The present study investigated the feeding biology of the minor carp Labeo gonius collected from two different freshwater ecosystem the Burhi Gandak River and Birauli Oxbow Lake in North Bihar, India. From August 2022 to July 2023, a total of 120 specimens were collected by monthly sampling to use gut content analysis, Relative Gut Length (RGL) and Gastro-somatic Index (GaSI) to assess dietary composition, feeding intensity and trophic characteristics. Sand and mud made up the majority of L. gonius diet (48.82% in Burhi Gandak River and 38.14% in Birauli Oxbow Lake), followed by diatoms (18.27% and 22.36%), decayed organic matter (15.96% and 20.95%), green algae (8.81% and 6.50%), macrophytes (5.06% and 9.09%), and blue-green algae (3.06% and 2.83%). The majority of benthic detritus suggests that the species has detritivores bottom-feeding tendencies. GaSI measurements showed seasonal variation in feeding intensity, ranging from 1.5±0.10 to 4.6±0.08 in the Burhi Gandak River and from 1.28±0.07 to 4.89±0.07 in Birauli Oxbow Lake, with greater values in the winter and post-monsoon. An omnivorous to herbivorous feeding behavior was suggested by the RGL values, which varied from 4.7–7.8 in the river and 4.1–6.5 in the oxbow lake. Habitat-based variation in feeding behaviour and food availability is shown by a substantial difference in RGL (P < 0.05) between the two environments. The results show L. gonius ecological adaptability and its critical function in benthic energy transfer in freshwater environments. These findings provide important insights into trophic dynamics and the sustainable management of inland fisheries resources.