GROWTH AND PRODUCTION OF BULLFROG RANA-CATESBEIANA SHAW, 1802, AT 3 STOCKING DENSITIES IN A VERTICAL INTENSIVE CULTURE SYSTEM

Newly metamorphosed froglets of Rana catesbeiana were experimentally c ultured in a three-dimensional (vertical) system at 50, 100 and 200 an imals m(-2). The culture system consisted of nine sections (three per treatment) in a vertical array where frogs were provided with food and water in replaceable troughs. After 8 weeks, frogs stocked at 200 m(- 2) developed a severe bacterial infection, leading to high mortality a nd the cancellation of this treatment. There were no significant diffe rences (P>0.05) among frogs stocked at 50 and 100 m(-2) after 175 days , reaching 118 g and 105 g mean final weight, respectively. Survival w as inversely related to stocking density, amounting to 72% and 65% for 50 m(-2) and 100 m(-2), respectively. Yields were 4.33 kg m(-2) and 6 .87 kg m(-2) for the former and the latter densities, respectively, th us demonstrating the high production potential of vertical frog rearin g systems. These results indicate lower yields than reported in studie s using two-dimensional systems, but per unit area, they gave higher y ields.