By Lenny Pierce
Species: Astyanax mexicanus
Range: Flooded caves of northeast Mexico
Weird Feature(s): Navigation via pressure reading, lack of pigment, lack of eyes
How do you find your way through complete darkness? If you’re like most of us, you do it by knocking over everything in the room before finally finding a light switch. If you’re like the Mexican blind cave fish, you do it by creating a force field that allows you to sense your environment so well that you don’t even need eyes.
Scientists have long wondered how the Mexican blind cave fish is able to move so nimbly through its pitch black environment. And they knew it wasn’t super sensitive eyes – they don’t have any. Roi Holzman of Tel Aviv University took a closer look at the behavior of these fish and eventually noticed that they sucked water into their mouths and expelled it out their gills unusually often. To figure out if this might be connected to their navigational strategy, Holzman and his team did something that’s really mean to do to blind things: they rearranged all its stuff, moving all of the objects in the fish’s enclosure to see how it would get its bearings with the new …read more