That cute pet turtle in the home or pet-store terrarium — the one with the distinctive red stripe darting back behind its eyes — has crawled into the ranks of creatures that aren’t welcome in state waters.

Like the Asian carp and zebra mussels, the red-eared slider is not native to Minnesota and has come to pose a threat to species that are, the Minnesota Department of Natural Resources said Tuesday.

“They may compete with our native turtles, including the state-listed [threatened] Blanding’s turtle, for resources such as food, nesting sites and optimal basking areas,” said DNR nongame wildlife biologist Christopher Smith.

The red-eared slider is probably the most common turtle sold in pet shops nationwide, sometimes as a walnut-sized hatchling. The “slider” in the name refers to the turtle’s ability to slide easily and quickly off rocks or logs when threatened by predators.

In captivity, the young turtles quickly grow to between 6 inches and a foot long, and eventually require a larger space to roam, Smith said. The result, he said, is that well-meaning pet owners decide to set them free.

That can cause a host of problems. The pet turtles, or even native turtles taken in temporarily as pets, can harbor diseases like salmonella or parasites that can spread to wild turtle populations, jeopardizing entire populations in an area, Smith said.

The sliders may also interbreed with native turtles, producing offspring with mixed genes that may not be hardy enough to survive winters.

John Moriarty, senior manager for wildlife at Three Rivers Park District, said that as the climate changes with warmer winters, red-eared sliders will stand a better chance of surviving in Minnesota. Already there are three known populations living year-round in southeastern Minnesota, said Moriarty, co-author of “Amphibians and Reptiles Native to Minnesota.”

“Right now they can persist in Minnesota, but we’ve never seen any breeding here,” he said.

If that begins and red-eared slider populations increase as average temperatures warm, Moriarty said, “that would be a big issue, because wherever they’re found, they become an invasive species.”

The manager of a PetSmart store in the Twin Cities said he sells red-eared sliders when they’re available, usually as hand-sized adult males, but they’re not a high-traffic item. The manager declined to give his name, citing company policies against interviews, but said that red-eared sliders are sometimes mistakenly marketed as painted turtles, and sell for $20 to $30 each.

Adoption options

DNR public information officer Lori Naumann said that pet owners with unwanted turtles should look for local humane or nonprofit societies such as the Minnesota Herpetological Society that might put the animals up for adoption.

The Herpetological Society finds homes for more than 2,000 unwanted snakes, lizards, turtles and other amphibians and reptiles each year, Smith said. Before calling that group, he advises people to ask around to see if a neighbor, teacher or local nature center might take an unwanted turtle or other pet for personal or educational purposes.

Moriarty said pet owners should be aware that turtles can live for 40 years or more, so purchasers should have a plan for taking care of them.

“It’s a long-term commitment,” he said. “Otherwise people would be better off getting a hamster or a gerbil that only lives for four or five years.”