Correlation between Activity and Breathing Rate in the Smooth Newt, Triturus vulgaris (Amphibia, Urodela, Salamandridae)

Abstract

In common with many urodeles, smooth newts have 3 respiratory surfaces, the skin, the buccal cavity and the lungs. In association with pulmonary respiration newts in their aquatic phase make frequent ascents to the water surface to gulp in fresh air. A male newt was placed in a tank and the times at which he made breathing ascents and the number of times during the interval between consecutive ascents that he crossed one of the imaginary lines adjoining the lines marked on the front and back walls were noted. There was considerable variation in interbreath intervals shown by 7 newts. A large part of this variation may be attributable to differences in the effectiveness of air exchange between breathing ascents. Sometimes a newt will ascend very soon after the previous ascent, suggesting that he may not have taken in a sufficiently large gulp of air at the first ascent. The correlation between breathing rate and level of activity is to be expected since O2 will be used up faster as activity increases.