Purple Sea Urchin |More Ocean Resources On a clear, sunny
coastal day, the purple spines of the Purple Sea Urchin
(Strongylocentrotus purpuratus) can be easy to spot in the
inter-tidal zone. Most of the time, sea urchins are stationary
animals that attach themselves to a rock or other hard substrate
in order to scrape off and consume the algae. They can also be
found in deeper water, often around kelp beds, one of their
favorite meals. Sea Urchin bodies, formally called tests, are
round and covered by a hard shell. Like other Echinoderms such
as Sea Stars, their mouth is on the bottom of the body. The
spines are used as a defense mechanism, and while some sea
urchin species are known to be poisonous to humans, the purple
sea urchin is not considered poisonous. Both people and ocean
animals such as sea otters and sea stars consider sea urchins a
delicacy. © 2010 Patricia A. Michaels