Cave dragons exist - and saving them could be key to protecting drinking water (2023)

2015,Gregor Aljancicalmost died hunting cave dragons.

the head ofTular Cave Laboratory, operated by the Slovenian Society for Cave Biology, was diving in the underground passages of Planina Cave when it became trapped in a small air pocket. Half a mile down, running out of oxygen, he did his best to guess which direction he was heading to safety. By a stroke of luck, he landed in another air pocket. Nearly four hours later, he found his colleagues - just before rescuers arrived.

"The only reason he's alive now is because he found an air pocket in one of the crevices that kept him alive, and he slowly came back," he says.Stanley meetings, a biology professor at Hartwick College in upstate New York who studied cave dragons with Aljančič in the Balkans. "It is only by the grace of Proteus - the great Olm in the sky - that he lives today."

The blind cave dragon, as it is known, has long been popular with biologists for its unprecedented strangeness. These snake-like amphibians have small limbs, horn-like gills recessed from their long snouts, and translucent pinkish-white skin that resembles human flesh. Up to 30 centimeters long, they are considered the largest cave animal in the world. They live up to 70 years, which they spend entirely underground in the Dinaric Alps, which encompass parts of Slovenia, Italy, Croatia and Herzegovina.

"I'm fascinated by their extraordinary adaptation to the extreme cave environment," she says.gregorbalazs, a doctoral student in cave biology at Eötvös Loránd University in Budapest, who studies the caves where these dragons live. "And they're baby dragons, for God's sake."

Well, not exactly. In the past, locals believed that on the rare occasion that floods would bring someone to the surface, they were baby dragons - hence the nickname. One of the creature's other nicknames, Proteus, comes from an ancient Greek god of the sea who had the ability to change shape. And while the origins of the German name (olm) are uncertain, the Slovenian name (človeška ribica) roughly translates to "man-fish".

One would think that the obscure habitats of these legendary creatures would place them safely beyond the reach of human destruction. But their aquatic ecosystems collect runoff from whatever leaves the surface, meaning they still face habitat destruction due to development and hydroelectric projects that drain and divert groundwater supplies. Today, they face increasing pollution from runoff from farms, not to mention former chemical waste plants.

"Karst is one of the most endangered landscapes on Earth," says Aljančič, referring to the limestone landscapes riddled with sinkholes and caves where cave dragons live. In addition, a greater focus on Proteus conservation could also save water for Slovenians and neighboring countries, he adds. After all, the same water that flows into the world of olmen is the source of drinking water for 96% of Slovenians.

"If they pollute the water and kill these guys, it will be the biggest disaster ever," Sessions says.

Furthermore, Proteusa is just the top of a diverse underground food chain that can also be killed by pollution. “The caves in Slovenia are like rainforests. They are biodiversity hotspots in terms of the number of species,” says Sessions. "And the species are cave-adapted, so they are very, very strange."

To save a dragon, you must first find it. This is quite a challenge when your subject lives in a vast underground labyrinth of limestone passageways. To facilitate the search for dragons and improve scientists' ability to locate them, Aljančič and his colleagues are now using new techniques to collect DNA samples from the environment thatlocate tiny traces of genetic materialin the water to discover where the creature is hiding without having to go cave diving.

Olms' subterranean isolation has protected them from some of the greatest threats to amphibians in recent decades, such as human interference.of Climate Changeand invasiveMushroom-illnesses. But now the problems of the world above seem to have reached the world below. “We need to know more about Proteus and its habitat if we want to keep both intact in the future,” says Aljančič. "New approaches to surveillance techniques such as eDNA will not only reduce the need for risky caving or cave diving, but will also increase the quality of data collected in the wild."

Aljančič and his colleagues recently published one of the largestSurveyof cave dragons, for which they took water downstream from hidden cave systems to identify a series of new populations in Slovenia, Bosnia and Herzegovina and the first known ones in Montenegro. To do this, they used a sophisticated DNA technique that allows them to locate Proteus.Strands of DNA mixed with countless other genetic materials in the water. The technique also allowed them to discover Proteus, with a rarer black color, in southern Slovenia, doubling the known range of that cultivar.

Despite the threats they face, Proteus numbers can be enormous. Sessions tells a story about biologists exploring some of the farthest corners of the massif.Postojna-Höhle– a famous Slovenian tourist attraction – when they came across a huge underground cavern. “They found this big lake with echoing dripping water; The only thing missing was Gollum,” he says. The bottom of the lake was completely white, but as they got closer, the color suddenly dissipated.

"It turns out that the bottom of the lake was completely covered in olmen," says Sessions. "It gives you an idea of ​​how many of these things are out there."

Cave dragons roost in a complex cave food chain that includes shrimp, spiders, arthropods, woodlouse-type creatures, and more. Predatory dragons will eat almost anything they can fit in their mouths, but that doesn't mean they always have an appetite, in part due to a very low metabolism; Sessions says that some researchers have recently uncovered evidence that an individual in captivity has not eaten in a decade.

Sessions, who was not involved in Aljančič's recent study, says the new eDNA technique is a good way to detect Proteus. "This study takes a truly non-invasive and non-destructive approach, just looking at environmental water for fingerprint DNA," he says. The technique is particularly useful for finding genetic traces of Proteus in water, adds Balázs. It can come in handy in situations where murky water makes visibility difficult for divers like him. "If you're just banging your head on rocks and you can't find your way, it's not fun," he says. "And you don't see the animals either."

"Science is all about the how and the why," Balázs continued in a follow-up email. “We need to know how strong the population is. Are you healthy? Can we find the youth? ... We have no information about what they do in the wild in real life. It's really hard to watch.”

Will Aljančič and his team's advances in using environmental DNA to detect discoveries soon make cave diving obsolete? Unlikely, says Balázs, who was involved in the appointmentlearnof animals in 2015. Finally, eDNA is a useful and accessible tool, but biologists have only a vague idea of ​​where dragons live. Divers still have to hunt them down.

To do this, Balázs spent nearly 15 years squeezing through nearly 50 karst cracks and underwater tunnels, chimneys and caves in what he calls Bosnia and Herzegovina's "labyrinth of constraints". While cave diving can be difficult just for exploration purposes, he says, cave diving to look for Proteusis is even more difficult, as the snake-like creatures can take refuge in small cracks in the rock that are difficult for humans to access.

However, no matter how much we find out about them, it's likely that cave dragons still fill us with mystery and wonder. "They don't do anything," says Balázs. "They live in strange places and haven't moved in years."