The mysterious broadtail madtom
by Amanda Rossillo | The News Reporter | August 2021
Broadtail madtom (Noturus sp.)
The last installment of Backyard Science highlighted the uniqueness of Lake Waccamaw and the Carolina bays. Lake Waccamaw is such an ecologically important part of Columbus County that we're making it a two-parter, focusing this installment on one particularly mysterious lake resident: the broadtail madtom.
Madtoms are a type of freshwater catfish that are found in warm streams and lakes in eastern North America. There are around 25 species of madtom, but little is known about this group because many of these species are rare or endangered. Madtoms are also generally difficult to find: not only are they very small—usually no more than 4 inches long—but they are also nocturnal and often hide under rocks or debris to avoid predators.
In the 1970s, researchers from UNC Wilmington were surveying the fish species in Lake Waccamaw when they came across a type of madtom they hadn't seen before. Biologist Fritz Rodhe had seen it in the lake too, and another biologist had come across it in some rivers that feed into the Cape Fear River. This madtom was around two and a half inches long, had a unique pigmentation pattern, and an unusually long tail. They recognized that this was a new species and unofficially called it the broadtail madtom. Today, it’s known to be native to the Carolinas, where it has been found in a handful of sites in coastal plain basins. Scientists are currently working to get it formal scientific recognition.
Broadtail madtom distribution map. Courtesy of the Florida Museum.
While broadtail madtoms used to be more common in Lake Waccamaw, they are now extremely rare and are considered a state “species of special concern” that is at high risk of extinction. Not a single broadtail madtom was spotted in the lake between 2002 to 2018, and they were thought to be locally extinct. Finally, in 2019, two were found after an extensive search, renewing efforts to learn more about them. To do this, Fritz Rodhe partnered with the N.C. Wildlife Resources Commission, and they had some unique ideas on how to study this elusive creature.
They developed "madtom motels" that are meant to serve as attractive refuges for the broadtails. These "motels" consist of terra cotta pots with a small opening cut into the rim to serve as an entrance. The pots are weighted down and marked, then placed upside down near the lake's boundaries. They also developed a "madtom hotel," an artificial reef made of concrete blocks with small holes that the madtoms could hide in.
Though broadtail madtoms have not yet been seen in the motels or hotel, biologists with the N.C. Wildlife Resources Commission and Museum are pleased to see other animals using them and plan to place more in the lake. Learning more about the mysterious broadtail madtom will allow scientists to develop management and conservation plans to protect this species. We are looking for volunteers to monitor Madtom Motels at Lake Waccamaw, so if you are interested being part of the madtom hunter team, get in touch with Brian Wuertz, Community Engagement Educator, at brian.wuertz@naturalsciences.org. You can also learn more about ongoing research at the lake by visiting the Museum’s website, where there is a recording of the Lake Waccamaw: A Fishy Field Trip event that we hosted as part of our Darwin Days 2020 programming.