The Invisible Pirate

Many aquatic animals use camouflage to disguise themselves. From exquisite Leafy Sea Dragons to venomous Stonefish, the rivers and oceans of the world are full of creatures that use deception and concealment to their advantage. But as humans are very visually-oriented species, it’s easy for us to forget that camouflage goes beyond the visible and that “chemical camouflage” can conceal an animal’s smell and taste as well.

But while visual camouflage hides creatures from any prying eye, chemical camouflage normally only works in tricking a specific species – usually a specific predator or prey. The chemical camouflage of the Pirate perch (Aphredoderus sayanus) is a different matter however, as scientists have discovered that it works on every animal they’ve tested it on so far.

Living in the clear, warm waters of the central and eastern US, the aptly-named Pirate perch is a nocturnal predator that will eat almost anything in its path, from insects to fish. And its success is due in large part to its amazing ability to camouflage its scent. Scientists have no idea how the pirate perch does it, but they theorise that it might have evolved not to release certain telltale chemicals, or to mask them with a different chemical.

However it works, the nifty trick gives the perch a significant advantage as the scent is more important in water, where chemical signals travel widely and visibility can be limited. Perhaps most amazingly though, the perch is the first animal ever found to have this “global” chemical camouflage, making the canny little predator the only animal in the world that literally cannot be sniffed out.