Weight gain of bullfrog (Rana catesbeiana, Shaw) reared in individual cages of different sizes

A trial was set up at the Experimental Frogculture of the Parque Fernando Costa, Sao Paulo, Brazil, to compare the weight gains of bullfrogs (Rana catesbeiana, Shaw, 1802) reared in individual cages of different sizes. The experimental design consisted of four treatments, with five replicates. All the 20 cages had 25 centimeters, long but each treatment had the following widths: 25, 20, 15 and 10 centimeters. The frogs were weighed once a month and during the experimental period of five months the only alimentary source was represented by Rana catesbeiana tedpoles. The data was analysed by means of analyses of variance with regression by the orthogonal polinomial (P < 0,01). There was a significant effect, showing that frogs reared in cage with 25 cm in width had the best weight gain. The mean weight gains from the bigger to the smaller cage were: 29,08 plus or minus 7,42 g; 21,86 plus or minus 6,77 g; 19,98 plus or minus 4,13 g e 18,98 plus or minus 5,20 g, demonstrating that it was possible to rear Rana catesbeiana in individual cages.