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Biological Survey Underway at Natural Bridge Caverns

Published Wednesday, August 10, 2022 2:00pm

Continued exploration of Natural Bridge Caverns yields new biological finds of cave adapted species.

New Braunfels, TX  August 5, 2022   -- A new expedition is set for August 6th in Natural Bridge Caverns, and this time the effort is focused on developing a better understanding of this unique environment. A biological inventory, conducted by Texas based Zara Environmental, began earlier in 2022 so far has produced a picture of a thriving ecosystem in the cave and discovered six new species not found in the caverns previously. The search is now on to find more in a newly discovered hidden stream of water deep below the surface and follow it to where no person has ever been.

Among the thriving cave adapted species the researchers have found so far are non-endangered top predators including Chinquipellobunus madlae, an orange cave-adapted harvestman, as well as tiny snails that live in the groundwater deep within the cave and are the size of sand grains. [Video and photos here]

The six new species recorded for the cavern and a few species collected required taxonomic work under the microscope to identify. Two of the new species to Natural Bridge Caverns were groundwater crustaceans; a Cirolanid isopod and an amphipod (Stygobromus russelli) that looks like a small shrimp without eyes and pigment. Hundreds of snails were collected and sent to Dr. Kathryn Perez at U.T. Rio Grande Valley, an expert in aquatic snails. Dr Perez identified a groundwater snail, Phreatodrobia plana, collected amongst mostly freshwater snails, Phreatodrobia nugax. The team at Natural Bridge Caverns plans to showcase these new species, as well as others previously found in the cavern system, in a new educational exhibit scheduled to open in 2023.

“Our guests are fascinated by the adaptations necessary for animals of all types to live in a cave,” said Brad Wuest, president of Natural Bridge Caverns. “As stewards of this cavern system we know the more we understand about the species that inhabit the cave, the better we’re able to track our efforts in safeguarding the environment all around it. A biological sampling is one step in that effort. As cave explorers we’re also fascinated by life in these beautiful, dark places.”

In the world of cavern dwelling species, the cave adapted Chinquepellobunus in Natural Bridge Caverns is the equivalent of a grizzly among the tiny creatures of the cave world. It looks to us like a thin-legged spider with a body smaller than the end of a Q-tip, but when scientists look closely, they can see arm-like mandibles that have a row of long spiny teeth. Chinquepellobunus is not a spider at all - it is a different group of arachnids altogether. This is one of the cave-adapted species guests could be lucky enough to see during a public tour of the caverns. The Cicurina varians and Araneae are two types of spiders found in the cavern along with a common cave insect, the Texoreddellia, which is a subterranean silverfish.  In the water within the cave the team found two types of springtails:  Collembola and Symphypleona. Biologists also snapped a photo of an eyeless amphipod that is yet to be identified.

“It’s important to understand the biodiversity of the cave system because a healthy cave means healthy groundwater,” noted Liza Colucci, project manager and ecologist from Zara Environmental. On August 6th, the team plans on pushing into newly discovered areas to determine if identical species to those found in earlier expeditions exist there as well and also to see if additional aquatic species exist in the new areas.  The team is also considering conducting a dye trace to confirm the water flow throughout the cave. Surveys indicate that the newly discovered Popcorn Pit River is upstream of the River Styx and other locations, but a dye trace will prove it definitively.

For more information about adventure caving tours, walkable public tours, and above ground adventures at Natural Bridge Caverns, visit [Video and photos here]

About Natural Bridge Caverns:

26495 Natural Bridge Caverns Rd, Natural Bridge Caverns, TX 78266  210-651-6101  

Natural Bridge Caverns is one of the world’s premier show caverns. Discovered in 1960 by local cavers, this family owned and operated natural wonder is the largest cavern in Texas. In addition to multiple tour experiences through two distinct caverns, the property features above-ground adventures of a different kind including a ropes course, zip rails, a 5,000 square foot outdoor maze, and even an interactive “gem panning” activity. More of the cavern system itself is still being discovered; the Wuest family along with their caving team are still actively exploring new areas in the massive cavern. Natural Bridge Caverns is a designated State Historical Site, National Natural Landmark, and is listed on the National Register of Historic Places.   


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