Samuel Lopes Lima

Influência da Temperatura Ambiente no Desempenho da Rã-touro, Rana catesbeiana (Shaw, 1802) na Fase de Recria

An experiment was conducted to evaluate the effect of environmental temperature on the bullfrog performance in the growing phase. Four hundred and fuve frogs, weighing 37,5±1,5 grams, were assigned to a randomized experimental design with three treatments (20,2±0,7°C, 25,1±0,4°C and 30,2±0,5°C), five replicates (boxes) and 27 frogs in each replicate. The experimental period was of 45 days, being ten days for adaptation of the frogs to the installations and the feeding. The daily feeding comprised one commercial ration of trout with 45% of crude protein and a fly larva for attraction. The performance of the animals was evaluated and found that the temperature affected significatively affected the consumption of the ration and fly larva and weight gain, however the feed:gain values were not different in the three treatments. The development of the bullfrog is directly related to the environmental temperature, which influences the consumption and utilization of food by the animals.

Efeito da temperatura sobre o desempenho da rã-touro (Rana catesbeiana Shaw, 1802)

Este estudo foi realizado para avaliar os efeitos do ambiente sobre a performance de ra-touro (Rana catesbeiana Shaw, 1802), criada em gaiolas de fibra de vidro instaladas no interior de estufas climatizadas. Apos um periodo inicial de 15 dias de adaptacao as instalacoes, a temperatura constante de 25,0oC, os seguintes tratamentos foram aplicados: temperaturas de 23,0; 26,0; 29,0; 32,0; e 35,0oC, por 30 dias, para ras com 100 g PV inicial; 24,5; 26,0; 27,5; 29,0; 30,5; e 32,0oC, tambem por 30 dias, para ras com 20 g PV inicial; e a combinacao das temperaturas de 26,0 e 29,0oC com os fotoperiodos de 8, 12 e 16 h de luz a cada 24 horas, para ras com 100 g PV inicial. Derivando-se as equacoes de regressao que explicam os efeitos de temperatura sobre o desempenho das ras, estimaram-se melhores ganhos de peso a temperatura de 27,6 e 30,1oC, para ras com 100 e 20 g PV inicial, respectivamente, com melhor crescimento a 28,2oC, para as ras de 100 g PV inicial, e a 29,7oC, para as ras de 20 g PV inicial. A temperatura interagiu com fotoperiodo nos seus efeitos sobre ganho de peso e crescimento corporal, peso e rendimento de carcaca, consumo de alimentos e conversao alimentar.

Estufas climatizadas para experimentos ambientais com rãs, em gaiolas

Six acclimatized incubators were initially installed in the Experimental Frog Farm of the Federal University of Vicosa and later in Experimental Frog Farm of the Federal University of Rio Grande, with the objective of accomplishing experiments to evaluate the effects of the environment on frogs performance in cages of fiber glass. Environments with temperatures of 25oC and photoperiod of 12/12 hours of light/hours of darkness (h L/D) were available to frogs adaptation during 15 days before each experiment. The treatments consisted to simulate environments with temperatures varying from 20 to 35oC and photoperiods of 8/16, 12/12 and 16/8 h L/D. They were accomplished experiments with bullfrog (Rana catesbeiana Shaw, 1802) and with butterfrog (Leptodactylus ocellatus Linnaeus, 1758). In these incubators it was possible to estimate that: a) the highest weight gain of bullfrog was obtained between 27.6 and 29.7oC, with better growth between 28.2 and 30.1oC; for butterfrog the best gain and alimentary conversion were verified at 28.6 and 28oC, respectively; b) temperature interact with photoperiod affecting the frogs performance and gonadal development; c) at 27.7oC (temperature of thermal comfort) there will be less frogs inside of water; d) the highest cloacal temperature: 32.1oC, in the dry part, and 33.8oC, inside of water, at 35oC, evidenced the bullfrog thermoregulation; e) the tetraiodotironine (T4) level in the plasm decreases in the temperature of thermal comfort; f) butterfrog was conditioned to the routine handling, coming around feeder at eater time.

Efeito da temperatura e do fotoperíodo sobre o desenvolvimento do aparelho reprodutor de rã-touro (Rana catesbeiana Shaw, 1802)

The effects of the temperature and of the photoperiod on the bull frog sexual maturation of frogs weighing 94.22 g ± 12.03, maintained for thirty days under temperatures of 20, 23, 26, 29, 32 and 35°C, with photoperiod of 12/12 hours of light/hours of darkness (h L/D), were evaluated. Temperature affected the weights of the fat body and liver, that varied according to quadratic models, and higher weights of fat body at 27.27°C and of liver at 26.81°C were considered. The ovaries heavier than 28.36°C and oviducts heavier than 28.77°C were estimated. Temperature affected the sexual maturation of the frogs, evaluated by numeric indexes. In a longer experiment, frogs with initial weight of 95.31 g ± 8.46, were submitted to the combination of the temperatures of 26.0 and 29.0°C with photoperiods of 8/16, 12/12 and 16/8 h L/D, until they reach the gonadal maturity. Temperature interacted with photoperiod in its effects on the development of the reproductive organs of bullfrog. Temperature affected the diameter of the abdomen/distance relation between the eyes, with higher values calculated for 26°C. It was considered that the highest ovocites diameters are obtained under a temperature of 26.0°C, with photoperiod of 12.6/11.4 h L/D.

Thinking better about high-quality science: a look at some ethical flaws and productivity evaluation.

Programa de Pos-graduacao em Ecologia e Conservacao, Universidade do Estado de Mato Grosso – UNEMAT, Campus Universitario de Nova Xavantina, BR 158, Km 655, CP 08, CEP 78690-000, Nova Xavantina, MT, Brasil*e-mail: pedrov.eisenlohr@gmail.comReceived: October 1, 2013 – Accepted: March 11, 2014 – Distributed: December 31, 2014