Various species of parrotfish, including the queen parrotfish, Scarus vetula, create a mucus coccoon around themselves, particularly at night.
Before entering a sleep state, some species secrete mucus from an organ in their heads to form a protective transparent bubble that may serve to mask their scent from nocturnal predators such as moray eels.
The envelope also serves as an early warning system, giving the fish time to escape if a predator disturbs the membrane.
This video shows parrotfish at night, including one sleeping inside a mucus bubble beneath a rock.
The fish’s skin is also covered with mucus that has antioxidant properties and may help to repel parasites, speed up bodily repair, and shield the fish from ultraviolet radiation.
Matthew Oldfield is a freelance photographer based in Bali, Indonesia, specializing in editorial and documentary images from both above and below the waves. He works primarily with charities, NGO’s, and other organizations working to conserve the environment, endangered species, and disappearing cultures.
