With their vivid colours and beak-like mouths, queen parrot fish are among the most eye-catching inhabitants of coral reefs – and at night time they have a special magic trick...
How do parrot fish make a mucus bubble?
Come sundown, this watermelon-sized Caribbean gem slips into a crevice and, using special glands behind its gills, secretes a bubble of mucus that swells up and over its head like a diving helmet. The pouch spreads towards the fish’s tail and, within 30 minutes or so, the fish is resting inside a surprisingly spacious sac of slime.
- Mucus and slime: Is there a difference and why the natural world can't get enough of the lovely gunk
- "It doesn't come much weirder than having a see-through head!" 16 strangest, weirdest fish in the world, including one that can incredibly live out of water
Why do parrot fish make a mucus bubble?
The clammy cocoon – in which the fish spends the entire night – has many benefits. It is laced with antibiotics that kill known parrotfish pathogens, and also physically blocks blood-sucking parasites from getting near the fish. In addition, it appears to seal in the sleeper’s body odour, masking it from scent-tracking predators such as moray eels.
And the instant the pod is disturbed or torn, its owner wakes up and high-tails it out of there. It’s like a high-tech tent with a mosquito net and burglar alarm system.
But the queen parrotfish’s slimy behaviour doesn’t end there. Another gland constantly churns out a second type of mucus that protects the fish’s skin against ultraviolet light – like slime sunscreen.
Most fish have it, but parrotfish can control where it goes. As it flocks to shallow-water
reef-tops each high tide to feed on algae, it slathers on about twice as much of the ointment over its top half as on the rest of its body. This allows the queen parrotfish to browse for food all day without burning its back, and also not waste the ‘sunscreen’ on parts where the sun rarely shines.
- This bizarre animal creates its own sunscreen by secreting a waxy substance 40 times more powerful than morphine
- How do animals near the equator survive the tropics? The ingenious survival tactics rainforest creatures use, including homemade sunscreen.
Main image © Humberto Ramirez/Getty Images
