Effect of temperature on heart rate in Terrapene ornata

The effect of temperature on the heart rate of turtles has not been thoroughly studied. It is generally accepted that the rate varies directly with temperature. Until the work of Hutton et a][. (1960) and Akers and Damm (1993), the effect of temperature on turtle heart rates has been reported only in passing in other studies. In these studies the heart rate was generally measured at only a few temperatures.

Most of the work on turtles has been limited to aquatic species, particularly to Pseudemys. Heart rates that have been given in the literature for a specific temperature and under control conditions are summarized in Table 1. Benedict (1932), working with two Testudo denticulata, found that long periods of fasting lowered the heart rate. He postulated that heart fate may be an index of metabolic activity. Woodbury (1941) reported heart rates of 2 beats per minute at 0°C ranging to 70 at 30°C. He did not identify the species he used nor did he specify the exact methods he employed.