Biologists have long wondered exactly how fish emerged from the sea and transitioned into vertebrates that could walk on land. To date, most of the information on that shift has come from fossils,
but scientists reported Thursday they have found that a species of fish located only deep in the caves of Thailand walks the same way land vertebrates do. The blind waterfall-climbing fish, Cryptotora thamicola, first discovered in 1985, has skeletal features similar to a salamander—including a fully formed pelvis—that enable them to climb up rock walls and feed on microbes and organic matter as water comes crashing down on them, the researchers wrote in Nature Scientific Reports. “Functionally, it makes perfect sense, but to see it in a fish is incredibly wild,” said Brooke Flammang, an expert on biomechanics at the New Jersey Institute of Technology and lead author of the study. The discovery could help more fully explain how life evolved from the sea to land.
D.S.
A waterfall-climbing fish.