Scientists Discover Mysterious New Flatworm in the United States

Amaga pseudobama
Scientists have discovered a new species of predatory flatworm in North Carolina. Once identified, the researchers found that the species has also been detected in Florida – but have no idea where the species originated. The species, named Amaga pseudobama, is still little studied but is thought to be a terrestrial predator that feeds on soft-bodied organisms. Credit: Matt Bertone

A new species of flatworm, Amaga pseudobama, has been discovered in the southern United States.

A newly discovered species of flatworm has already spread across several southern U.S. states. Notably, this species bears a strong resemblance to Obama nungara, a flatworm that has invaded much of Europe. Due to this similarity, the new species has been named Amaga pseudobama.

An international team reports the discovery of a new species of flatworm. The team includes researchers from National Museum of Natural History in Paris, France, Drexel University and North Carolina State University in the United States, James Cook University in Australia and University of Szczecin in Poland. The new species, first spotted in North Carolina in 2020, is a flatworm, brown in color, a few centimeters in length.

Initial Misidentification and Further Study

The first information received about this species was photos, and the researchers then believed that the specimens belonged to the species Obama nungara, an invasive species native to Brazil and Argentina that has invaded much of Europe. After a molecular study, delayed by the lockdowns of 2020, it became clear that the species was very different from Obama nungara.

Amaga pseudobama Specimens
Amaga pseudobama n. sp. living specimen collected in Kingston, North Carolina in July 2020. Credit: https://doi.org/10.7717/peerj.17904

The researchers then carried out a detailed morphological analysis and a molecular study, including the description of the complete mitogenome, and have now described the species found in the United States under the name Amaga pseudobama, to mark its resemblance to Obama nungara. Like Obama nungara, the new species Amaga pseudobama comes from South America; however, it has never been seen or analyzed in South America.

Apart from North Carolina, the species is also present in Florida, Georgia, and may have already invaded other states. This new species joins other invasive flatworm species discovered in the Southern United States, including Platydemus manokwari.

The resemblance of Amaga pseudobama to Obama nungara will be an obstacle to understanding the distribution of the species from citizen science data, which is usually based on photos taken by members of the public, since it will be impossible to distinguish the two species.

Reference: “A new species of alien land flatworm in the Southern United States” by Jean-Lou Justine​, Romain Gastineau, Delphine Gey, David G. Robinson, Matthew A. Bertone and Leigh Winsor, 24 September 2024, PeerJ.
DOI: 10.7717/peerj.17904