Researchers catch elusive crustacean inside Missouri cave

OZARK, Mo. -- Netted from the chilly stream deep inside Smallin Civil War Cave, bristly cave crayfish No. 11 had no idea she was about to have a tracking device injected into her belly.

The ghostly pale creature waved her sharp claws but was unable to pinch professor David Ashley as he used a syringe to place the transponder device the size of a pencil lead into her body.

"The beauty of a PIT (Passive Integrated Transponder) tag is it provides a permanent record for the life of the animal," said Ashley, moments after the successful insertion. "This one is probably 4 to 5 years old, but we don't really know how long they live. Doing this kind of research is accumulating information that will let you eventually answer that question."

Ashley, a biology professor at Missouri Western State University in St. Joseph, recently took a group of college students into Smallin Cave to track down the elusive bristly crayfish as part of a multiyear project to learn more about the blind crustaceans.

Though not endangered, they are listed as a Species of Conservation Concern, meaning their very limited habitat makes them vulnerable to extinction from chemicals, silt and pollution that can wash into a cave from the surface. Nearly blind, they find their way to food in the dark with their long antennae and sensitive bristles on their legs.

David Ashley, left, a professor at Missouri Western State University, locates a bristly cave crayfish May 18 inside the Smallin Civil War Cave in Ozark, Missouri. Ashley and his students were catching and tagging bristly cave crayfish for study.Andrew Jensen ~ The News-Leader via AP

The Springfield News-Leader reported that, like canaries in a coal mine, the bristlys' presence in a cave -- and whether their numbers are rising or decreasing -- could be a bellwether for the health of the cave environment.

For nearly a decade Ashley has been collecting bristly cave crayfish at Smallin Cave to develop a database on the strange creatures. He has located and tagged more than 100 bristlys, finding them near the mouth of the cave's gigantic opening and as far back as 1,400 feet, where the only light that ever appears is from explorers' headlamps.

Bristly cave crayfish are found in nine southwest Missouri counties and in extreme northeast Oklahoma. At one time some people guessed they lived up to 100 years, but Ashley thinks that's a stretch basic research like his will resolve.

"This one (No. 11) is probably 4 or 5 years old, at least, maybe a little older," Ashley said. "The most recent estimates we have is that they might live up to 25 years."

Wearing boots, waders or mud overalls, his students shone their headlamps into cracks and crevices beneath the clear creek flowing through Smallin Cave. Ashley strung a long tape measure along the way and recorded exactly where each bristly was caught with a small dip net.

David Ashley, a professor at Missouri Western State University, and his students enter the Smallin Civil War Cave on May 18 in Ozark, Missouri. Ashley and his students were catching and tagging bristly cave crayfish for study.Andrew Jensen ~ The News-Leader via AP

The creatures were placed in a small plastic tub filled with stream water, and Ashley and his crew methodically documented each one. Using a Sharpie pen, they wrote an identifying number on each one's back, then weighed and measured each critter.

On larger specimens, Ashley used a special wand that can pick up the identifying data in a PIT tag, if the bristly has one that's previously been inserted.

He keeps a record of each crayfish, building a database that could unlock the secrets of this strange cave animal.

Kevin Bight, who with his wife, Wanetta, owns and operates Smallin Cave as a historical tourism business, has added a lot of knowledge already.

He takes visitors into the cave and knows each nook and cranny, even far beyond the end of the concrete tourist pathway.

In past excursions, Bright photographed bristly crayfish eating a salamander, dining on a dead bat and even devouring a pickerel frog.

"That was really unusual because the frog was still alive and it was clear the bristly had caught it," Bright said.

Ashley isn't the only scientist doing basic research at Smallin Cave.

Shannon Brewer, associate professor of biology at Oklahoma State University, joined Ashley to continue her specialized project that tests water samples for bristly crayfish DNA.

Knowing how many bristlys are in the cave (Ashley's research) helps Brewer fine-tune her DNA testing. Eventually her DNA water sampling might become so accurate that it could be used to estimate how many bristlys are in a cave, without having to physically catch and count them.

"It's a relatively new concept, but it already has been used in the Great Lakes to identify the presence of invasive Asian carp," Brewer said.

Missouri State University graduate student Olivia Graves has been catching and marking salamanders inside Smallin Cave and the adjacent Fielden Cave.

One surprising result that the cave owners suspected but weren't sure of: The two caves are connected.

Wanetta Bright said one of Graves' salamanders that was tagged in Fielden Cave was later discovered more than 600 feet inside Smallin Cave -- evidence of an as-yet undiscovered passageway between the two cavesd