Asynchronous trophic niche shifts among invertebrate-feeding fishes across a coral cover gradient
Year: 2026
Type: preprint
Abstract: A bstract Unraveling the links between habitat structure, resource availability and the trophic niche is key to anticipate the effects of global change on ecosystems. On coral reefs, recurrent coral bleaching and increasing anthropogenic pressures have led to rapid losses of structural complexity, with implications for food web dynamics. Invertivorous fishes represent a diverse trophic guild whose dietary niches may be particularly sensitive to variation in benthic habitat composition. Yet, whether species within this guild exhibit similar patterns of trophic niche differentiation across contrasting reef states remains poorly understood. Here, we combine otolithometry, gut content metabarcoding, and stable isotope analysis to investigate growth performance and interspecific variation in trophic niche structure among six invertivorous fish species across contrasting coral cover conditions in French Polynesia. Species exhibited differences in trophic niche breadth between high- and low-coral-cover sites, but the direction and magnitude of these differences varied among species. Despite these differences, interspecific trophic niche overlap remained largely unchanged across coral cover conditions. Rather than exhibiting synchronous trophic patterns, species within the same guild displayed contrasting niche variations across reef conditions, without consistent changes in interspecific niche overlap. These findings challenge the assumption that species sharing a trophic guild respond uniformly to habitat variation and highlight the importance of accounting for interspecific differences in trophic niches when predicting how changes in habitat structure may reorganize food webs.
Institutions: École Pratique des Hautes Études, Université Paris Sciences et Lettres, Centre de Recherches Insulaires et Observatoire de l'Environnement, Ifremer, Institut de Recherche pour le Développement, University of French Polynesia, Centre National de la Recherche Scientifique, Station d’Écologie Théorique et Expérimentale, Smithsonian Institution, National Museum of Natural History, University of Texas at Austin Marine Science Institute, The University of Texas at Austin
Language: English
Subfield: Ecology
Field: Environmental Science
Domain: Physical Sciences
SDG: Life below water
Open Access status: green
OpenAlex ID: W7222657970