A team of researchers from Free State High School may have discovered a new species of microscopic invertebrate in Costa Rica.

Kenneth Nickell, a Free State science teacher who led sample-collection expeditions in June and November, said his student assistants were now in the lab trying to prove they found evidence of a previously unknown critter.

“It’s exciting,” said Ilya Faibushevich, a senior who went on the trek with Nickell. “This could wind up in biology books.”

Nickell said the group was focused on the study of creatures known as tardigrades. They’re invisible to the naked eye, but under a microscope, a head, legs and other features can be seen. Tardigrades often are called “water bears” because of their stumpy legs and lumbering gait.

Hundreds of varieties live in the water films around lichens and mosses, but they can be found in marine and fresh-water environments. Tardigrades feed on fluids in plant and animal cells.

They can withstand extreme environmental conditions, Nickell said. Temperatures near absolute zero, X-ray radiation 1,000 times the human lethal dose and pressure six times what is found in the deepest ocean trench don’t phase them.

Samples in labs have been known to contract, expel water and shrivel up, only to survive in this state for years before being revived after immersion in a liquid.

While in Costa Rica, Nickell’s team collected tardigrades from trees in the city of San Jose, along a beach, in lowlands and from forested areas accessible by donkey.

“They grow on trees,” said Ginger Ellenbecker, a Free State senior on the trip during Thanksgiving break.

The field research wasn’t complicated, Ellenbecker said. Students snapped off pieces of lichen-covered bark and placed the chunks in plastic bags.

Ellenbecker, who is interested in studying biology in college, said the research could be significant because tardigrades offered clues as to how living tissue might be stored in ways that improve transplantation of human organs.

Free State senior Jameelah Lang is taking an independent study course with Nickell to do much of the laboratory analysis of samples.

Her role has been to locate, preserve and mount the creatures on microscope slides.

“It’s tedious, especially when you don’t find anything for a long time,” Lang said. “You have to be patient.”

Nickell said careful preservation of samples was essential to verifying a new species. Samples must be sent to scientists in other parts of the world for examination to substantiate a claim.

“We’re adding to the body of science,” Nickell said.