Describing animal growth rate using non-linear models allows a detailed evaluation of growth behavior. Four non-linear models were used to fit weight gain and total length data of bullfrog (Lithobates catesbeianus) tadpoles, as follows: Gompertz, Y = A exp (-exp (-b (t-T))); Von Bertalanffy, Y = A (1 - K exp (-B t))³; Logistic, Y = A (1+ K exp (-B t))-1 and Brody, Y=A (1 - K exp (-B t)). We used 3,240 tadpoles, with average initial weight 0.044 g and average total length 12.79 mm, stage 25 Gosner. The measurements were conducted every ten days on 10% of the animals in every tank. The criteria used to select the model that best described the growth curve were: Residual Mean Square (RMS); determination coefficient (R²); residual graphical analysis; residual mean absolute deviation (MAD). Brody mathematical model was not a good fit for weight gain and total length, while Von Bertalanffy model underestimated tadpole initial weight, thus showing the difficulty of mathematical models to describe biological data at this growth stage. However, the Gompertz and Logistic models were considered to be an adequate fitting to describe growth rate and total length of bullfrog tadpoles in captivity.

This study evaluated the quality of sperm cryopreserved with dimethylsulfoxide (DMSO) or methanol, of Thailandtilapia (Oreochromis spp.) fed diet with different oilsources. eightyThailand tilapia fed different oil sources (T1: linseed oil, T2: soybean oil, T3: fish oil, T4: corn oil) and were analyzed as for motility rate, and duration of motility in ‘fresh sperm’ and after cryopreservation. No significant difference was found for the final weight, total length, rate and duration of motility of fresh sperm in the different treatments. Significant differences were observed between fish, corn and linseed oil treatments on the rate of motility relative to other different oil sources with the cryoprotectant DMSO prior to freezing. After thawing, fish fed diet supplemented with fish oil presented a significantly higher rate and duration of sperm motility. Nevertheless, for better reproductive parameters after freezing, it is recommended the use of fish oil associated with cryoprotectant methanol.

A carne de rã apresenta alta digestibilidade, evidenciando a importí­¢ncia de sua utilização em dietas especiais. O objetivo do estudo foi avaliar o potencial da utilização da carne de rã nas dietas hospitalares e em dietas recomendadas pelos médicos e, ainda, promover o consumo. Foram realizadas entrevistas em hospitais e consultórios da cidade do Rio de Janeiro (RJ, Brasil). A pesquisa identificou que 72% dos entrevistados - médicos, nutricionistas e responsáveis por cozinhas hospitalares - não conhecem as caracterí­­sticas nutricionais da carne e que 50% acreditam que há dificuldades na sua utilização e destacaram a falta de disponibilidade no mercado e o preço elevado do produto. A carne de rã é considerada um alimento saudável, mas a importí­¢ncia da utilização e as formas de preparo precisam ser divulgadas.