Densidade de estocagem de piracanjuba (Brycon orbigniannus) em tanques-rede de pequeno volume

Abstract

The density of stocking (DS) is a factor that can affect the development of fish. The aim of this current study was to analyze the effect of DS over the survival, weight, growth, and biomass hematology and chemical composition of juveniles Brycon orbignyannus farmed in cages. The experiment was realized in the area of transition of the tank of Itaipu Binational in the center of research development to fish farm in cages located in the Biological Refuge in the city of Santa Helena-PR, for a period of five months. It was used 750 juveniles with an initial average weight and length of 26.72+-5,99 g and 13.45+-0,99cm, respectively distributed in twelve cages of 1,00m3 randomly in a design completely casualized and three repetitions. The animals received commercial food extruded containing 36% of rough protein and they were feed three times a day until the visible satiety. At the end of the experimental period, the fish were kept in fasting for a period of 24 hours. Subsequently, they were realized the proceeding of blood collection assessment of the parameters of performance, income and chemical composition of the animals carcass. The survival and the final biomass increased straightly with the increase number of animals stocked for unit productive. The values of income of carcass as gutted weight, clean barrel, fillet, head and grease visceral didn t present significant difference (p>0.05) between the treatment. However, the total length and pattern, gain weight, total weight and hipathossomatic indices presented significant difference (p<0.05) and effect quadratic of the treatment. The chemical analyzes of the animals carcass didn t differ, statistically (p>0.05) to the variable dry material, protein and mineral material, so that, the higher lipic deposition was watched at fish produced in density 50 fish per m3. The varieties erythrocitics as hemoglobin and hematocrito didn t present difference statistics (p>0.05) to the treatment used, however, the total erythrocitics and the glucose differed significantly (p<0.01 and p<0.05, respectively) between the densities. It was concluded that the best density to the farm of piracanjuba in cages is between 58and 75 fish per m3