Life Sciences

Look Inside a Zebrafish Egg

An enlarged view from a microscope shows the stages of development of the fertilized egg of a zebrafish from a single cell into a complete organism. All organisms that reproduce sexually develop in a similar manner. A progression over a period of 48 hours shows the early division of cells becoming smaller as they increase in number, their migration over the yolk, the specialization of cells into different organs, and, finally, the completed zebrafish.