The diploid distant hybrid (2nBY) derived from female blunt snout bream (Megalobrama amblycephal, BSB) × male Bleeker’s yellow tail (Xenocypris davidi Bleeker, YT). To investigate the hypoxia tolerance and the regulatory mechanisms of hypoxia-inducible factor-1α/2α (hif-1α/2α) in 2nBY, BSB, and YT, experiments consisting of 24 h of hypoxia treatment (DO = 2.0 ± 0.1 mg/L) followed by 6 h of reoxygenation were conducted. The los...