Green sea urchin

Strongylocentrotus droebachiensis, commonly called the Green Sea Urchin or Common Sea Urchin, is a species of sea urchin that belongs to the family Strongylocentrotidae.

This is a regular, almost hemispherical sea urchin, ranging in colour from pale green to dark green, often tinged with red on its oral (underside) surface. The ambulacral areas often form a pink, five double-branched star on the aboral (upper) side, from which long purple tube feet (“podia”) extend. It measures up to 10 cm in diameter and 4 cm in height, with spines (“radioles”) reaching a maximum of 1 cm.

This sea urchin inhabits the cold oceans of the Northern Hemisphere: the northern Atlantic and Pacific Oceans, and the Arctic Ocean, with significant penetration into fjords and other gulfs, such as the Gulf of St. Lawrence.