Gain in weight in tadpoles of Rana catesbeiana Shaw, 1802, in intensive culture under different densities of population

Abstract

In the experimental outdoor facility planned for frog culture in the Fishery Station of Pindamonhangaba, São Paulo State, Brazil (22°55'55"S and 45°27'22"W), under intensive system of culture, the gains in weight in tadpoles of Rana catesbeiana Shaw, 1802 in 4 different densities of population were statistically compared. These densities were: 5, 10, 15 and 20 tadpoles per liter. The experimental period was October 21 through December 16, 1983. The statistical design was that of an experiment in random blocks, with 4 treatments and 5 repetitions. The employed tanks, 20 in all, were of the same dimensions and built in cement. The analysis of variance taking in account the regression revealed that the gain in weight decreases with the increase of the population density (linear component significant, P<0.01).