Green Sea Urchin, Acadia National Park, Maine

Underwater photo of green sea urchin extending tube feet.

Strongylocentrotus droebachiensis, commonly known as the green sea urchin because of its characteristic green color, is a species of sea urchin commonly found in northern waters all around the world including both the Pacific and Atlantic Oceans to a northerly latitude of 81 degrees and as far south as Maine (in the U.S.) and England.