The potential inhibitory effects of the commercial diets on protease activities of Dentex dentex larvae and live foods

Abstract

The aim of this study was to determine the potential inhibitory effects of commercial diets on protease activities of Dentex dentex larvae and live foods. The highest and lowest protease ac-tivity of larvae was 387.08 ±0.23 U/mg protein and 54.66 ±0.15 U/mg protein, respectively. The highest and lowest protease activities of live foods were found in Artemia metanaupli (414.5 ±0.41 U/mg protein) and rotifer (156.25 ±0.09 U/mg protein), respectively. The signifi-cant differences between inhibition amounts of commercial diets on protease activities of lar-vae and live foods were found (p0.05). Also, the significant differences between the inhibi-tion percents were observed (p0.05). The highest inhibition percents of Caviar (200-300μ), Caviar (300-500μ) and copeod were found as 91.86 ±0.26%, 90.72 ±0.13% and 90.82 ±0.22% in enriched rotifers, respectively. In addition, the highest inhibition percents of Caviar (100-200μ) and Proton (200-400μ) were observed as 93.57 ±0.18% and 93.34 ±0.22% in the larvae on day 35, respectively. The effect of Caviar (200-300μ) on protease activities of rotifer was the lowest. In general, copepod had the lower inhibitory effect han those of other com-mercial diets on protease activities of larvae. Copepod showed the lowest effect on protease activity of larvae on day 30. The inhibition percents of commercial diets on protease activities of live foods were high except for rotifers. Our study revealed that the inhibitory effects of commercial diets used through weaning on protease activities of larvae and live foods should be taken into account. In conclusion, the potential inhibitory effects of commercial diets on protease activities of marine fish larvae and live foods to increase the survival and growth rates in hatcheries should be investigated in future studies.