Temperature‐driven diet shift in an invasive omnivorous crustacean feeding on plankton

Abstract

Global warming alters the physiology of ectotherm consumers, potentially making their diets more herbivorous. However, the relevance and generality of these changes remain poorly understood in a multispecies context. To address this critical knowledge gap, we experimentally tested the temperature‐dependent feeding preference of the invasive mysid Limnomysis benedeni on different combinations of autotrophic (phytoplankton) and heterotrophic (zooplankton) prey species varying in body size. Warming increased the ratio of autotrophic‐to‐heterotrophic prey consumption across all treatments, driven by reduced heterotrophic prey consumption and, where larger zooplankton ( Brachionus calyciflorus and Daphnia magna ) were present, an additional increase in phytoplankton ingestion. Total carbon ingestion did not increase consistently with warming, indicating diet reallocation instead of increased overall feeding intensity at higher temperatures. These findings suggest that warming can change the trophic role of invasive consumers, potentially modulating their effects on community dynamics, and provide a basis for future research in more realistic ecological settings.