Ocellated River Stingray
Just one of a few ray species that evolved in freshwater, the ocellate river stingray has an ovular shape with a grey and brown upper surface area covered in yellow-orange spots. It may be beautiful, but watch out for that big spine at the end of its strong tail as it can deliver a painful sting!
Habitat: Found in South American river systems, this species of stingray is heavily populated in the Brazilian Amazon region. They prefer tropical freshwater rivers at varying depths from half a meter deep to ten meters deep. Calm waters are their favorite and they can be found partially buried under sand at the edges of brooks, streams, and lagoons.
Diet: They are primarily carnivores, eating fish, insects, mollusks, and crustaceans. As pups, they will eat plankton, introducing a carnivorous diet as they grow.
Family Life: The ocellate river stingray is polygynous, however, the males only appear to mate every few weeks. Rather than using cues from the seasons, this species uses the river’s hydraulic cycles to inform their reproduction. Although the average number of offspring is seven, they can have 3 to 21 pups at a time!
The conservation status of the ocellate river stingray is data deficient.
- In many areas, there are no regulations about the traffic or exportation of freshwater stingrays. They are caught by fisherman for food and fish trade due to their attractive patterns.
- Habitat degradation is also a major threat caused by damming and the construction of ports along the river where the stingrays live.
- They have eyes positioned on the top of their heads, oriented in opposition to one another, giving them a nearly 360-degree field of vision!
- Because of their electroreceptor system, they can perceive low-frequency electrical signals that allow them to detect prey that cannot be seen by the naked eye.
CLASS: Chondrichthyes (cartilaginous fishes)
ORDER: Rajiformes (Batoidea, flattened cartilaginous)
FAMILY: Potamotrygonidae (river stingrays)
GENUS: Potamotygon (freshwater stingrays)
SPECIES: Potamotrygon motoro (ocellated river stingray)
LIFE SPAN: ~ 12 – 15 years
SIZE: 39.37 inches (100 cm)
WEIGHT: Up to 33.03 pounds (15 kg)