Crescimento e terminação de tilápia do Nilo, Oreochromis niloticus, na piscicultura Massapê, em Massapê, Ceará

Abstract

Tilapia is the native fish of Africa, Israel and Jordan and due to its potential for aquaculture, had expanded its distribution to all continents in the last fifty years. This study based on the report of supervised intership, in order to monitor and evaluate the performance in the culture of juvenile Nile tilapia, Oreochromis niloticus, Chitralada strain in Fish Massapê in the city of Massapê, Ceará. The final stage was performed in 24 ponds at 25,0 x 135,0 m, giving a total of 3.375 m2. At the bottom of the pond, after to completely empty, agriculture lime was applied at a rate of 1000 kg / ha for the correction of soil pH, after supplying the ponds with water, the fertilization was performed with chicken manure, applying 100 g/m2. For the stocking of juvenile fish the ponds were provided with water at 60-70% of its maximum level. The total number of individuals in each pond was 5.500, forming an initial density of 1,63 individuo/m2, with initial weight ranging between 1g and 60g. After acclimation, fish were fed according to a feeding program that included food rations Guabi with protein levels between 28% and 55% and feeding rates ranging from 2,3% to 10% of the total biomass stored. During the last stage, the water level of ponds was always 100%, with daily replacement of pond with water, to compensate for losses through evaporation and infiltration. Ever that occurred the exageerated production of microalgae, there was drained of pond water, then supply additional. Every two weeks biometric analyzes were made, to evaluate the growth and weight gain of fish. The weight ranged from 400g to 600g fish were harvesting for commercialization. The procedure was done by fishing trawl net. Before the sale, the fish were quickly selected to determine prices. Nonstandard commercial fish had lower sales price. After completion of cultivation in each pond, the total yield was obtained by calculating the number of fish then harvesting, productivity, survival, daily weight gains and weekly weight gains and feed convertion ratio. The cultivation time was 113 days, when the Sector Termination One got the best productivity values. The feed conversion ratio varies between 1.4 and 1.5. The survival average reached was 98%. At the cost of production, the highlight was the food, averaging 60%. The economic indicators of fishfarm Massapê show that it is a profitable activity, as the difference between gross revenues and total costs generated a profit margin of around 26%.The survey of all production costs and the revenue from the sale of production of each pond allowed the determination of the profitability of the production process.