Effects of practical diets with different levels of protein on the survival and growth of the pink shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967)
The present study aimed to evaluate the survival and growth of the pink shrimp Farfantepenaeus paulensis (Peréz-Farfante, 1967) fed with practical diets containing different protein levels. Juveniles with an initial average weight (± SD) of 0.23g (± 0.08) were grown for 28 days in a marine water recirculation system with 24 tanks containing 40 liters. Each experimental unit was populated with 30 individuals. The experimental design was completely randomized with six treatments (diets with 25, 30, 35, 40, 45 and 50% crude protein) and four replications. The data were treated with univariate analysis of variance (ANOVA) and the Duncan test, and the differences were considered significant at the 5% level. The results indicate that the 40% protein diet resulted in the highest survival rate (average of 93,8%), although this does not differ significantly from diets with 30, 35 and 50% crude protein (survival averages of 91.1, 89.2 and 85.8%, respectively). The survival of treatments with 25, 30, 35, 45 and 50% protein did not differ statistically. Shrimps fed 45% crude protein had the highest average final weight (0.87 g) and weight gain (0.62 g), but there were no significant differences from the 50% protein diet, which, for in turn, it did not differ significantly from treatments with 25, 30, 35 and 40% of crude protein, which presented a final average weight (± SD) of 0.71g (± 0.23), 0.71g (± 0.18) ), 0.76g (± 0.24) and 0.74g (± 0.22), respectively.The results indicate that the prawn juveniles showed better performance when fed with practical diets containing 45% crude protein, this being the maximum recommended level when F. paulensis in the size range between 0.2 and 0.9 g is grown under conditions intensive.