Scientists discover bizarre blind ‘demon' fish hiding beneath US Army base in Area 51

Scientists have recently identified an extraordinary new species of blind cavefish living under the U.S. Army Base in Alabama. Despite the fact that the underground caves have been monitored by researchers for over 30 years, researchers were able to locate the fish (Demogorgonichthys arcanus) in Bobcat Cave, a series of connected caves on the U.S. Army’s Redstone Arsenal property in Huntsville, Ala.

Due to its distinctive appearance and exclusive existence deep within the underground caves, researchers have referred to the new species as the “Demon Cavefish.” The name was inspired from the fictional creature from Stranger Things and Dungeons & Dragons.

The researchers from the University of Alabama in Huntsville discovered the fish while conducting a biological survey of Bobcat Cave in February 2025. While conducting the biological survey, they observed that the fish had lost all of its pigment and nearly all of its eyesight due to its adaptation to exist in total darkness below ground level.

Furthermore, the researchers found that the fish lacked almost half of its rhodopsin gene; a component responsible for light sensitivity.

DNA tests showed the fish is related to other North American cavefish. What is most intriguing about the discovery is that researchers believe both species lived in separate parts of the cave and in some cases, the same pools. 

However, since they are not biologically related and do not share a common ancestor, researchers believe that both species evolved the characteristics of reduced eyes and loss of color independently, a phenomenon described as convergent evolution.

Since the discovery of the Demon Cavefish there is growing concern about its potential extinction status.

Because the species has only been documented in one specific cave and surrounding area, researchers feel that if there are any external threats to the species (i.e. contamination or disruption of the water source), then this species could potentially become extinct.

Researchers say that this is another example that demonstrates how long-term research efforts can often miss identifying important species discoveries.