Circadian variation of Spilotes pullatus (Colubridae)

Abstract

The circadian rhythm of the mean heart rate and RR and QT intervals in electrocardiograms were determined for Spilotes pullatus in normal cycle (day/light and night/dark) conditions, during springtime. The statistical analysis of the results revealed significant differences among time intervals, using Tukey's test. Heart rate and body temperatures demonstrated considerable variations in their respective values over the 24h monitoring period and long circadian rhythmicity in the electrocardiogram intervals (p<0.05). In addition, significant reductions of the heart rate and an increase in RR and QT intervals were also observed. Multiple influences on QT interval dependence were found, not only in circadian and gender modulation, but also in heart rate.

Keywords

• body temperature
• electrocardiogram
• QT interval
• RR interval
• snake
• Spilotes pullatus