CCAS Professor Helps Discover Salamander Species – The GW Hatchet


In 2008, David Beamer, a biology teacher at a community college in North Carolina, traveled the muddy swamps of the Gulf Coast plains to document a potentially new species of swamp salamander.

Now, 14 years later, Beamer co-authored a study published earlier this month with R. Alexander Pyron, an associate professor of biology at the Columbian College of Arts and Sciences, that used genetic data to introduce Desmognathus pascagoula as a new species of salamander . Pyron said Desmognathus pascagoula is the first of more than 20 new salamander species his team has discovered using genetic data from their fieldwork in the eastern United States, which they will publish in related articles.

Pyron said he’s been studying dusky salamanders in the eastern United States since 2010 and is now leading a team of researchers studying the animal. Biologists and researchers have historically mislabeled specimens of Desmognathus pascagoula as D. auriculatus or D. valentinei, other species of swamp dwellers, before Pyron’s team identified them as genetically and physically distinct.

Desmognathus pascagoula is smaller than other dusky salamanders, which range from just under an inch to about 7 inches long, according to the study, and are distinguished by their lateral white spots. Pyron said the brown color and small size of Desmognathus pascagoula make them difficult to find and identify in the muddy swamps where they live.

Pyron said he and his researchers would wade through swamps and search the mud under leaves and tree trunks for specimens of the new species to take genetic samples and compare their DNA to other salamanders. Pyron said it could take days or weeks to find two or three specimens.

“We’re waist-deep in just thick mud, and we’re basically just trying to rake through the mud and see if we can see a tiny little brown salamander squirming away,” Pyron said.

He said his research team received a grant from the National Science Foundation in 2017 to use DNA sequencing data to determine how potential new species differ from others, which helped in their discovery of new species.

Pyron said the new species could have gone undetected by researchers for years, noting they were found where scientists in the eastern United States had been exploring for centuries.

“The biodiversity of the planet is extremely underestimated and poorly understood,” he said.

Pyron said the discovery of new species reveals new information about their ecosystems and allows for a deeper understanding of a region’s ecology. He said alpha taxonomy – the discipline of discovering new species – is the “fundamental building block” for understanding evolution and ecology and striving for conservation.

Researchers consider the Gulf Coast Plain a biodiversity hotspot, a term coined to denote regions with significant amounts of unique species that are threatened by human activities. Pyron said classifying the region as a biodiversity hotspot, which researchers in the field decide based on criteria for the abundance of unique species and human impact on the region, would give the region’s distinctive plants and animals more public recognition bring.

“It’s underestimated when it comes to acknowledging the biodiversity that’s there and really acknowledging the distinctiveness of the region in terms of its flora and fauna,” he said.

Pyron said his team plans to continue publishing similar studies on the new species of dark salamanders they have identified before examining their evolution in depth.

According to Beamer, identifying new species and their habitats is key to conserving the habitats of endemic species — a plant or animal species native only to a specific area — like Desmognathus pascagoula.

“It’s easy to lose a species when its range is very small,” he said. “Hopefully there’s more interest now that we understand that this species is different and unique, and that we understand that it has a relatively small range.”

According to Beamer, identifying new species can also aid in the development of drugs and pharmaceuticals, which often derive ingredients from living organisms. He said salamanders have been the subject of studies aimed at finding a human application of their unique ability as the only vertebrates able to regrow complex tissue such as limbs and even their brains.

He said that better understanding of the coastal plain’s biodiversity in the southeastern United States would raise awareness of the need to protect the region’s environment.

“When you start talking about something in a way that people understand that it’s different, that it’s special,” Beamer said. “That’s what makes people say, ‘Oh, well, maybe I should take care of that.'”

Jessica Lamb, an assistant professor of biology at St. Cloud State University and a co-author of the study, discovered a Desmognathus pascagoula salamander before she worked on the study as a graduate student and found that its DNA was different from that of other dusky salamanders. She said Pyron and Beamer sought to collaborate on the study because of this documentation of genetic data that matched the Desmognathus pascagoula specimens they studied in previous years.

She said the Pascagoula River in Mississippi, where Desmognathus pascagoula is found, has high biodiversity as one of the largest undembedded rivers in the United States. Lamb said conservationists should focus on habitat conservation because of this connection.

According to Lamb, biologists could study the natural history of Desmognathus pascagoula, such as oviposition behavior, larval periods, and courtship rituals after discovering the species

“What interests me more is figuring out those other pieces of the grim Pascagoula puzzle,” she said.


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