The combined effects of salinity and temperature on the proximate composition and energetic value of spotted rose snapper Lutjanus guttatus (Steindachner, 1869)

Abstract

Combined effects of temperature (25, 30 and 35°C) and salinity (15, 25, 35 and 45 g L -1 ), on the body composition and energetic value in the juvenile spotted rose snapper ( Lutjanus guttatus ), were investigated over 90 days. Significant effects of temperature, salinity, and their interaction on body composition and energetic value were analyzed. Low temperatures (25°C) significantly reduced the protein and increase lipid content in the body. In a temperature of 30°C, the highest energetic value was recorded, and in the highest salinity (45 g L -1 ), the energetic value was reduced. The salinity of 15 has the highest growth, protein content, and energetic value. It was found that the optimal temperature-salinity combination for the best relationship of growth (3.8% d -1 ), protein (21.9%), and lipid (4.9%) content, and energetic value (2.61 kJ g -1 ) was at 30 to 32.0°C and salinity of 35 g L -1 . The effect of temperature was directly proportional to the increase in protein and inversely with the content of lipids in the body; salinity has its main effect negatively on these parameters in the highest salinity (45 g L -1 ).