Diurnal rhythmic activity in the heart-beat of the scorpion Heterometrus fulvipes C. L. Koch
Naidu, V.D.; Padmanabhanaidu, B.
Indian Journal of Experimental Biology 14(1): 1-5
1976
ISSN/ISBN: 0019-5189 PMID: 955682 Document Number: 96649
Analysis of the heart-beat in the scorpion Heterometrus fulvipes (Koch) showed that there were diurnal variations with the maximum activity at 20 h and the minimum at 8 h. Neurohormones produced at different times of the day from the cephalothoracic nerve mass differed in their influence on the heart rate. The variations in the heart rate appear to be due to differential effects of neurohormones on the acetylcholine-synthetic mechanism and energy-yielding processes, which, in turn, produce variations in the spontaneous electrical activity of the cardiac ganglion, resulting in changes in the heart rate.