Watch a Fish That Can Walk Up Waterfalls

A walking cavefish just gave scientists a glimpse 400 million years into the past. Discovered in Thailand, these blind fish have now been closely documented walking and climbing waterfalls in complete darkness using a gait similar to four-limbed vertebrates like salamanders.

The cavefish use a mechanism akin to using limbs and may be part of the evolutionary foundation for land mammals’ transition from water to land. Researchers next plan to study the role the fish’s muscles play in this weird, wonderful locomotion.