One of the world’s rarest fish, the “demon fish,” discovered beneath a military base

in Alabama, USA, where chemical weapons were produced during World War II, Redstone Arsenal military facility, scientists identified a cave fish previously unknown to science. The study of the new species Scientific Reports was published in the journal.

The new species was named Demogorgonichthys arcanus Scientists linked the name to the Demogorgon character from Netflix’s popular series “Stranger Things” as well as to an underworld spirit from Greek mythology. Experts consider it one of the rarest cave fish in the world.

The discovery was made by chance during follow-up observations in Bobcat Cave. Study leader Matthew Niemiller, a biologist at the University of Alabama, fell into a pool while moving through the cave and noticed strange fish hiding beneath a rock. He managed to film them with an underwater camera.

After the images were analyzed, researchers determined that the fish differed significantly from the southern cavefish previously known in the region. The new species was found to have a distinctive hump on its head, a longer snout and differently structured fins.

Subsequent genetic analyses showed that the fish belonged to none of the cavefish groups recorded to date. Researchers also identified distinctive mutations in genes associated with rhodopsin, the protein responsible for vision. This indicates that the species lost its eyesight through independent evolution in a completely dark environment.

Experts note that the newly identified species lives only in Bobcat Cave. Its population may therefore be extremely small. In addition, because the cave is connected to the outside environment through groundwater, the risk of pollution remains.

The study’s authors Demogorgonichthys arcanus could qualify as a highly endangered species under international nature conservation criteria. The exact population size of this rare fish is not yet known, as many of them live in cave areas that are difficult for humans to access.