Central Texas is home to three newly discovered salamanders, offers new research. But encountering these fresh amphibians, it's not as easy as strolling through the woods surrounding Austin. These salamanders – and more than a dozen close relatives – live deep underground in a network of flooded canals that pass through porous rock limestone rocks.
And there they may be more at risk of extinction than previously thought.
The Salamanders are guided in a subdivision of the hidden, stiff waterways of the Edwards-Triniti aquifer, which extends tens of thousands of square miles across the western center of Texas, far below the roasted surface. Despite the poverty of nutrients, the aquifer is one of the most biologically diverse ecosystems of groundwater on the planet. Some of its inhabitants are descendants of the ocean species that remained after this area was under the shallow sea about 100 million years ago, according to Tom Dewitt, lead author of the study and environmental scientist with water conservation in Austin. Department.
Others, like the Salamanders, have moved away quite recently and have turned into specialized cave creatures – pale-eyeless, with flattened heads and thin limbs. Some species are found only in certain places, like Salamander Barton Springs, and are protected by federal territories.
To better understand the evolutionary history of these salamander, how they are today, and how many species exist, Dewitt and his colleagues looked at the genealogy of salamanders. They took more than three hundred genetic samples of fourteen known types of salamanders of groundwater through nearly 100 spring areas along the aquifer. By comparing thousands of genes between individuals, the team could determine where in the aquifer live some species.
Their results, published today in the writings of the National Academy of Sciences, indicate that the genetic divisions among the salamanders reflect a geographic series of isolated underground fingers of the aquifer. Salamanders do the water development, which shows that the physical, hydrogeological features of the aquifer contributed to the formation of a large number of branches on the generic salamanders.
Comparing the genetics of salamanders through the aquifer and drawing boundaries between species, the team has identified the existence of three completely uncertain species, genetically different from any known close relatives. One of them is the salt color found only in the tiny part of the Austin Peedernales River, which researchers consider to be so rare and limited in the habitat that they are critically dangerous.
The researchers also found that the Georgetown Salamander described earlier is already neglected, limited to an even smaller area than originally thought.
Now that new species have been identified, says Dewitt, the next step is the formal name and description of what the team is doing right now. Identifying the existence of these species is crucial for their long-term survival, especially in the light of urbanization, which threatens the quality of the water of the aquifer.
"Everything that makes karst aquifers with such large water resources – fast feeding, high porosity and permeability – makes them particularly vulnerable to pollution," Dewitt said. "A rupture of the pipeline or bottling can be catastrophic for the species of narrow endemic aquifers."
There is also the effect of people sucking more water from the aquifer than can be replenished, which leads to a drop in water level. Dewitt noted that some areas of the aquifer of the Trinity saw a water level drop of more than 1,000 feet since the 1950s.
"The fact that water is gone is not going back," he said. "For living organisms of aquifers, such as salamanders, it is a loss of habitat that you do not see."
Despite the fact that salamanders are only large in size, salamanders are the largest predators in the ecosystem of the aquifer, which means that humans allow the decay of these paleoes in their own threat. They are likely to be critical to maintaining the health and water quality of these sensitive aquatic systems, and their loss may endanger the key source of the region's water in a way we do not yet understand.
"We do not know enough about how this community functions, to know exactly what will happen if they die," said Esther. "But this is how to pick up parts from a complex car: some parts can be removed, and the car will still work, but if you do not fully understand how the car works, it's a bad idea to remove the parts at random and hope that nothing will be .
Jake Buller is a scientific writer who lives on the Olympic Peninsula of Washington with the worship of the strange, wild and unexpected Tree of Life. Follow him Twitter or in his blog.