Large-spot river stingray

7/1/2019

Heck yes, we are diving into another freshwater stingray my friends. Known as the “large-spot river stingray” or the “reticulated freshwater stingray,” scientifically they only go by one name: Potamotrygon falkneri. You guessed it, they belong to the family Potamotrygonidae and are also from tropical and subtropical South America like their relatives! Specifically, the best-known population for this ray is found in Paraguay, Brazil, Uruguay, and northeastern Argentina.

And yes, you can also see these rays in aquariums—but they can grow up to 89 cm (35 in) in total length and up to 52 cm (20 in) wide… so they need quite a big tank. Originally described in 1963, their dorsal (top) side is covered in spots. But, like many others in this family, their pattern varies and no two look exactly alike. There are intermediates between the various patterns they have, and all are a variant of this species!

We don’t know much else about their biology or their reproductive system—however, a momma ray in an aquarium had a gestation period of about 20 weeks and produced two pups. So this may give us a glimpse of what reproduction is like in the wild!

Also known as the “tiger stingray,” they can be seen with a yellow-orange hue on top. But again, their exact color is variable. Makes it hard for people describe, that’s for sure! This is why they are assessed by the IUCN as Data Deficient (DD).