Deep-sea, Cold-water coral

Deep-sea, cold-water coral Lophelia pertusa and associated animals. Branching white structures at left and top are live Lophelia, with polyps extended; branching orange-brown structures at bottom and right are dead Lophelia overgrown by biofilm. A pencil urchin (looks like a ball with spines) is visible near bottom of image. Blue encrusting sponge grows on dead coral in center of image. Barely visible above the blue sponge are the delicate tentacles of feather-duster polychaete worms.