Zebrafish Embryo (IMAGE) University of Sussex Caption This is an example of the electrocardiogram mapped from the embryonic zebrafish heart three days after fertilization. Credit Dr. Elizabeth Rendon-Morales Usage Restrictions Please credit as above License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.