Effects of dietary taurine levels on epidermal thickness and scale loss in red sea bream, Pagrus major

Taurine is often added to artificial fish diets to compensate for a reduction in fish meal (FM). However, the taurine content of FM-based diets is typically lower than in diets consisting of raw fish, even in diets where FM is the only protein source. We evaluated the effects of dietary taurine in FM-based diets on epidermal thickness and scale detachability in red sea bream Pagrus major. We compared the effect of diets containing 0% (control), 0.3% (Tau-0.3%), 0.6% (Tau-0.6%) and 1.0% (Tau-1.0%) taurine. Red sea bream (average body weight, 39 g) were fed these diets for 7 weeks. Taurine supplementation had no effect on growth, feed intake, feeding efficiency, or survival. However, the epidermal thickness was higher in fish in the Tau-0.6% and Tau-1.0% groups than in the control and Tau-0.3% groups. Similarly, scale loss was significantly higher in the control group than in the Tau-0.6% and Tau-1.0% groups. Our results suggest that supplementation with > 0.6% taurine (1.0% in diet) improves skin condition.