Effect of temperature and diet on growth and gastric emptying time of the hybrid, Epinephelus fuscoguttatus ♀ × E. lanceolatus ♂

Abstract

The effects of temperatures (22, 26, 30 and 34 °C) and diets (commercial pellet and shrimp) on the growth properties and gastric emptying time (GET) of the tiger grouper × giant grouper (TGGG) hybrid were analyzed over a 30 day experimental period under controlled laboratory conditions. Food consumption (FC), food conversion rate (FCR), specific growth rate (SGR) and GET were significantly influenced by temperature and diet type. The highest mean SGR (1.00% BM day−1, p < 0.05) was observed in the 30 °C + shrimp group of fish, while the lowest SGR was observed in the 22 °C + pellet group (0.59% BM day−1). No significant differences in growth (P > 0.05) were observed between any of the groups at 22 and 34 °C fed on either the shrimp or the pellet diet. The lowest statistically significant (p < 0.05) FC was observed at 22 °C on both diets. The highest FCR (1.208, p < 0.05) was observed in the 22 °C + shrimp and 22 °C + pellet groups. The fastest GETs were observed at 30 °C, 12 h for fish on the shrimp diet and 13 h for fish on the pellet diet. A significant delay in gastric emptying (16 h) was observed at 22 °C in the group fed the commercial pellet diet (16 h). The best growth performances and digestion rates were observed at 30 °C followed by 26, 34 and 22 °C regardless of diet. The results suggest that 26 and 30 °C are optimum water temperatures for the aquaculture of this newly developed fish species fed on either a shrimp or pellet diet.