Sánchez-Hernández Javier, Fernández de Larrea Iñaki, de Guzmán Ioar, González José M, Larrañaga Aitor
Área de Biodiversidad y Conservación, Departamento de Biología y Geología, Física y Química Inorgánica, Universidad Rey Juan Carlos (URJC), Madrid, Spain.
Instituto de Investigación en Cambio Global (IICG), Universidad Rey Juan Carlos, Móstoles, Madrid, Spain.
J Fish Biol. 2025 Oct;107(4):1420-1432. doi: 10.1111/jfb.70136. Epub 2025 Jul 13.
The trophic ecology of animals often results from complex interactions between environmental and biological drivers. Yet, studies that explore trophic ecology across multiple fish species while considering a wide range of environmental variables remain limited. In this study, we analysed diet and niche variation in fish communities across five protected areas in the northern Iberian Peninsula, examining their responses along environmental and biological gradients. Our multiple regression analyses showed that both environmental and biological drivers significantly influence fish feeding behaviour and individual specialisation, but these effects are species-specific. We propose that the primary mechanisms shaping fish feeding strategies, whether benthic foraging or surface-drift feeding, are determined by intrinsic factors such as species-specific feeding behaviours and ontogenetic stage, along with benthic macroinvertebrate density and fish density. Specifically, benthic macroinvertebrate density positively affected individual niche specialisation in brown trout (Salmo trutta) and Pyrenean stone loach (Barbatula quignardi), whereas it negatively impacted the Pyrenean minnow (Phoxinus bigerri). An increase in total fish density, measured as the number of fish per square meter, negatively influenced individual niche specialisation of brown trout. However, brown trout density had a positive effect on individual niche specialisation of Pyrenean stone loach and Pyrenean minnow. The findings have direct implications for conservation and restoration efforts, highlighting the importance of increasing habitat heterogeneity to meet species-specific habitat needs and promoting benthic macroinvertebrate production to support fish feeding requirements.
动物的营养生态学往往源于环境驱动因素和生物驱动因素之间的复杂相互作用。然而，在考虑广泛环境变量的同时，对多种鱼类的营养生态学进行探索的研究仍然有限。在本研究中，我们分析了伊比利亚半岛北部五个保护区鱼类群落的食性和生态位变化，研究它们在环境和生物梯度上的响应。我们的多元回归分析表明，环境驱动因素和生物驱动因素都对鱼类的摄食行为和个体特化有显著影响，但这些影响具有物种特异性。我们提出，塑造鱼类摄食策略（无论是底栖觅食还是表层漂流摄食）的主要机制是由内在因素决定的，如物种特异性摄食行为和个体发育阶段，以及底栖大型无脊椎动物密度和鱼类密度。具体而言，底栖大型无脊椎动物密度对褐鳟（Salmo trutta）和比利牛斯石鳅（Barbatula quignardi）的个体生态位特化有正向影响，而对比利牛斯米诺鱼（Phoxinus bigerri）有负面影响。以每平方米鱼类数量衡量的总鱼类密度增加，对褐鳟的个体生态位特化有负面影响。然而，褐鳟密度对比利牛斯石鳅和比利牛斯米诺鱼的个体生态位特化有正向影响。这些发现对保护和恢复工作有直接影响，强调了增加栖息地异质性以满足物种特定栖息地需求以及促进底栖大型无脊椎动物产量以支持鱼类摄食需求的重要性。
