Friday, September 18, 2020
  Research, Science & Technology

By Amanda Taylor

RIO GRANDE VALLEY, TEXAS – Deep within the caves and underground aquifers in Central Texas, an amazing discovery was waiting to be found.    

It was a tiny snail, caught in a net by Pete Diaz and Randy Gibson of the U.S. Fish & Wildlife Service, during studies of other aquifer animals including endangered salamanders, which eat the tiny snails.    

Once Diaz and Gibson realized they had never seen this type of snail before, they sent samples to snail expert Dr. Kathryn Perez, assistant professor of Biology at UTRGV, for assessment.    

Perez and Dominique Alvear, then a UTRGV Biology undergraduate student, looked at the samples and realized they had a new species in hand.    

“Our colleagues do extensive collections work and we had the required expertise to recognize and describe something new,” Perez said. “These snails are really tiny – like a grain of sand. They live in aquifers underground, so they’re entirely subterranean and found within the Edwards aquifer, which is the main water source for New Braunfels and San Antonio – that whole metro area.”   

The tiny snail now has a name – scientifically known as Phreatodrobia spica. But it’s also called the “spiky cavesnail,” so dubbed by Alvear.  

“We call him ‘little spiky’ because of all the unique little spikes on his shell,” Alvear said. “I was sifting through different samples and started identifying all these species within this one sample that were already known. Then, sure enough, this weird-looking thing comes up.” 

Alvear said that she immediately sent the photo of the odd snail to Perez, who was out of town. After deliberation with colleagues, no one knew what the snail could be.    

“I quickly found out that he wasn’t pictured in any literature. We ran some DNA on it and, sure enough, he was distinct from every other species that was quickly able to be identified,” Alvear said. “He’s genetically different, so that means he’s not a subspecies or anything else. I was really excited about the discovery – I still am.”   

Perez and Alvear’s research has been published by Zootaxa, an international journal that focuses on rapid publications of animal taxonomy and new species or reorganization of species.    

This is the second new species of snail identified through Perez’s research with her students. The first snail was Praticolella salina – a salt-loving snail found at South Padre Island and in coastal Cameron County.    

The research on “little spiky” was submitted for publication in 2019, but revisions and updates were necessary along the way for the final release. Alvear was an undergraduate when she had two other publications released on related research.    

“This research is from a whole series of projects that we’re working on about snails in Central Texas,” Perez said. “Most undergraduates don’t have a publication released, much less three, so having three publications coming out of your undergrad into grad school is great going forward, with whatever career she prefers.”    

Alvear, a recent UTRGV graduate, supported her research through two UTRGV Engaged Scholars grants. She currently is pursuing her Ph.D. at Texas A&M within the Interdisciplinary Genetics Program.   

While most people would not have even realized this tiny spiky snail existed, both Perez and Alvear realize the importance of finding new species.    

“Ecologically, it’s really important that we know what’s happening in our groundwater, as we rely on it every day,” Alvear said.    

“They eat the bacterial mats that grow underground, so all the bacteria and flora produced underground - these snails feed on it and help control all of that, which in turn affects all the springs and streams aboveground. These snails are helping keep all this water healthy.”  

spiky cavesnail
Samples of the spiky cavesnail, which have been identified as a new species. (UTRGV Photo by Paul Chouy)


The University of Texas Rio Grande Valley (UTRGV) was created by the Texas Legislature in 2013 as the first major public university of the 21st century in Texas. This transformative initiative provided the opportunity to expand educational opportunities in the Rio Grande Valley, including a new School of Medicine, and made it possible for residents of the region to benefit from the Permanent University Fund – a public endowment contributing support to the University of Texas System and other institutions.

UTRGV has campuses and off-campus research and teaching sites throughout the Rio Grande Valley including in Boca Chica Beach, Brownsville (formerly The University of Texas at Brownsville campus), Edinburg (formerly The University of Texas-Pan American campus), Harlingen, McAllen, Port Isabel, Rio Grande City, and South Padre Island. UTRGV, a comprehensive academic institution, enrolled its first class in the fall of 2015, and the School of Medicine welcomed its first class in the summer of 2016.