1 Cell to Urchin
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© 1998 Chris Patton, Stanford University
This animation traces the development of the sea urchin from
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the single fertilized cell to
![](media/dp9.gif)
the baby sea urchin.
Some of the steps along the way:
![](media/dp2.gif)
At the forth division the micromeres form
![](media/dp3.gif)
The swimming blastula "hatches"
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Gastrulation forms the mouth from the anus
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Prism stage. Embryo starts to feed
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Early Pluteus, about 3 days from start
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Late Pluteus, about one week
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Metamorphosis happens at several months
![](media/dp9.gif)
Producing the baby sea urchin