Central Texas is home to three newly identified salamanders suggesting new research. But encountering these fresh amphibious faces is not as simple as taking a walk through the woodlands that cuts Austin. These salamanders – and more than a dozen close relatives – live deep underground in a network of flooded canals running through the Lone Star state's porous limestone grounds.
And there they may be more vulnerable to extinction than previously believed.
The salamanders navigate part of the hidden, stubborn waterways of the Edwards-Trinity aquifer which stretches for tens of thousands of miles miles west-west Texas, far below the sun-drenched surface. In spite of being poor in nutrients, the aquarium is among the most biodiverse groundwater ecosystems on the planet. Some of its inhabitants are descendants of ocean-dwelling species left behind as the area was below a shallow sea some 100 million years ago, according to Tom Devitt, study director and an environmental researcher with the city of Austin's Watershed Protection Department.
Others, like the salamanders, recently moved in and evolved into specialized cavities – pale and eyeless, with flat-haired heads and strung limbs. Some species are found only in some places, such as Barton Springs Salamander, and are federally protected.
To better understand the evolutionary history of these salamanders, how they are rushing today, and how many species there are, Devitt and his colleagues saw salamander's genetics. They took more than three hundred genetic samples of the fourteen known species of groundwater salamander across nearly one hundred springfields along the aquarium. By comparing thousands of genes between individuals, the team could determine where in particular species in aquifer lived.
Their results, published today in the Proceedings of the National Academy of Sciences, show that the genetic divisions between the salamander populations mirror the geographic series of isolated, subterranean fingers in the aquarium. Where the water fork, the salamander species, which shows that the physical, hydrogeological features of the aquarium were instrumental in generating countless twigs on the salamander family tree.
When comparing salamanders' genetics across the aquarium and drawing species boundaries, the team discovered the existence of three completely unspecified species, genetically separated from any known near-fetuses. One of these is a straw-colored critter found only in a small area of the Pedernales River near Austin, the researchers consider so rare and limited in habitats that it is critically endangered.
The researchers also found that the previously described Georgetown salamander, already considered indefinite, is limited to an even smaller area than originally thought.
Now that the new species have been identified, Devitt says, the next step is formal naming and description of them, which the team is currently doing. Revealing the existence of these species is crucial for their long-term survival, especially in the light of urbanization that threatens the water quality of the aquatic environment.
"Everything that makes karst aquifer so great water resources, fast recharging, high porosity and permeability – makes them particularly vulnerable to pollution," Devitt said. "A pipeline break or spill can be catastrophic for narrow endemic aquatic species."
There is also the effect of people sucking more water out of the aquarium than it can be refilled, causing the water table to fall. Devitt noted that some areas of the Trinity Aquifer have seen their water drop of over 1,000 feet since the 1950s.
"That water is gone, it doesn't come back," he said. "For aquaculture living organisms such as salamanders, it's habitat loss you can't see."
Despite being only the thumb size, salamanders are top predators in aquatic ecosystem, which means that humans allow these palid wrigglers' death themselves danger. They are probably crucial to maintaining the health and water quality of these sensitive aquatic systems, and their losses can compromise the region's main water source in ways we do not yet understand.
"We do not know enough about how this community functions to know exactly what would happen if they expire," says evolutionary biologist and senior researcher, David Hillis, Earther. "But it's like taking parts from a complex car: some parts you can take off and the car is still running, but if you don't fully understand how the car works, it's a bad idea to randomly remove parts and hope that nothing will happen. "
Jake Buehler is a writer of science living in Washington's Olympic Peninsula with a worship of the Tree of Life is strange, wild and unhealthy. Follow him on Twitter or on his blog.