Three species of freshwater fishes, namelyO. punctatus, M. vittatus andB. stigma, were taken to establish the effect of temperature on the frequency of heart beat. InO. punctatus, experiments were made on three different size groups to illustrate the differences in the heart rate between older and younger individuals. The response of heart in all the species is very similar. The decrease in temperature is accompanied with a fall in the frequency of heart beat and its subsequent increase is followed by a steady rise. Younger individuals show greater susceptibility to temperature changes than the juveniles and the adults. The temperature characteristics of the heart rate have also been studied by using temperature coefficients Q10 and?. Both these coefficients have been found to vary and it is suggested that the heart rate like other biological processes of poikilothermous animals is dependent on an optimum range of temperature as both high and low lead to an inhibition of vital activity.
- 1 - sciences appliquees, technologies et medecines
- 2 - sciences biologiques et medicales
- 3 - sciences biologiques fondamentales et appliquees. psychologie