Unlike most Mediterranean sea fans, the white sea fan hosts symbiotic algae (zooxanthellae) that give it its pale, faintly greenish color. It lives in shallow, well-lit waters, which makes it especially vulnerable to marine heatwaves.
What defines this group — Cnidarians (corals, anemones, jellyfish)
Corals, anemones and jellyfish: the same simple animal, anchored to the bottom or drifting in open water.
All armed with cnidocytes, harpoon cells that fire on contact.
A body arranged in rays around a single opening, serving as both mouth and exit.
Hard corals host algae in their tissue: it is their departure that causes bleaching.