Air Date: Week of September 12, 2025

Pictured above is a painted turtle. Don Lyman initially mistook this painted turtle with a bumpy carapace for a red-eared slider. (Photo: Don Lyman)

Living on Earth’s Don Lyman is back in classrooms teaching biology as a substitute and incorporating his passion for herpetology wherever he can. But one unusual classroom turtle presented an identification puzzle, and a teaching moment that he recounts in his essay “A Tale of Two Turtles.”

Transcript

DOERING: It’s Living on Earth, I’m Jenni Doering.

CURWOOD: And I’m Steve Curwood.

We are back to school and that means Living on Earth’s Don Lyman is back in classrooms teaching biology as a substitute. And before school let out for the summer Don had a teaching moment he calls “A Tale of Two Turtles.”

LYMAN: One morning last year, I walked into a 9th grade biology class for my first substitute teaching assignment of the day and was delighted to see a large, cube-shaped aquarium in the back of the room with a six-inch turtle basking on a platform under a heat lamp. As a biologist and hospital pharmacist who teaches college part-time, I’m always looking for ways to engage my young high school boys in conversation about science. And with herpetology — the study of reptiles and amphibians — being my primary area of interest in biology, turtles work just fine for this purpose.

From the teacher’s desk, the turtle looked like a red-eared slider. Great, I thought, a two-fer – I can talk to the boys about turtles and exotic invasive species. Red-eared sliders are native to parts of the Midwest and South, but not to Massachusetts, where the boys’ prep school I teach at is located. They have been introduced into Massachusetts and other parts of the Northeast, however, most likely having been released by their owners when the cute baby turtles they bought in pet shops grew bigger than expected. Like most exotic invasive species, the concern is that they may outcompete native species or introduce diseases, which could disrupt the ecological balance of their new home.

When I walked to the back of the classroom for a closer look, my initial identification didn’t hold up. The namesake red markings on the side of the head that are characteristic of red-eared sliders were absent. And the carapace — the top part of the turtle’s shell — wasn’t the standard dark green slider color. It was black, with red markings along the lower edges. The color pattern looked more like a painted turtle, but painted turtles have smooth carapaces, and this turtle had a decidedly bumpy slider-like carapace. Could this be a painted turtle with a deformed carapace?

Unsure of the species, I gave a brief, tepid turtle talk, and told the class that I had initially thought the turtle was a red-eared slider, but it looked a little like a painted turtle, and now I wasn’t sure what kind of turtle it was. The unidentified turtle stared at me nonchalantly while my reputation as a biologist teetered on the brink of oblivion.

Later in the day, I subbed in another classroom, which also had a large aquarium, but with a 10-inch turtle that was most definitely a red-eared slider. Confident of my species identification, I proceeded to give the mini-lecture I had wanted to give earlier in the day, telling the class a little about red-eared sliders and exotic invasive species.

The next day, I wound up subbing in a freshmen biology class with the mystery turtle once again. I tried to ignore the turtle until one of my students blurted out, “Mr. Lyman, I know you like reptiles. Do you know what kind of turtle that is?” Et tu, Eli? I froze for a second, then told the class about my red-eared slider/painted turtle with a deformed carapace theory. “I’m going to take a picture and send it to some of my turtle friends,” I informed them.

I snapped a photo on my cellphone and texted it to a few of my herpetologist colleagues with my mystery turtle hypothesis. I nervously waited for a reply.

A few minutes later, my cell phone buzzed with a message from Bryan Windmiller, a herpetologist and conservation biologist at Zoo New England in Boston. “Agreed,” he texted. “Looks like a painted, maybe with growth anomalies from being raised in captivity.”

I regained my composure, cleared my throat, ahem, and announced to the class my hypothesis had been validated.

“So, you were right, Mr. Lyman,” one of my young inquisitors said, in a kind of “you lucked out this time” tone.

My herpetological reputation was restored.

The turtle, however, looked unimpressed.

CURWOOD: [LAUGHS] Living on Earth’s Don Lyman.

 

Links

Learn more about Don Lyman

Learn more about the painted turtle from iNaturalist