1 Cell to Urchin

© 1998 Chris Patton, Stanford University
This animation traces the development of the sea urchin from

the single fertilized cell to

the baby sea urchin.
Some of the steps along the way:

At the forth division the micromeres form

The swimming blastula "hatches"

Gastrulation forms the mouth from the anus

Prism stage. Embryo starts to feed

Early Pluteus, about 3 days from start

Late Pluteus, about one week

Metamorphosis happens at several months

Producing the baby sea urchin