Zebrafish embryo (IMAGE) NIH/National Human Genome Research Institute Caption Brightfield image of a two-day old zebrafish embryo. Credit Erin Jimenez, Ph.D. Usage Restrictions No restrictions. License Public Domain 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.