Zebrafish are widely studied in biology, and for good reason. Not only are they hardy and easy to grow in a lab, their embryos are translucent, so it’s easy to observe how they develop from a single cell into a newly hatched fish.
A fertilized zebrafish egg develops and hatches within 48 hours. It then takes three months for it to reach adulthood.
1 hour
The fertilized egg has already divided twice, making four cells.
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2 hours
As the cells continue to divide, they get smaller and smaller (there are now 128 of them).
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5 hours
The curved line shows where the body will soon take shape.
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14 hours
The backbone and eyes are beginning to form.
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17 hours
The brain begins to form. The body continues to grow longer.
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24 hours
Muscles are taking shape and beginning to twitch.
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48 hours
The zebrafish is ready to hatch.
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Although zebrafish don’t look much like humans, our embryos follow a similar path during early development, so we can study zebrafish to learn about human development.
For example, there are genetic mutations in zebrafish that cause heart defects that are very similar to mutations that cause defects in human hearts. You may encounter some of these mutant zebrafish in this exhibit. They’re easy to spot because their strangely shaped hearts don’t pump blood very well.
