PASCAGOULA, Miss. – Scientists say they've found a new species of turtle in the Pearl River, and they've named it, aptly enough, the Pearl map turtle.
For a long time, scientists believed the Pascagoula map turtle was alone in the Pascagoula and Pearl rivers. That changed with the findings by Jeff Lovich and Josh Ennen, both with the U.S. Geological Survey.
The Pearl map turtle is 57th turtle species native to the United States and the 13th map turtle. Twenty-nine species can be found in Mississippi.
Lovich's research in 1992 led to his discovery of the Pascagoula map turtle and the Escambia map turtle, which is found in the Escambia River system. He told The Mississippi Press that he had noticed "very subtle differences between the turtles that lived in the Pearl and Pascagoula" rivers while doing research in the 1990s.
"I thought, 'Well, I'll leave those for somebody else to work out,"' he said.
That somebody was Ennen, who works for Lovich at the USGS Southwest Biological Science Center in Flagstaff, Ariz. Ennen discovered the Pearl map turtle while doing research on map turtle species for his doctorate at the University of Southern Mississippi.
Lovich said Ennen called him and said new genetic data showed differences between the Pascagoula and Pearl map turtles.
"The differences between the turtles in the Pearl and Pascagoula were significant and he wanted to know if I wanted to team up with him and run my analyses based on color pattern, measurements of the shell and those sorts of things and combine the data with his new genetic information based on DNA and we did that," Lovich said.
"The results were clear. They were definitely different species," Lovich said.
The female Pearl map turtle is about dinner-plate-sized and the male is tea-saucer-sized, he said. The larger females can use their jaws to crush open clams while the smaller males eat mostly insects and fish.
Lovich said map turtles get their name from yellow lines on their shells that resemble roads on a map. The Pearl map turtle has an unbroken black stripe on its shell while the Pascagoula map turtle's stripe is broken, he said. The Pearl map turtle has less yellow coloring in its shell than its Pascagoula cousin, he said.
"The neat thing about rivers in the southeast United States, all the ones that drain into the Gulf of Mexico, they have amazing biodiversity," Lovich said. "In fact, Alabama probably has more species of clams, fish, crayfish, turtles than just about any place on earth."
He said rising and falling sea levels led to species being separated and joined over tens of thousands of years.
"It is a kind of a laboratory for evolution, if you will," Lovich said.