Growth, antioxidant capacity and muscle histochemistry of yellowtail kingfish (Seriola lalandi Valenciennes 1883): Selenium and temperature interaction

The aim of this study was to investigate the interactive effects of temperature and dietary selenium concentrations on antioxidant capacity, muscle histochemistry and the growth, of juvenile yellowtail kingfish (Seriola lalandi). The yellowtail kingfish were exposed to two temperatures (21 degrees C or 26 degrees C) and three selenium levels (0.0, 2.0 or 4.0 mg Se kg(-1) of feed) for 30 days. Final weight and specific growth rate (SGR) were significantly affected by water temperature (rho < 0.001) and dietary Se (rho < 0.001) supplementation, and there were significant differences in the interaction between these two factors. Juvenile yellowtail kingfish fed Se-supplemented diets, attained a higher final weight and SGR than those without Se supplementation at 21 degrees C, but not at 26 degrees C. Regardless of the temperature, the red blood cell (RBC) glutathione peroxidase (GPx) activity of yellowtail kingfish fed Se supplemented diets was significantly higher (rho < 0.05) than with the control diet. However, GPx activity of yellowtail kingfish when fed either 2.0 mg Se kg(-1) or 4.0 mg Se kg(-1) showed no significant difference (rho > 0.05). Se concentration in the muscles of juvenile yellowtail kingfish fed Se-supplemented diets was higher than that of the yellowtail kingfish that were fed the control diet. A histopathological test confirmed that 203% of fish muscles exhibited lesions, which occurred in the absence of dietary Se. The outcome of the present study helps in understanding the interactive effects of dietary Se concentrations and the temperature in the farming of yellowtail kingfish. (C) 2016 Elsevier B.V. All rights reserved.