Head to head
Comal Springs Salamander vs San Marcos Salamander
A Comal Springs salamander and a San Marcos salamander both illustrate just how narrowly a species can be defined by geography, each restricted entirely to a single named spring system barely a short drive apart in central Texas.
| Comal Springs Salamander | San Marcos Salamander | |
|---|---|---|
| Scientific name | Eurycea sp. | Eurycea nana |
| Confined to | Comal Springs system | San Marcos Springs |
| Notable trait | Likely extends deep into aquifer passages | One of the smallest Eurycea species |
| Microhabitat | Spring outflow and aquifer | Aquatic vegetation and gravel |
| Life stage | Paedomorphic, gilled for life | Paedomorphic, gilled for life |
| Shared water source | Edwards Aquifer | Edwards Aquifer |
| Location | New Braunfels, Texas | Hays County, Texas |
| Conservation status | Endangered | Vulnerable |
Comal Springs Salamander vs San Marcos Salamander: common questions
Are the Comal Springs salamander and San Marcos salamander the same species?
No, though both are Edwards Aquifer-dependent Eurycea salamanders confined to a single Texas spring system apiece, the Comal Springs salamander is restricted to the Comal Springs system in New Braunfels while the San Marcos salamander is confined to the separate headwater springs of the San Marcos River, and the two are recognised as genuinely distinct species.
Why are both of these salamanders so vulnerable?
Both species depend entirely on a single spring system for survival, meaning any significant reduction in spring flow from drought or groundwater pumping from the shared Edwards Aquifer could threaten each species' entire population at once, since neither has any alternative habitat to retreat to elsewhere.
Do both salamanders keep their gills as adults?
Yes, both the Comal Springs salamander and the San Marcos salamander are paedomorphic, retaining external gills and remaining fully aquatic even as sexually mature adults, never developing into a lunged, terrestrial form the way many other salamander species eventually do.