Two New Species of Crayfish Discovered in Alabama and Mississippi
In 2011, a group of researchers traveled to southern Alabama and Mississippi in search of the Rusty Gravedigger crayfish (Lacunicambarus miltus). They wanted to refine the species’ range and hoped to find a new population west of Mobile Bay. Instead, they found a potentially undescribed species of crayfish.
Years later, a team led by Mael Glon, a Ph.D. candidate at Ohio State University, and USDA Forest Service scientist Susie Adams returned to Mobile Bay in January 2020.
They discovered two new species of burrowing crayfishes: the Lonesome Gravedigger (L. mobilensis) and the Banded Mudbug (L. freudensteini). Their results were published in the journal Zootaxa. Both species are small, beautiful, and ecologically important.
The Southeast is home to more freshwater crayfish species than anywhere else in the world. Alabama alone has almost 100 species, while Mississippi claims nearly 65. Discovering two new southeastern crayfish species — especially while searching for one — is remarkable. For Glon, the species are a “reminder of how much we don’t know about the natural world.”
They also help us understand a fundamental part of conservation work: the size of a species’ range. Bound by Mobile Bay to the east and Lucedale, Mississippi to the north, the Lonesome Gravedigger has a 400 square mile range. The Banded Mudbug is limited to an area about half that size between Mobile Bay and the Pascagoula River.
Because of their small ranges and scarcity even in suitable habitats, the authors considered both crayfishes Vulnerable (to extinction) by the criteria of the American Fisheries Society.
These findings are concerning, as a restricted range increases a species’ sensitivity to environmental change. The Banded Mudbug is also limited by its burrowing behavior. Many Mudbug burrows are located at low elevations, with some are only a few kilometers away from the Gulf of Mexico. Rising sea levels and saltwater intrusion could threaten the species’ long-term survival.
Beyond helping us understand threats to southern crayfishes, the Lonesome Gravedigger and the Banded Mudbug are beautiful. Both have vibrant combinations of olive green, blue, or brown, with orange and red highlights. The vivid blue claws of the blue-morph Banded Mudbug are particularly striking. For Adams, coloration is one of the great mysteries of the crayfish world. “Why does an animal that lives underground and that comes out primarily at night have these great colors?”
This is only one of many questions that have yet to be explored. Further research is necessary to understand the life history of these crayfishes, refine their conservation status, and define threats to their persistence.
Though there is a lot to learn, one thing remains clear: “there is still lots of diversity to discover where we live as long as we’re willing to look closely,” says Adams.
Glon agrees. While people often associate undiscovered species with the deep ocean or tropical rainforest, “you can literally find a new species in your backyard in rural Mississippi or Alabama.”
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For more information, email Susie Adams at susan.adams@usda.gov.