15 specimens of a previously unknown species were found in a cave during a cavefish diversity survey in southern China. The species was named Sinocyclocheilus longicornus.
The unicorn fish has an unforked horn-like structure on its forehead and small degenerated eyes, meaning it cannot see well. However, since it lives in total darkness, it does not need them. Some species of the same genus do not have the horn-like structure and live in a more lit environment. Therefore, researchers believe that the horn development could be associated with life in the dark.
Cavefish often have an unusual structure and habits. For example, in Mexico, they are quite plump, while in Thailand, they have learnt to walk and even climb.
The cavefish is 10 to 14 centimeters long, and there is no pigment in its scales. The creature lived in a pond no more than a meter deep and about 1.8 meters wide.