Feeding strategies and diet variation in livebearing fishes of the genusLimia(Cyprinodontiformes: Poeciliidae) in the Greater Antilles

Abstract

AbstractFeeding specialisations are known to play an important role in the ecology and evolution of many organisms. In this study, we performed a comparative analysis based on the data of the gut content of eight species of the genusLimia(family Poeciliidae) to explore the potential role of feeding ecology in the radiation of this genus in the Caribbean. We analysed the feeding strategies using the modified Costello's graphical method. In addition, we estimated the contribution of each food item to the diet by calculating the alimentary index of six different functional categories that summarised the variation in main type of consumed items. We also compared the niche breadth for all analysed species and the niche breadth variation between wet and dry seasons in four species we were able to sample in both periods of the year. Most of the analysed species showed preference for detritus and algae. Species that exhibited a more omnivorous diet such asL. versicolorandL. perugiaerevealed moderate levels of consumption of terrestrial and aquatic invertebrates. Nonetheless, some species such asL. yaguajaliandL. nigrofasciatashowed specialisations towards detritus as the dominant food item found in the gut content analysis. In general, niche breadth values were higher in the wet season than in the dry period. Our study showed that the majority of species analysed tend to be feeding generalists, but some degree of specialisation occurs in some species from Hispaniola where the diversity of the genusLimiais remarkably higher compared to the rest of the Greater Antilles.