de Souza Sampaio, C.M., Valenti, W.C., Carneiro, D.C.
Abstract:
Some essential aspects of M. rosenbergii feed are unknown and it constitutes a cornerstone in prawn culture. The aim of this study was to evaluate the effects of feeding rates and feeding frequency on the performance of M. rosenbergii postlarvae.
A 5x5 factorial experiment with three temporal replicates per treatment was designed. Five daily feed application rates (30%, 60%, 90%, 120% and 150%), as a percentage of prawn body weights, and five different frequencies (1, 2, 4, 6 and 8 times daily) were used. Postlarvae (11 mg) were grown in 90 L asbestos tanks for 20 days at a density of 50 m2 (1/L) at water temperature of 28.0 +/- 0.1 C. Prawns fed on a dry, formulated fed (40.86% crude protein). Dissolved oxygen, pH and amount of ammonium were monitored and remained within the adequate level for right development of M. rosenbergii. Growth, survival and condition factor were evaluated and data were analyzed with a one-way ANOVA.
A significant effect of feeding rate was observed only on survival; mean survival range from 50.3% to 65.3% and were significantly lower (P<0.05) when the postlarvae were fed 30% of body weight. Feed applications higher than 60% did not result in increased survival. Feed frequency did not exert effects on growth, survival and condition factor (P>0.05) and interactions was not significant (P>0.05).
Certainly, postlarvae did not eat 60% of body weight daily; however, they are very small and the amount of feed must be enough to all prawns to find food in the tank. Results of this experiment indicate that postlarvae reared in indoor tanks should be fed once a day at about 60% of body weight. The feeding schedule should be practical for commercial indoor nursery culture, generally the first phase of nursery.
(Centro de Aquicultura da Universidade Estadual Paulista (CAUNESP). Nucleo de Estudos em Biologia, Ecologia e Cultivo de Crustaceos (NEBECC), Rodovia Carlos Tonanni Km 5 - 14.870-000 Jaboticabal, Sao Paulo, Brazil)
***************