Inhabiting a single area around Barton Springs in Texas, the Barton Spring Salamander is a tiny lungless freshwater salamander. It is listed as Endangered by the International Union for Conservation of Nature, and was not scientifically described until 1993.
The Barton Spring Salamander, like many other salamanders, is very private and keeps itself hidden from observation. The egg gestation period is known to be one year, as is the maturation time of the larval salamander. There is evidence that breeding is not a cyclical event but instead takes place all year, but no deposited eggs have been observed in the wild. Since the Barton Spring Salamanders only inhabit a pair of connected springs, it is believed that the laid eggs are contained in a porous underground aquifer where they cannot be seen. Captive females deposit their eggs in long clusters, surrounded by protective jelly, but no captive eggs have ever developed to sexual maturity. This makes it hard to study and understand their breeding habits, and since captive-breeding programs have not been successful, it is likely that they can only survive in their single, evolved habitat, making the conservation of the Barton Spring and its aquifer of vital importance if the Barton Spring Salamander is to survive.