ORNL researcher helps discover new species of cave snail

A researcher at Oak Ridge National Laboratory helped discover a small cave snail.

The new snail species has been named the Tennessee cavesnail, or Antrorbis tennesseensis. Its name honors the state where it was found and the fact that several researchers involved in its discovery are affiliated with the University of Tennessee. A paper describing and naming the species was published in December.

The snail, which is less than two millimeters long, was found in two caves in Roane County a few miles south of the Oak Ridge Reservation. The reservation includes ORNL and parts of the city of Oak Ridge.

The snail is found on or under rocks far inside the caves, usually in streams that aren’t too muddy or silty, ORNL said. Researchers recommended that the species be listed as endangered.

The ORNL researcher is Evin Carter. He is a research associate and wildlife ecologist at ORNL, which is a U.S. Department of Energy laboratory. With only a handful of surveys completed so far, Carter has plans to survey the 40 or so other caves on the Oak Ridge Reservation, ORNL said.

Carter is a UT graduate and so are researcher Matthew Niemiller, a corresponding author who is now at the University of Alabama at Huntsville, and the study’s lead author, Nick Gladstone, whom Carter mentored during a post-master’s research experience at ORNL and who is now a doctoral student at Auburn University. Another researcher involved in the snail’s discovery was UT Professor Annette Engel.

The researchers found populations of the Tennessee cavesnail during several different biological inventories, but it took a few years to officially classify the species, ORNL said. The first snails were found in 2014, and more specimens were collected in 2018 and 2019. The researchers then had to confirm that these snails were indeed a new species, and describe and name them. The paper that described and named the species was published in December 2019.

Researchers confirmed populations of the Tennessee cavesnail in the two caves in Roane County a few miles south of the Oak Ridge Reservation. The snails found in 2014 came from one of these caves. The species was also possibly identified in a third cave in Knox County a few miles northeast of the Oak Ridge Reservation, but the researchers were not able to confirm that the snails there were the Tennessee cavesnail, ORNL said.

Carter, the ORNL research associate, is a conservation ecologist and longtime caver, the lab said.

“Caves are sort of the out-of-sight, out-of-mind environments that receive little attention, even from biologists, but there’s a lot of undiscovered diversity in caves,” Carter said in a story published by ORNL.

There are more than 1,100 species identified in caves, the lab said.

“Crawling underground to find new ones is often muddy and always tough—requiring researchers to squeeze through tight spaces, scramble over boulders, rappel into pits, and sometime even wade, swim, and snorkel through underground stream networks,” the ORNL story said. “Looking for snail microspecies such as A. Tennesseenis, which measures in smaller than the tip of a crayon, takes a keen eye.”

“Basically, we’re flipping rocks and looking for smooth pieces of sand,” Carter said.

Researchers pick up the minute mollusks (snails are mollusks) using delicate tools—sometimes a small paintbrush or a pipette—and store them in vials. From there, the process of sifting through specimens often moves at a snail’s pace, ORNL said. Taking the necessary steps to classify them can take years.

But there’s a purpose to the hard work, the lab said.

“From a conservation perspective…if we can’t say that this species is here, we can’t effectively conserve it in the long term,” Carter said. “It’s challenging to spur conservation action for animals that are not yet officially described.”

The researchers recommended the Tennessee cavesnail be listed as endangered based on standard vulnerability assessments. The proposed designation could help conservation organizations, and state and federal agencies, help protect the snail, ORNL said.

Snails and mollusks are among the most endangered groups because they can be sensitive to sediment levels and often have very specific habitats, Carter said in the story published by ORNL. That means human manipulation of the environment—such as damming, culverts, and construction and agricultural practices that change water flow or release silt into rivers and streams—can have a major impact. Species that only live in caves—relatively stable environments where weather and light changes are minimal to nonexistent—can be especially vulnerable to these changes that come from the surface.

“Snails’ sensitivity to habitat changes means that any dramatic changes to snail abundance or behavior could signal a larger environmental problem,” ORNL said. “Additionally, in very low-energy systems like caves, even the smallest lifeforms may play important ecological roles, perhaps ensuring the survival of more well-known cave species such as bats and salamanders.”

The results of the work were published in a paper titled, “A new species of stygobitic snail in the genus Antrorbis Hershler & Thompson, 1990 (Gastropoda, Cochliopidae) from the Appalachian Valley and Ridge of eastern Tennessee, USA,” in the journal ZooKeys.

Authors included Gladstone, Carter, Engel, and Niemiller, and Kathryn E. Perez of the University of Texas Rio Grande Valley, Evelyn B. Pieper of the University of Tennessee, Katherine Dooley of the University of Alabama at Huntsville, and Nathaniel F. Shoobs of Drexel University.

The Cave Conservancy Foundation supported the research. Cave work and wildlife surveys on the Oak Ridge Reservation were also supported by DOE Reservation Management through the Wildlife Management Task.

ORNL is managed by UT-Battelle for DOE’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States.