Effects of temperature and diet on pepsin enzyme activity of TGGG hybrid grouper, Epinephelus fuscoguttatus ♀ x E. lanceolatus ♂

Abstract

Aim: This study explores the influence of temperature and diet on pepsin enzyme activity in TGGG hybrid groupers. Methodology: Two hundred TGGG groupers (body weight 200±10 g; total length 22.5±1 cm) were equally distributed in three rearing tanks (1500 l capacity). After three weeks of acclimatization, the groupers were kept in 40 tanks (5 fish per tank, 20 tanks with pelleted diet and 20 with shrimp diets) for 30 days. All treatments were replicated five times. Results: Pepsin activity increased with increased temperature, from 22°C (2.10 U mg protein−1) to 30°C (5.64 U mg protein−1) when the groupers were given either pellet or shrimp as diet. The shrimp-fed group showed significantly increased pepsin activity compared to pellet-fed fish. Interpretation: The pepsin enzyme activities in TGGG hybrid groupers were significantly influenced by temperature and diet, but the interaction of these two factors was insignificant. The results suggest that shrimp-diets given at 30°C water was ideal for rearing TGGG hybrid groupers. This suggests that combination proliferates enzymatic activity, which may lead to faster digestion and faster growth rates compared to other combinations.