A very picky eater: Species-level prey selection in the endangered Rhone streber [Zingel asper (L. 1758)]

Prey preferences are important drivers of predator-prey interactions and trophic network structure. We present a species-level selection analysis for the endangered Zingel asper (L. 1758) and its prey within the Baetis (Ephemeroptera) genus. By combining robust diet metabarcoding data with fine-scale prey community data, we revealed that Z. asper selected four Baetis species differently, despite being largely considered as ecologically similar species. Our results suggest that fine-resolution analysis of prey selection may be key for understanding trophic interactions and for improving the conservation and management of fish.