The Search for the Lost Salamander
A pale, eyeless, possibly cannibalistic amphibian swims silently beneath our feet. Or at least, scientists hope it does.
By Eva Frederick

Deep beneath the surface of the Hill Country, where the Texas sun never reaches, fantastical eyeless creatures swim in the dark, cold water of the aquifers.
“They live in a totally different universe,” says Andy Gluesenkamp, director of conservation at San Antonio Zoo's Center for Conservation and Research. “That ecosystem is as different from where we are existing right now as the deep sea — and yet it could be 50 feet away from you. We have very, very few portals where our world and their world intersect.”
It's at one of these portals that I meet Gluesenkamp on a warm April morning. Feeding into to a reed-filled cistern at the Aldridge Nursery south of San Antonio, a pipe connects us surface-dwellers with the dark mysteries of the Edwards Aquifer and the creatures that inhabit it.
Gluesenkamp, formerly the Texas state herpetologist, frequents such places in search of several different subterranean species. One, in particular, is special to him: the Blanco blind salamander (Eurycea robusta).

“It's my white whale,” Gluesenkamp says, referencing the sought-after creature in Herman Melville's Moby Dick. “It's this mythological thing. There's only one specimen [known to science]. It's bigger than all the others; it's exceptional in every way. And I've been chasing that thing, really, since 1998.”
The salamanders were discovered nearly 80 years ago, in 1951, when workers excavating a water source in the bed of the Blanco River near San Marcos pulled out four slimy, pale creatures that no one recognized. According to the story, a passing bird snapped up two of them; one was lost; the remaining one was transported to the University of Texas at Austin, where it was designated a new species.

Since then, the river has changed course and no more salamanders have been seen. That's not so surprising, since the creatures live far below the places people conduct their lives. But it means that the salamander is a lost species, defined as a species not recorded by scientists in at least the last 10 years.
If the salamanders are, in fact, still down there, being classified as “lost” hurts their chances at receiving protective conservation measures. In 2022 the U.S. Fish and Wildlife Service decided against listing the species as threatened or endangered, justifying their decision by saying the salamander could have been just a really big specimen of another eyeless (and cannibalistic) species, the Texas blind salamander, or else it could be extinct.
But Gluesenkamp has hope for the Blanco blind salamander. And over the past few years, he's embarked on an ambitious search to find them. His journey has taken him to the frontiers of genetic analysis and into caves far beneath the Texas Hill Country. The salamander still eludes him, but perhaps not for long, thanks to cutting-edge molecular techniques.
Traces of Life
The plight of the missing salamander has drawn attention from many places, including Re:wild, a Texas-based conservation group with the actor Leonardo DiCaprio as a founding board member. In 2017, Re:wild set a goal to find the “most wanted” of the thousands of lost species across the globe. The Blanco blind salamander made the cut, and Re:wild is providing financial support for Gluesenkamp's mission.
“The [salamander] was obviously really, really fascinating because it's subterranean,” says Christina Biggs, a lost species officer with Re:wild. “It occurs in aquifers that are deep underground. They're not places that people can get to or access.”
The salamander is an example of a troglobite, or cave dwelling species that has adapted to life underground. These creatures are often pale pink or white, as they do not need pigment to camouflage or protect them from the sun. They also often lack eyes, as sight is not a useful sense in the underground darkness.
The salamander's hard-to-reach habitat was one reason Re:wild chose to highlight the creature on their most wanted list. “Some of the searches are as easy as going for a walk with binoculars and a field guide and just trying to spot something visually,” Biggs says. “Some things like deep sea research involves ships and ROVs and things like that. This one is particularly difficult, because how do you look under the surface of the Earth?”
How, indeed.
Biggs and Gluesenkamp weren't the only ones wondering how to look for these creatures. Gluesenkamp found a searching partner in Dean Hendrickson, another biologist fascinated by the denizens of the deep aquifers. Hendrickson, a fish biologist and curator of the University of Texas' Ichthyology Collections, is looking for a catfish called the Texas blindcat, Satan eurystomus. Hendrickson likes to call it simply “Satan,” which adds a little more intrigue to his fish-finding endeavors.

