Strongylocentrotus purpuratus (Purple sea urchin)
2005 Mary Jo Adams
purple sea urchin prefers high-energy beaches where it burrows a
niche into soft rock. Its spines are relatively short and
stout; their length is about one third the diameter of the animal's
test (shell). The test may grow to a diameter of 4 inches.
Color is usually bright bluish-purple. Occasionally
an individual, especially a juvenile, may be found with green tinted
spines. The purple urchin feeds primarily on kelp.
Those individuals who find themselves too large to escape their
crevice or burrow subsist on drifting seaweed and may absorb some
nourishment directly from the water. This species employs
its tube feet to collect shell debris and seaweed, which it then
uses as camouflage or shade. The purple urchin may become
prey to sea otters, sea stars, or fish and can be found from the
lower intertidal to a depth of 525 feet.
This page was created by Mary Jo Adams on 12/7/05.