Pirate Perch: The "Invisible" Fish

The other day I found a cool story over on the website of Popular Science about the pirate perch. These little fellows, which max out in length around 6 inches, inhabit waters all throughout North America. While the species is of no particular interest to pan-fishermen jigging through the ice, it apparently has scientists baffled. It seems the pirate perch is the only species on the planet that can make itself chemically "invisible" to its prey.

According to the story, pirate perch are solitary and nocturnal, making them very hard to study. But a few researchers managed to get their hands on some. Using mesh bags and trash cans, they placed the perch and several other predator species in areas where frogs and beetles lay their eggs. In the areas where other predators were placed, the frogs and beetles felt threatened and, therefore, did not lay any eggs. Oddly, the frogs and beetles where the pirate perch were placed laid plenty of eggs and could have cared less that the perch were present. This tells researchers that the perch must have a cloaking device, but here's the twist: There are both visual (camouflage) and olfactory (scent masking) forms of cloaking in the animal world, and the pirate perch isn't using either of those.

The best guess of researchers is that the pirate perch actually emits a chemical that stops the beetles and frogs from sensing its presence. That's some pretty next-level stuff. If you could put whatever juice the perch are making in a spray bottle and slather up your flats booties or waders, the trout and bonefish would never see you coming.