Green Sea Urchin    Strongylocentrotus droebachiensis



The green sea urchin is one of several closely related species of urchin living in Washington.  The others are the red sea urchin and the purple sea urchin, however those species range further south to Baja California while the green stops at the Oregon border. All of the species occur north to Alaska.  The green urchin also has shorter spines than it’s cousin’s and prefers quiet waters.  It grows up to 4 inches in diameter.


Urchins are relatives of sea stars and sea cucumbers but the spines have become very large and mobile.  Tube feet are retained, and along with the spines, are used for locomotion and respiration.


The green sea urchin, like other urchins, feeds entirely on plant material.  In fact they have a very complex and specialized, five-toothed chewing devise commonly called Aristotle’s Lantern.  they search for plants on rocky areas as well as soft bottoms.  They are fed upon by fish, sea otters, several sea stars and humans (who eat the eggs).