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Last year, Illinois Natural History Survey scientist Chris Taylor and his colleague Guenter Schuster of Eastern Kentucky University did something no one else had done since 1884. They described a new species of crayfish in the genus Barbicambarus, which, up until that point, had included only the single species described 126 years before.
Now, you may be thinking, a new species of crayfish, what’s the big deal? Let me tell you. The crayfish Taylor and Schuster described, Barbicambarus simmonsi, is a whopper—at least for a crayfish. In contrast to most of its relatives, which are only a few inches long, this one can stretch eight inches from the tip of its claws to the tip of its tail. Rest one on a dollar bill and it will hang off in every direction. [The new species, Barbicambarus simmonsi (left) is more than twice the size of a typical crayfish found in the same creek. Photo and caption by L. Brian Stauffer.]Aside from being big, the new species is distinguished by the fact that its antennae are covered with hair-like bristles, or “setae.” Of the more than 600 species of crayfish known from around the world, only the two members of Babicambarus possess bristly antennae, and nrobody knows yet what function the setae serve. The appearance of its antennae accounts, in part, for the common name Taylor and Schuster have proposed for the new species, “Tennessee bottlebrush crayfish.” The “Tennessee” in that name refers to the river drainage in which it occurs, and that’s another fascinating aspect of the story.
The Tennessee bottlebrush was discovered in Shoal Creek, which originates in south central Tennessee and flows into northern Alabama, where it empties into the Tennessee River. In a funny kind of twist, that drainage is one of the last places in the U. S. where biologists would expect to find a large new species of stream creature. That’s because it contains such a rich assemblage of aquatic organisms—especially fish, mussels and crayfish—and it is so accessible that it has been surveyed extensively over the past century and a half.
Taylor and Shuster were motivated to go to Shoal Creek looking for a large crayfish with hairy antennae by photographs of one a colleague forwarded them in summer 2009. At about the same time, they also learned such a creature had been collected by Jeffrey W. Simmons, an aquatic biologist with the Tennessee Valley Authority (which is why the scientific name, “simmonsi,” honors him.)
They arrived at Shoal Creek on October 12, 2009, accompanied by two other biologists. They searched hard for two hours at their first survey site but found nothing unusual, and were ready to move on when they decided to flip one last, large, flat boulder. Beneath it they found a crayfish twice the size of any others they had found that day, with hairy antennae—exactly what they were looking for.
Until they had specimens in hand, Taylor and Schuster had worked on the assumption that the big crayfish in Shoal Creek were the same species described back in 1884, Barbicambarus cornutus. Cornutus had been found only in the drainage of Kentucky’s Green River, 130 miles away, but might easily have been transported to Shoal Creek, perhaps by an angler.
In the lab, though, Schuster found that the creature they collected differed significantly in certain important physical characteristics, and Taylor’s analysis of the DNA of the new crayfish provided further confirmation they were the first scientists to describe it.
An extensive search of crayfish collections turned up no previous specimens of Tennessee bottlebrush crayfish that had been overlooked or mislabeled, and further collecting expeditions in the area where it was first found have yielded only a handful of more specimens, so it is presumed to be rare.
But still, it was right there, waiting to be discovered.
Chris Taylor hopes the discovery of the Tennessee bottlebrush crayfish will help awaken people to the need for continuing biological investigation within the United States, and inspire them to support it. Beyond that, he hopes it will encourage people to spend time exploring streams themselves. In his words, “You never know what you might find.”
