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A thermistor probe was used to study deep (white) muscle temperature of five species of freshwater fishes at rest as well as that of exercising and resting trout. The resting deep muscle temperatures were 0.1 to 1.1 C higher than the water temperature. In exercising trout, temperatures of the deep muscle were the same as the temperature of the water.
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John Mark Dean (1976) studied this question.
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