Some observations on the influence of stress on ECG patterns in Oreochromis mossambicus and Cyprinus carpio

Electrocardiograms of undisturbed, resting fish as well as disturbed (stressed) fish were recorded by biotelemetry. Both fish species showed marked changes in heartbeat patterns in response to stress with tilapia exhibiting the most pronounced changes. A theory is advanced to account for the marked changes in electrocardiogram patterns of disturbed fishes.