Sea Urchin

close view of two purple sea urchins on rocks underwater
Purple Sea Urchin. NOAA

Quick Facts
Type: Echinoderm

Diet: Herbivore; Brown and green algae

Average lifespan: 20 years

Average size: 2-5 in.

Average weight: Unknown

Did You Know?
Scientists have discovered that the red sea urchin has one of the longest lifespans of any animal. Red sea urchins have been found that are believed to be 200 years old!

Last updated: November 16, 2016