Like the salamander, these creatures have not been spotted in the wild in decades — since 1984. Because of the difficulty of reaching their habitats, Hendrickson and other researchers don't know if the fish are still out there, let alone basic information such as its population or range. If it is still swimming around, these unknowns hinder the fish from gaining any protections it might be eligible for under the Endangered Species Act.
For years, Hendrickson had been mulling over how to best study the catfish. Because these creatures, like the salamanders, live in deep reaches of the earth, it wasn't realistic to go digging around for them on people's land.
And then Gluesenkamp and Hendrickson landed on the perfect method: a relatively new technique of testing for environmental DNA, or eDNA. When an organism such as a salamander — or even a person — swims around, it leaves traces of itself behind. A few skin cells, a hair, a little bit of saliva — and all these things might contain DNA.

Thanks to modern technology, researchers can now detect these tiny traces of life through genetic testing and identify what type of organism they belong to. “When eDNA started to develop, it was like, bingo,” Hendrickson says. “This could easily tell us where those things are.”
In the case of the Blanco blind salamander, using the eDNA method is a little trickier; the one existing specimen is so old that it does not have any usable DNA, so it's impossible to know exactly what sequences to look for. But because it's likely a relative of the Texas blind salamander, the scientists can test for related genetic material. If DNA similar to that of the Texas blind salamander is detected, they could expand their search in that area to zero in on the creature shedding the DNA.

Can We Check your Well?
And so, with DNA sampling equipment in hand, Gluesenkamp and Hendrickson began their search in 2022. “We've been sampling just about wherever we can,” Gluesenkamp says. The scientists hope to focus their search on wells in the Texas Hill Country, where conditions are similar to the place by the Blanco River that the salamanders were first found.
Most of that land is privately owned, which means they're embarking on endless hours of calling landowners and asking for permission to take samples from their wells. “You don't have a lot of friends when you call people up to talk to them about salamanders,” Gluesenkamp laments. “These things are controversial critters,” he adds.
Controversial, because some landowners may worry that the potential discovery of a rare species on or below their land might lead to cumbersome paperwork and restrictions on how they can use their property.
That's not true, though, Gluesenkamp says. “That response is natural, but comes out of a void of information that's largely been filled by hearsay and negative things,” he says.
In fact, the discovery of a rare species can be a boon for landowners, offering opportunities for state or other funding for improvements to their property. Gluesenkamp and Hendrickson hope to build relationships with landowners, focusing their time on explaining the ins and outs of the projects and assuaging fears.
“I can't think of an example of my personal experience where the discovery of any of the threatened or endangered populations that I've encountered impacted the landowner in any negative way whatsoever,” Gluesenkamp says.
Getting this message out is important to the researchers.
“It's absolutely impossible to engage in effective conservation in Texas without partnerships with private property owners,” Gluesenkamp says. “Ninety-five percent of Texas is in private hands, so that right there says that you need to be a partner with private landowners. And that starts with that mutual trust and respect.”
Give Things a Chance
Since Gluesenkamp and Hendrickson started working on the project, there's been no sign of the missing salamander. But they're just getting started on the search, and they're feeling hopeful. So is Christina Biggs, of Re:wild. Finding the Blanco blind salamander and collecting information about its range could lead to protections that could help save this species.
“Some people ask me, ‘Should you be looking for things that are that rare? Is it just going to cause more problems by having them exposed to potential human exploitation?'” says Biggs. “But at Re:wild we really take the stance that you can't protect what you don't know. You have to gather as much data and knowledge as you can to be able to give things a chance.”
Why All the Fuss to Find the Blanco Blind Salamander?
Finding lost species benefits the creatures themselves by helping secure them the governmental protections afforded to threatened or endangered species. It also helps humans understand how the ecosystems around us work and how the creatures in them relate to each other and to us.
You Can Help the Search
Andy Gluesenkamp and Dean Hendrickson are looking for funding for their project; contact San Antonio Zoo's conservation department if you would like to donate. Or...do you have a well in the Texas Hill Country? Consider reaching out to see if your well might reach into potential habitat for the Blanco blind salamander and Texas blindcat.