Corallizoanthus aureus, glowing deep-sea zoanthid from southern Japan

A deep-sea zoanthid found living on Pleurocorallium coral colonies at the entrances of karst caves near Minamidaito Island in southern Japan, collected at 385 m. Its polyps are bright yellow, and its name, aureus, means golden. When disturbed it flashes green light, the first documented bioluminescence inside a deep-sea cave. No spontaneous light was observed and no symbiotic bacteria were found, so the flash may serve a defensive or burglar-alarm role, though its function is not yet known. News article: https://www.europesays.com/japan/118009/ [https://www.europesays.com/japan/118009/]