Researchers were left stunned when they discovered a new “demon cavefish” in a highly-studied cave beneath a US Army post in Alabama.

Scientists from the University of Alabama in Huntsville (UAH) uncovered a new genus of cavefish that is eyeless, colorless and faintly electric blue in life, according to a UAH press release from July.  

The new genus, formally known as Demogorgonichthys arcanus, but aptly dubbed “demon cavefish,” was discovered in Bobcat Cave — under the US Army’s Redstone Arsenal in Huntsville.

Demogorgonichthys references the mythological underworld figure “Demogorgon” known through the game “Dungeons & Dragons” and the Netflix show “Stranger Things” — while arcanus means “hidden” or “secret,” according to UAH.

Combined, the scientific name reflects the cryptic species’ underground habitat and decades-long concealment in the cave system. 

“This is one of the last places we’d have bet on it,” the study’s lead author Dr. Matthew L. Niemiller said. 

“Finding an entirely unknown, new genus of freshwater fish in eastern North America today is a little like finding a new kind of big cat,” he quipped. 

“The group is so well known, we thought the big surprises were behind us.”

The UAH researchers, as part of the University of Alabama System, published their findings in Scientific Reports in July in collaboration with researchers from three other regional universities.

Shockingly, the pool in which the “demon cavefish” was discovered, is home to “Southern Cavefish” — yet the two species are not close relatives. 

“This is the part I find most remarkable,” Niemiller says, adding that the two species “found its own separate way into the underground world and lost its eyes and pigment independently, millions of years apart.”

“It’s a vivid case of convergent evolution,” he said.

The Bobcat Cave system has been monitored “at least quarterly” for over 30 years.

“To have one turn up in a cave we’ve watched for three decades is a real reminder to stay curious. It was genuinely surprising,” Niemiller added. 

Redstone-Arsenal has been likened to Alabama’s own “Area 51” due to the secretive and highly secure nature of the Army base that handles critical defense and missile programs as well as classified aerospace projects.

As the new “demon cavefish” was only found in a single cave and its connected aquifer beneath the US Army base, researchers believe it is highly vulnerable to changes in hydrology and ground water quality.

While the restricted-access military base protects the cave system from “direct disturbance,” the cryptic species remains vulnerable to “threats originating at the surface, including contaminants, sediment and changing water conditions,” according to UAH.

Researchers determined the fish’s underground habitat has been contaminated, likely from residue from chemical weapons from the military base. 

“Trace metals, including cadmium, chromium, and lead, have been detected at elevated concentrations in water samples from Bobcat Cave over the past two decades,” Niemiller’s team wrote in their scientific report.

Despite the miraculous yet cryptic discovery, Niemiller said his team’s work is far from over.

“The ‘Demon Cavefish’ is a reminder that our inventories are far from finished, even in well-explored places,” he said.