Fruit preferences by fishes in a Neotropical floodplain

The diets of frugivorous animals result from the interaction between feeding preference and ecological factors such as availability of alternative resources and interactions with other frugivores. A better understanding of frugivore diets will enable predictions about the vulnerability of plant populations to anthropogenic or natural environmental changes. In addition, frugivores with greater variation in diet (generalists) are potentially more resilient to habitat changes than specialists. Here, we combined data on diets of frugivorous fishes with visual censuses on fruit availability to evaluate if fishes are selective or opportunistic in their use of fruits in floodplain habitats. We found a high diversity of fruit species (74 species) frequently consumed by four common species of frugivorous fishes during the flooding season. The identity of preferred fruits, rather than their availability, had a stronger effect on the patterns of fruit consumed by fishes in this system. Fruit preferences by fish may influence the long-term persistence and the maintenance of plant diversity in floodplain habitats. Possible disturbances of fish populations with selective consumption and the plant populations on which they depend could increase the vulnerability of both populations involved. Thus, selectivity may affect ecological and evolutionary processes associated with frugivory by fish.食果动物（frugivorous animals）的食谱由取食偏好与生态因子共同塑造，这些生态因子包括替代食物资源的可获得性，以及与其他食果动物的种间互动。对食果动物食谱的深入解析，有助于预测植物种群对人为或自然环境变化的脆弱性。此外，食谱变异度更高的食果动物（广食性物种）相较专食性物种，对生境变化的耐受能力更强。本研究将食果鱼类（frugivorous fishes）的食谱数据与果实可获得性的目视普查数据相结合，旨在评估泛滥平原生境中鱼类对果实的利用是选择性的还是机会主义的。研究发现，在洪水季，4种常见食果鱼类会频繁取食多达74种果实类物种，果实物种多样性极高。在该研究系统中，鱼类偏好的果实种类而非其可获得性，对鱼类取食的果实模式具有更强的调控作用。鱼类的果实取食偏好，可能会影响泛滥平原生境中植物多样性的长期维持与种群存续。对具有选择性取食习性的鱼类种群及其依赖的植物种群的潜在干扰，可能会提升二者的脆弱性。因此，鱼类的取食选择性可能会影响与鱼类食果行为（frugivory）相关的生态与进化过程。