A new species of freshwater stingray, camouflaged for centuries in the muddy rivers of northern South America, has been identified by an international team of scientists. The discovery was made in the Essequibo and Orinoco river basins spanning Guyana and Venezuela.
Researchers from the Smithsonian Institution and local universities first collected specimens in 2024 during a biodiversity survey funded by the National Geographic Society. The new stingray, belonging to the genus *Potamotrygon*, is distinguished by its unique hexagonal denticle pattern and a broader disc width relative to its tail. Genetic analysis revealed a 4.2% divergence in mitochondrial DNA from its closest known relative, *Potamotrygon orbignyi*.
Freshwater stingrays are notoriously difficult to study due to their cryptic behavior and remote habitats. The Guiana Shield region remains one of the least-explored freshwater ecosystems on Earth, with new species of fish and rays described regularly. This new freshwater stingray species brings the total known *Potamotrygon* taxa to 32.
Lead author Dr. Ana Lucia Fernandez of the Universidad Central de Venezuela noted that the species likely went undetected because local fishers often release or discard rays without reporting them. The formal description, published in *Zootaxa* in July 2026, includes detailed morphological measurements and photographs of live specimens.
Conservationists are concerned because illegal gold mining and dam construction threaten the shallow, sediment-rich habitats these rays prefer. The newly discovered new freshwater stingray species may already be at risk, as its entire known range covers less than 10,000 square kilometers.
Experts say this discovery underscores the urgency of cataloging freshwater biodiversity before it disappears. The International Union for Conservation of Nature (IUCN) is expected to assess the species for its Red List within the next two years.
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A New Freshwater Stingray Species Discovered In Guyana And Venezuela Rivers
In the muddy, ever-shifting waters of northern South America, scientists have uncovered a new species of freshwater stingray hiding in plain sight.
Melissa Cristina Márquez, Contributor
Forbes
2 min read
4/10
Guyana and Venezuela rivers
Key Takeaways
- The new freshwater stingray species, from the genus *Potamotrygon*, was identified using genetic divergence of 4.2% in mitochondrial DNA from *Potamotrygon orbignyi*.
- Specimens were collected in 2024 during a National Geographic-funded biodiversity survey in the Essequibo and Orinoco river basins spanning Guyana and Venezuela.
- The ray's distinct hexagonal denticle pattern and broader disc-to-tail ratio differentiate it from other South American freshwater stingrays.
- The total number of described *Potamotrygon* species now stands at 32, with this discovery adding to the known diversity of the Guiana Shield.
- Illegal gold mining and hydroelectric dam construction pose immediate threats to the ray's habitat, which covers less than 10,000 square kilometers.
- The formal species description was published in *Zootaxa* in July 2026, co-authored by scientists from the Smithsonian Institution and Universidad Central de Venezuela.
- Local fishers had long observed these rays but routinely released them, contributing to the species' cryptic status until genetic analysis revealed its uniqueness.
Frequently Asked Questions
The new freshwater stingray species is a member of the genus Potamotrygon, discovered in the Essequibo and Orinoco river basins of Guyana and Venezuela. It was identified through genetic analysis and distinct morphological features such as hexagonal denticle patterns.
The stingray was discovered in the Essequibo and Orinoco river basins spanning Guyana and Venezuela in northern South America. These rivers are part of the Guiana Shield, a region known for high freshwater biodiversity.
Scientists used mitochondrial DNA sequencing, which showed a 4.2% divergence from the closest known species Potamotrygon orbignyi. They also examined physical traits like disc width and denticle arrangement to confirm it as a new species.
This discovery highlights the hidden diversity of freshwater rays in South America and underscores the need to protect fragile river ecosystems from threats like mining and dams. It also adds to the scientific knowledge of Potamotrygon taxonomy.
Illegal gold mining and hydroelectric dam construction are destroying the shallow, sediment-rich habitats the stingray prefers. Its entire known range is less than 10,000 square kilometers, making it potentially vulnerable to extinction.
The formal description of the new freshwater stingray species was published in the journal Zootaxa in July 2026.
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