Can dietary manipulation mitigate extreme warm stress in fish? The case of European seabass, Dicentrarchus labrax

Abstract Extreme climatic events affect all living organisms, including fish. This study evaluated growth, hematological, immune-antioxidant, and molecular stress responses to understand the acclimatization ability of European seabass, Dicentrarchus labrax fed on four different dietary supplements with subsequent exposure to an extreme ambient warm (32 oC) event. Fish were fed on diets supplemented with vitamins C (0.40%) and E (0.35%), propolis (0.45%), phycocyanin (0.30%), and β-glucan (0.30%) along with a control diet for 56 days, followed by 18 days of extreme warm exposure. Fish growth performance and survival were higher in fish fed on propolis followed by vitamins C & E and phycocyanin supplemented diets compared to fish fed on the control diet. During extreme warm exposure, red blood cells (RBC), hematocrit, hemoglobin, respiratory burst (RB), serum lysozyme activities (LSZ), and insulin-like growth factor 1 (Igf1) were significantly (P