Analyzing fish diets is important for understanding their feeding characteristics and the food webs. Though Carassius auratus and Zacco platypus are dominant fish species in Korea, little research has focused on their feeding ecology. This study investigated the diets of C. auratus, Z. platypus, and Micropterus salmoides, an invasive species, in an urban freshwater ecosystem by analyzing stomach contents using 18S v9 region DNA metabarcoding. Prey community, selectivity,and diversity analyses were performed based on ASV frequencies. Zooplankton was the main prey of Z. platypus collected in August 2020 (69.6%) and C. auratus collected in July 2021 (88.9%). Micropterus salmoides mainly ate fish (85.8%) in August 2020, macroinvertebrates (66.9%) in October 2020, and zooplankton (100%) in July 2021. The selectivity index showed that Z. platypus selectively targets Bacillariophyta, while C. auratus selectively targets Cladocera. Carassius auratus ate a wider variety of prey, and its food diversity was 0.8. The food diversities of Z. platypus and M. salmoides were relatively low, with index values of 0.29 and 0.1, repectively. C. auratus, an omnivorous fish, ate a wide range of plankton, but its trophic level was lower than M. salmoides. Micropterus salmoides mainly fed on fish with lo...