Former APSU Graduate Student Discovers New Turtle Species

Clarksville, TN – There was something strange about the turtle, aside from its enormous head. Normally, the other species in the broad-headed group of map turtles confined themselves to a single major river system, but Austin Peay State University alum Josh Ennen (’05) knew this particular turtle was listed as living in two separate rivers.

“That was interesting, so I started looking at the genetics of the species,” he said. He compared populations of Graptemys gibbonsi (Pascagoula map turtle) from the Pascagoula and Pearl rivers.

“They were genetically different from each other,” he said. “Next, we went back and did morphological analyses to see if they were physically different. And we concluded that they were different morphologically.”

It was a pivotal moment for the study of field biology. Ennen had just discovered a new species of turtle – Graptemys pearlensis. It was the first turtle species described in this country since 1992.

“What’s rare about the discovery is that it was in a developed country, the United States, and it’s a larger vertebrate,” he said. “The discovery of most new species or large vertebrate are usually restricted to isolated and/or remote portions of the globe, such as the rain forests.”

As for G. pearlensis, Ennen said, “It’s a conspicuous animal that people knew where it was, they just didn’t identify it correctly.”

Ennen, a Ph.D. student at the time of the discovery with the University of Southern Mississippi (USM), recently had a paper he co-authored on his findings published as the cover article for “Chelonian Conservation and Biology: The International Journal of Turtle and Tortoise Research.”

“It made the front cover,” he said. “All this hard work of collecting data and analyzing data, but I look at it as just another manuscript.”

Ennen’s interest in field biology began almost a decade ago when, as an undergraduate student at Maryville College, he conducted research on frogs for his thesis. In 2003, he enrolled at APSU as a graduate student, eager to work with the school’s Center of Excellence for Field Biology.

It was while studying under APSU biology professor Dr. A. Floyd Scott that Ennen found his new interest – turtles.

“It was pretty much that turtles were where the opportunity was to do research,” he said. “I worked under Dr. Scott. I did two studies on a turtle species in Tennessee, the striped neck musk turtle. I published one paper for tracking turtles for 24 hours, to determine their daily movement patterns.”

Ennen graduated from APSU in 2005, and he recently earned his Ph.D. at USM. Now, he’s in Flagstaff, AR, doing postdoctorate work as a wildlife biologist for the U.S. Geological Survey.

But his doctoral work in the southeastern United States, identifying the 57th species of turtle living in this country, will have a significant impact on that area of field biology for years to come. Ennen, however, is simply happy to contribute to the field’s scholarly conversation.

“I get excited when I do good work and I publish something,” he said.

For more information on the APSU Center of Excellence for Field Biology, contact that office at 931-221-7019.