海柳

A soft coral. Though it is built by small jellyfish-like polyps, like hard corals, the polyps produce a fleshy matrix called coenenchyme, rather than hard limestone.

—Predator: gorgons sting and eat small prey in the seawater.

—Upsetting: human psychology suggests that a reef made entirely of soft coral would trigger revulsion or alarm.

Earth analog: octocorals, including sea fans.