Tentacles of the sea anemone Heteractis magnifica fluorescing bright orange under blue light at night. This anemone is the source of a fluorescent protein used in biological research to tag cells. Also visible are juvenile black and white three-spot dascyllus fish (Dascyllus trimaculatus), who shelter in the anemone. These orange variants of the anemones are usually found below 30 metres deep. Filmed at Marsa Shagra, in the Egyptian Red Sea.