A fish that barely sleeps could help turn humans into all-night party animals

The Mexican cavefish have no eyes, little pigment, and require about two hours of sleep per night to survive. The fish species Astyanax mexicanus exists in two populations. The cavefish, top, evolved to have no eyes and little to no pigment. The surface dwelling fish, below the cavefish, have eyes and more pigment. Alex Keene/Florida Atlantic…