Living on the edge! A squat lobster seen on a glass sponge, or hexactinellid, during a dive to explore a guyot during the 2016 Deepwater Exploration of the Marianas expedition.

Glass sponges have skeletons made of silica, which is the same material used to make glass, but glass sponges are not glass, per se. Check out this ocean fact to learn more about these sponges.