Project Description

During a shallow dive at Saxe Point I noticed this unusual pale short-spined green sea urchin (Strongylocentrotus droebachiensis).  The thick compact spines are unusual for a green urchin.  The tentacles on this urchin are purple, which is apparently a major factor in the identification of this being a green urchin.  Pale urchins (Strongylocentrotus pallidus) have white tentacles.  The green sea urchin is a herbivore and eats a wide variety of algae.  It’s interesting how the tube feet of this urchin cover much of its surface area.  The green sea urchin can grow to 3.6 inches (9 cm) across, with a range that is circumpolar and includes Japan, as well as northern Alaska to northern Washington.