Trophic traits and phylogenetic relatedness in tropical carnivorous fish assemblages

Ecological similarities among species often stem from their shared evolutionary history, as evidenced by the phylogenetic signal. This signal indicates that closely related species tend to exhibit greater similarity in ecological traits compared to unrelated species. From a trophic niche perspective, this relationship remains unclear. We aim to assess the extent to which the trophic niche in tropical carnivorous fish community is shaped by evolutionary phylogenetic signal. The data were collected in a tropical coastal ecosystem. We operationalized the trophic niche by incorporating diet, feeding habits, and foraging patterns, using metrics such as trophic niche breadth, trophic level, and individual diet specialization. A total of 38 tropical fish species were studied, with consistent species composition across seasons. Dietary variability and density were higher in the wet season. A phylogenetic signal was observed for maximum length and individual diet specialization, but not for trophic niche breadth or level. The strong phylogenetic signal for maximum length and individual diet specialization suggests that evolutionary relationships significantly shape these traits, reflecting the influence of body size and dietary preferences on ecological interactions. The high variability in niche breadth among species suggests that resource availability and ecological factors significantly influence this trait, beyond phylogenetic constraints. Migratory predators, primarily high-trophic-level species, play a key role in promoting niche differentiation, supporting ecosystem resilience, and sustaining high biodiversity through their influence on trophic dynamics. Our findings reveal complex phylogenetic interactions among the trophic traits of tropical fish indicating that factors beyond evolutionary relationships significantly influence these traits.