Utilização de diferentes dietas na larvicultura do camarão pitu, Macrobrachium carcinus (Linnaeus, 1758)

Abstract

The freshwater prawn Macrobrachium carcinus production had been commercially explored in several countries. In northeast, the prawn fishery has a great importance in Low São Francisco Basin. The large scale postlarvae production continues being the main problem for commercial culture and natural stocks maintenance. This work aimed to test different diets in Macrobrachium carcinus larval culture in order to improve the performance of prawn post-larvae production, with the utilization of fish flesh (Ff) and a formulated diet (Fd), or in association with adult artemia biomass (FfB and FdB, respectively), resulting in four treatments and six replicates. Were used twenty-four 20 L circular recipients provided of water recirculating and aeration systems, where were stocked 25 larvae (zoea V-VI) per liter. The diets were offered four times a day (07:00, 10:00, 13:00 and 16:00 hrs) during 49 days. Water temperature was 27.5±1.2ºC in the morning and 28.4±1.3ºC in the afternoon; the total ammonia nitrogen and nitrite were 0.2±0.2 and 0.5±0.8 mg/L, respectively, while pH and salinity maintained around 8.2 and 24, respectively. The average larval survival was 3.47±1.56, 7.40±2.99, 14.83±2.64 and 7.57±2.31, respectively for Ff, FfB, Fd and FdB treatments. Ff treatment obtained the lowest survival due to larvae reject by the fish flesh. Fdand FdB treatments showed significant difference (P≤0.05), with better survival obtained by FdB diet. The highest survival was obtained by the Fd diet (14.83%), that showed itself as the more appropriated alternative to use in M. carcinus hatchery, but the adult artemia biomass showed that could provide better survival rates when associated with other feeds.