A new research paper published in Zootaxa describes five new species of freshwater mussels in the southern U.S., providing the scientific foundation for protecting the most imperiled group of animals in North America.
Researchers from Shedd Aquarium, Arkansas State University and the U.S. Geological Survey discovered the new species after testing the DNA of mussels found in rivers in Missouri, Arkansas, Mississippi, Alabama, Louisiana and Texas. These newly identified mussels, in the genus Obovaria , are rare and only live in specific geographic areas, underscoring the need for region-specific conservation strategies.
Surveying and monitoring freshwater mussel populations is challenging due to similarities in shell appearance, historical misidentifications and incomplete sampling across the southern U.S. region. Over the last 20 years, researchers, including the study’s authors, waded through rivers wearing masks and snorkels while searching muddy stream bottoms for mussels. Researchers took samples of genetic material from the mollusks to bring back to labs for later analysis and species identification.
The findings of this study fill in critical knowledge gaps about what freshwater mussel species exist and where they are found. Recognizing distinct species enables scientists and resource managers to better assess extinction risk, prioritize conservation actions and habitats, and guide recovery efforts for imperiled species.
"Identifying new species is the foundation of biodiversity conservation," said Dr. Kentaro Inoue, research biologist at Shedd Aquarium and lead author of the paper. "Conservation efforts can only protect what we recognize, and without this work, we risk certain species going extinct before they’re even known to science.”
Mussels are the hidden champions of our freshwater ecosystems, quietly filtering water and maintaining healthy ecosystems. Freshwater mussels filter and remove algae and bacteria from waterways, many of which are sources of drinking water for communities. The mollusks spend most of their lives half-buried in the muddy bottoms of lakes and streams, yet they are vital to healthy waters and benefit the people, animals and plants that call these areas home.
"Our discovery and descriptions of these new freshwater mussel species demonstrate how much we still have to learn about the biodiversity in our rivers," said Nathan Johnson, coauthor on the study and a research biologist at the U.S. Geological Survey Wetland and Aquatic Research Center. "It also underscores the value of collaborations among federal and state agencies, non-government organizations, and natural history institutions. Together, our efforts are helping inform management decisions that protect waterways and support the health of fish, wildlife, and human communities."
The new mussel species are named the Mobile Hickorynut ( Obovaria sipseyensis ) , White River Hickorynut ( Obovaria neeskaensis ) , Big Thicket Hickorynut ( Obovaria pinetorum ) , Tallahatta Hickorynut ( Obovaria tallahattae ) and Acolapissa Hickorynut ( Obovaria lumbo ) . The full findings of this research have been published in Zootaxa under the title, " Description of multiple cryptic species of Obovaria Rafinesque, 1819 (Bivalvia: Unionida) from the Mississippi Embayment and Gulf coastal rivers of North America ."
Zootaxa
Animals
Description of multiple cryptic species of Obovaria Rafinesque, 1819 (Bivalvia: Unionida) from the Mississippi Embayment and Gulf coastal rivers of North America
23-Sep-2026