The presence of relatively rare species in estuarine fish communities can influence niche differentiation among species, functional redundancy, and ecosystem stability when faced with environmental disturbance. In southeastern Florida, at least four species of snook (Centropomidae) occur in coastal river systems, but only one species occurs elsewhere in the state. To better understand how these species can co-occur, we analyzed data from electrofishing and diet studies conducted during 2007–2010 to investigate niche partitioning between two species: Common Snook Centropomus undecimalis and Smallscale Fat Snook Centropomus parallelus (common and fat snook hereafter). Although the diets of the two species collected from coastal rivers were barely distinguishable, there was separation of habitat use. Adult fat snook had affinities for low salinity portions of rivers, while common snook were distributed more widely. Use of nursery habitat by fat snook occurred during early spring, confirming winter spawning, which contrasts with the protracted spawning of common snook that occurs spring through fall. While in riverine nurseries, juvenile fat snook occupied shallow to moderate depths with cover (e.g., woody debris, docks); common snook had greater affinity for shallow natural shorelines (e.g., mangroves, aquatic macrophytes). Overall, fat snook appeared to occupy niches left open by the generalist common snook. Considering that centropomids are likely to expand their range northward in Florida with climate change, understanding habitat use and niche partitioning among the species may help predict which species is likely to expand first and what habitat types will be occupied.

中文翻译：

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佛罗里达州东南部河流中的斯诺克（双鱼座：Centr科）的生态位划分及其对物种范围限制的影响

当面临环境干扰时，河口鱼类群落中相对稀有物种的存在会影响物种之间的生态位分化，功能冗余和生态系统稳定性。在佛罗里达州的东南部，沿海河系中至少有4种of（Centropomidae）发生，但该州其他地方只有一种。为了更好地了解这些物种可能同时出现，我们分析了从电力捕鱼2007 - 2010年期间进行的调查两个物种之间的利基分区数据和膳食研究：常见斯努克Centropomus undecimalis和小规模脂肪斯努克Centropomus parallelus（此后又常见又胖）。尽管从沿海河流收集到的两种物种的饮食几乎没有区别，但栖息地的使用却是分开的。成年的胖斯诺克对河流的低盐度部分具有亲和力，而普通的斯诺克斯诺克分布更广泛。胖斯诺克利用苗圃栖息地发生在早春，这证实了冬天的产卵，这与春季到秋天发生的普通斯诺克长期产卵形成了鲜明的对比。在河边的苗圃中，少年胖的斯诺克犬占据了浅至中度有盖的深度（例如，木屑，码头）；普通的斯诺克对浅水天然海岸线（例如，红树林，水生植物）的亲和力更大。总体而言，胖斯诺克似乎占据了通才普通斯诺克留下的壁ni。