Better together: Cross-tolerance induced by warm acclimation and nitrate exposure improved the aerobic capacity and stress tolerance of common carp Cyprinus carpio

Climate warming is a threat of imminent concern that may exacerbate the impact nitrate pollution on fish fitness. These stressors can individually affect aerobic capacity and stress tolerance fish. In combination, they interact in unexpected ways where exposure to one stressor heighten or reduce resilience another their interactive effects not be uniform across species. Here, we examined how under scenario affects scope (AS), hypoxia heat susceptibility generally tolerant species, common carp Cyprinus carpio. We used 3 × 2 factorial design, were exposed three ecologically relevant levels (0, 50, 200 mg NO - L ?1 ) two temperatures (18 °C 26 °C) for 5 weeks. Warm acclimation increased AS by 11% due maintained standard metabolic rate maximum at higher temperature, improvement seemed greater concentration. Warm-acclimated less susceptible acute hypoxia, acclimated temperature exhibited improved (critical thermal maxima, CTMax) °C. This cross-tolerance attributed hematological results including haemoglobin haematocrit have compensated initial surge methaemoglobin exposure. • Warming are endanger persistence fishes. Interactive warm assessed. carp. Common hypoxia. Warming, pollution, conferred benefits.