Mucus Saves the Day!

Norbert Wu/Minden/FLPA

Let’s say that you’re a fish living in a coral reef. (If you already live in a coral reef, this will be easy.) When it gets dark, you like to slow down and take it easy…but it’s hard to relax with all the predators (like moray eels) that want to eat you. Almost as bad, there’s loads of parasites (called gnathiids) that want to suck your blood!

So to solve the problem, you spit. That is, you swim into a cozy little part of the coral and you start spitting up mucus to wrap yourself inside of. That’s what parrotfish and wrasses do each evening!

By Patrick Hoesley

These fish have mucus glands near their mouths that allows them to create their own mosquito nets each night. No moray eel wants to eat a fish wrapped in what looks like a spider web. And most parasites can’t get through the mucus!

And humans can also protect themselves from predators and parasites with mucus. If you’re bothered by a bully or someone who constantly borrows money from you, try coating yourself with mucus. I’ll bet they stay away!

New Scientist article on this topic here.