Resumo -O objetivo deste trabalho foi avaliar o desempenho e a atividade de amilase em quimo de tilápias-do-nilo macho, linhagem tailandesa, submetidas a quatro diferentes temperaturas. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro tratamentos (20, 24, 28 e 32 o C), seis repetições e dez peixes por unidade experimental. A dieta utilizada foi igual para todos os tratamentos. Aos 55 dias do experimento, o consumo de ração aparente, ganho de peso, conversão alimentar aparente, atividade de amilase e atividade específica da amilase foram avaliados. O consumo de ração aparente e o ganho de peso aumentaram linearmente com o aumento da temperatura. Na conversão alimentar aparente, foi observado efeito quadrático em função da temperatura com melhora na conversão de 1,79 a 1,00 com o aumento da temperatura até 29,15 o C. Observou-se efeito linear na atividade da amilase e na atividade específica da amilase em função da temperatura, com maior atividade de amilase e menor atividade específica de amilase a 32 o C. A temperatura da água influencia o desempenho e a atividade da amilase em tilápias-do-nilo.Termos para indexação: Oreochromis niloticus, enzimas, fisiologia de peixes, piscicultura. Performance and amylase activity in Nile tilapia submitted to different temperaturesAbstract -The objective of this work was to evaluate the performance and amylase activity in chime of Nile tilapia male, Thai line, submitted to four different temperatures. The experimental design was completely randomized with four treatments (20, 24, 28 and 32 o C), six replicates and ten fishes per experimental unit. The diet was the same for all treatments. At 55 days of experiment, apparent feed intake, weight gain, apparent feed conversion, amylase activity and specific amylase activity were evaluated. The apparent feed intake and weight gain increased linearly with temperature increase. For apparent feed conversion, quadratic effect was observed as a function of temperature, showing a conversion improvement of 1.79 to 1.00 with the increase of the temperature until 29,15 o C. Linear effect in amylase activity and specific amylase activity was observed as a result of temperature, comprising high amylase activity and low specific amylase activity at 32 o C. Water temperature influences the performance and amylase activity in Nile tilapia.

Performance and enzymatic activities of the bullfrog tadpolesAbstract -The objective of this study was to evaluate the performance and the digestive enzyme activity in bullfrog tadpoles, fed with commercial ration during 60 days, at the density of one tadpole per liter in 30 L boxes. The parameters measured fortnightly were: survival, length, weight, ration consumption, and amylase, lipase and trypsin activities. There larger growth of the tadpoles occurred from the 15 th to the 45 th day -20.61 mm. During the first 15 days, the tadpoles had the largest specific growth rate, 16.7% per day. From the 45 th to the 60 th day, the tadpoles had the largest weight gain, 3.98±0.73 g, the largest ration consumption, 14.40±1.14 g and the best feed conversion, 3.67:1.0±0.18. There was significant increase in enzyme activities after the 30 th day. Relationships were observed between the specific enzyme activities and the different development phases of the tadpoles.