Produção de biomassa e teor proteico de Daphnia magna (Straus, 1820) submetida à três diferentes dietas

Abstract

The use of live feed has been recommended in the larval stage of several species of fish, as it provides better survival and growth results when compared to those obtained with artificial diets. Therefore, the present study aims to evaluate the biomass and protein content of Daphnia magna submitted to three different diets. For this, three diets were evaluated: diet A (alga Scenedesmus acuminatus) at a concentration of 1.5x107 cells / mL per individual, diet B (cattle manure) at concentration of 13g / L and diet C (S. acuminatus and bovine manure) at Concentration of diet A and B over a period of 21 days. The experimental design was completely randomized, with three replicates of each treatment, the experimental unit consisting of polyethylene containers with capacity for 20L containing 10 neonates of Daphnia magna. The experiment was repeated three times, totaling 63 days of study. Every two days the physical parameters like temperature, Ph, oxygen and dissolved oxygen were measured. At the end of the experimental period, nutrient quantification of culture water and diets (phosphorus, nitrite nitrite, ammoniacal nitrogen, total nitrogen and organic nitrogen) were performed and the final biomass and protein content of the D. Magna The data obtained were evaluated in the STATISTICA 7.0 program. Diet C provided the highest mean biomass value, followed by diet A and B, with values of 344.12 g, 157.71 g and 81.93 g, respectively. The D. magna fed with diet B had a higher protein content of 2.56%, followed by D. magna fed diets C and A, with 2.17 and 1.32%, respectively. It is concluded that diet C is the most viable for feeding Daphnia magna.