Related to starfish, sea urchins have been nicknamed “sea hedgehogs” (“urchin” is an old word for “hedgehog”). With the five small teeth located on their underside, sea urchins scrape fine algae off rocks. They also feed on large seaweeds, like kelp, their favourite.

Between their spines are podia (tube feet), in the shape of suction cups, which enable them to move and grip onto rocks.

The Gulf of St. Lawrence is home to 21 species of starfish. The most common have 5 arms, but others have 6, 8 or even 14.

Their arms, with their hundreds of tiny, adhesive tube feet, are used to move around. They are also used to grab molluscs. Some species evert their stomach to digest their prey on-site, before reabsorbing both into their body.

Surprisingly, some starfish can lose an arm, even be cut in half, and regenerate completely within a few months.