UMR IMEP-CNRS 6116, université de Provence, case 36, 3, place Victor-Hugo, 13331 Marseille cedex 3, France.
C R Biol. 2010 Aug;333(8):613-21. doi: 10.1016/j.crvi.2010.05.002. Epub 2010 Jul 1.
This study aimed at examining resource partitioning both at the inter- and intraspecific levels between paired chondrostome fishes: Chondrostoma nasus, the nase, C. toxostoma, the sofie, and their hybrid. The study was performed in the south of France and concerned a main river (the Durance River) and a tributary (the Buech River). In these rivers, C. nasus was an introduced species, originating in central Europe, and C. toxostoma was an endemic congener, in the south of France. Stable isotope analysis was used to analyse trophic and spatial niches. Isotopic differences indicated that individuals from the three taxa (C. nasus, C. toxostoma and their hybrid) have different spatial origins. At the interspecific level, the different chondrostomes originating from the Buech River showed a high level of trophic niche overlap. At the intraspecific level, nase individuals originating from the different spatial origins showed a resource polymorphism; differences in morphology were associated with variation in behaviour and life history traits. Their coexistence was a likely outcome of resource polymorphism. This study provides an example of the importance of considering the link between intra- and interspecific interactions to gain an understanding of the mechanisms driving the coexistence of species-pairs.
本研究旨在检验配对软骨鱼类（欧鳊、索非鲫及其杂交种）的种间和种内资源分区。该研究在法国南部的一条主河（德龙河）和一条支流（比埃什河）进行。在这些河流中，欧鳊是一种来自中欧的引入种，索非鲫则是法国南部的特有种。稳定同位素分析用于分析营养和空间生态位。同位素差异表明，来自三个类群（欧鳊、索非鲫及其杂交种）的个体具有不同的空间起源。在种间水平上，来自比埃什河的不同软骨鱼类表现出高度的营养生态位重叠。在种内水平上，来自不同空间起源的欧鳊个体表现出资源多态性；形态差异与行为和生活史特征的变化相关。它们的共存可能是资源多态性的结果。本研究提供了一个例子，说明了考虑种内和种间相互作用之间的联系对于理解驱动物种对共存的机制的重要性。
