias species were close in a branch, with extremely low spatial niche overlap between invasive mosquitofish and native Oryzias species. There was significant negative correlation between the population abundance of mosquitofish and Oryzias species. All the results suggested that mosquitofish led to population decline of both Oryzias species, due to the ecomorphological similarity. More studies are needed to better understand the mechanisms of G. affinis invasion in habitats of native Oryzias species.
生态形态学理论预测，具有相似形态特征的物种可能占据相似的生态位，这可能导致竞争排斥。将这一理论应用于鱼类入侵生态学研究，对于理解本地物种与入侵物种之间的相互作用具有重要意义。在此，我们比较了两种本地物种（胸鳍青鳉、弓背青鳉）和一种入侵物种（食蚊鱼）之间的形态差异，以探究它们之间的竞争排斥情况。结果表明，尽管胸鳍青鳉和弓背青鳉是同域物种，但它们在空间分布上存在差异。这一结果支持了生态形态学理论，该理论预测，具有相似形态特征的两个物种可能存在激烈竞争。此外，它们的种群密度与食蚊鱼的种群密度呈现出显著的负相关关系。与组合中的其他鱼类相比，食蚊鱼与两种青鳉属鱼类的形态更为相似。聚类分析结果表明，食蚊鱼和青鳉属鱼类在一个分支中距离较近，入侵的食蚊鱼与本地青鳉属物种之间的空间生态位重叠极低。食蚊鱼的种群丰度与青鳉属物种之间存在显著的负相关。所有结果表明，由于生态形态学上的相似性，食蚊鱼导致了两种青鳉属鱼类的种群数量下降。需要更多的研究来更好地理解食蚊鱼入侵本地青鳉属物种栖息地的机制。
