Researchers have found a blind cavefish that walks up waterfalls. In a study published in Scientific Reports, they said the fish, Cryptotora thamicola, is incredibly rare due to its walk, which seems like a four-legged animal’s saunter.

The fish is a blind cavefish, but what make it unique are its morphological features. These were previously seen in four-footed mammals and amphibians, said Brooke E. Flammang, a researcher from the Jersey Institute of Technology and an author of the study. Cryptotora thamicola’s pelvis and vertebral column allow it to support its body weight against gravity, the author added.

According to Flammang, she first spotted the unique nature of the pink fish in a video captured by Daphne Soares, another author of the study. The salamander-esque wiggle was surprising, said Flammang. There are some other fish species too that capitalize their fins to use as feet, but Cryptotora thamicola was using the skill in a rare way, as per the researchers.

The fish found in a cave of Thailand was climbing its way to the top of a mountain. “From an evolutionary perspective, this is a huge finding. This is one of the first fish that we have as a living species that acts in a way that we think they must have acted when they evolved from a fluid environment to a terrestrial environment”, said Flammang.

The waterfall-climbing cave fish’s movement is really weird and surprising, said biologist John R. Hutchinson from the Royal Veterinary College at the University of London. It is a huge discovery. The new find has suggested that there are several interesting things about the fish world that are still a mystery, added Hutchinson, who wasn’t part of the study.