Mapping the trophic ecology of the invasive American blue crab Callinectes sapidus: a global scoping review across native and invaded ecosystems

Biological invasions by predatory species are major drivers of biodiversity loss and food-web reorganization, particularly in coastal ecosystems. The American blue crab Callinectes sapidus , native to the western Atlantic, has expanded worldwide and is now established in European and Mediterranean systems. While its trophic ecology is well documented in its native range, evidence from invaded ecosystems remains fragmented and geographically biased. Here, we present a scoping review of the trophic ecology of C. sapidus across native and invaded ranges to assess trophic roles, identify knowledge gaps, and derive management insights. Following PRISMA-ScR guidelines, we screened the literature up to December 2025 and retained 285 studies addressing diet, predation, trophic position, and food-web interactions. Research effort is overwhelmingly concentrated in the native range, whereas studies in invasive systems have emerged only since 2013 and remain limited in number and coverage. Methodological approaches have progressively shifted from single dietary assessments toward integrative frameworks combining feeding trials, field observations, gut or stomach content analyses, and stable isotope techniques. Across native and invaded ranges, C. sapidus is consistently described as an opportunistic generalist predator with broad trophic plasticity. Our synthesis identifies benthic invertebrates as the most vulnerable trophic compartment, particularly bivalves and other weakly mobile taxa. Predation patterns are largely structured by functional prey traits such as size, mobility, burrowing ability, and shell strength. By identifying vulnerable trophic compartments and major knowledge gaps, this review provides a framework for monitoring and management of blue crab invasions, particularly in Mediterranean ecosystems where evidence remains limited.