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Few people know of its existence, but Bobcat Cave in Huntsville, Alabama, is one of the most unique ecosystems in the United States. With a mapped length of nearly 1,490 feet, the underground limestone network is only passable through low, water-filled tunnels and slippery mud paths. Despite these claustrophobic confines, researchers have spent nearly 40 years regularly monitoring Bobcat Cave for its rare resident, the Alabama cave shrimp (Palaemonias alabamae). This small, extremely endangered species of nearly translucent freshwater crustacean is only documented in cave systems stretching between Alabama and Tennessee, making it invaluable to conservationists.
But after recent expeditions to Bobcat Cave, researchers now say the little shrimp lives alongside an unexpected neighbor. According to his recent study published in the journal Scientific ReportsBiologists at Auburn University discovered a pale, eyeless fish that measured less than two inches long. Although tiny, the new species now has an imposing name: the cave demon fish (Demogorgonichthys arcana). What’s more, the subterranean dweller is so genetically distinct that it has earned its own genus, and that probably makes it one of the rarest fish in the world.
“More often than not, when we discover new species, we find differences within organisms that we already knew existed,” Jonathan Armbruster, co-author of the study and curator of fish at the Auburn University Museum of Natural History, said in a statement. “This was different. It was a new discovery that hadn’t been seen before and it’s really rare.”
The cave devilfish is related to the more common southern cavefish species (Subterranean Typhlichthys), as well as the harder-to-find Alabama cavefish (Speoplatyrhinus poulsoni). However, it has some key differences. Aside from its unique snout, body shape and lack of coloration, the cave devilfish lacks part of a key gene related to light sensitivity.
“The southern cavefish clearly has some type of response to light. With this fish, we don’t see that,” Armbruster said. “Part of the rhodopsin gene is missing, so it is no longer functional.”
The fearsome scientific name of the cave demon fish may remind us of the monstrous Demogorgon from the hit Netflix series. stranger thingsbut the reference is actually even older. Study co-author and University of Alabama biologist Pamela Hart has long maintained a running list of mythological subterranean creatures as possible inspirations for future species names. The Demogorgon’s origins date back not to Hawkins, Indiana, in the 1980s, but to ancient Greece. The 17th century poet John Milton even described it in lost paradise.
Its specific name, “arcane“, is Latin for “hidden” or “secret,” which is appropriate. So far, researchers have only seen about 20 cave demon fish at a time.
“It may have been living in the aquifer and recently ascended,” Armbruster said. “Or it may have been there before and we just never saw it.”
Like the Alabama cave shrimp, biologists are using the cave devilfish as another example of the importance of strengthening conservation efforts in these delicate and unique ecosystems.
“It may have been living in the aquifer and recently ascended,” Armbruster explained. “Or it may have been there before and we just never saw it.”
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