The green sea urchin has one of the longest, most awkward scientific names, Strongylocentrotus drobachiensis. The genus Strongylocentrotus loosely translates to "round, pointed" and drobachiensis comes from the city of Drobach, Norway (Source: Woods Hole MBL).
Despite their immobile appearance, sea urchins can move quite quickly using their long, clear tube feet, and they are fascinating to watch. Sea urchins use their spines for protection and also may camouflage themselves by trapping pieces of algae with their spines. In a tide pool, sea urchins are often found in clusters underneath rocks.
These echinoderms feed on algae using a unique feeding apparatus on their underside called the "Aristotle's lantern," which is comprised of five calcium plates, muscles and connective tissue that allow the urchin not only to scrape algae, but to chew it into tiny bits.