Like many stingray species, motoro rays lie on the bottom of rivers, almost completely covered in sand, and wait for prey.
  • Size

    3.3 feet (1 m)
  • Diet

    Small fishes and invertebrates
  • Range

    River basins in Northern South America
  • Habitat

    Shallow, murky waters

Physical Characteristics

  • Coloration is brownish with circular spots on the back and tail.
  • Flattened, disc-shaped body. Short tail has no dorsal fin, while its small pelvic fins are tucked under its pectoral fins. Venomous spine on the tail.
  • Can grow to about 3.3 feet (1 m) in diameter and weigh 33 lbs. (15 kg).

Animal Fact

Female motoro rays can give birth to up to 16 pups at a time.

Diet / Feeding

  • Diet consists of small fishes and invertebrates.
  • Commonly lies on the bottom, almost completely covered with sand, waiting for prey.

Range / Habitat

  • Occurs in many of the river basins in Northern South America including the Amazon, Orinoco, Parana-Paraguay and Uruguay.
  • Found in shallow, murky waters.

Reproduction & Growth

  • Ovoviviparous: gives live birth to up to 16 pups at a time.

Conservation Status

  • “Data Deficient” on the IUCN Red List.

Additional Information

  • Also known as the “ocellate river stingray.”
  • Powerful venom in its barb can cause severe pain – this animal is feared more than the piranha throughout its range.
  • Barbs are replaced up to three times a year. Stingray barbs are a modified scale made of dentine, an enamel-based material much like dermal denticles on sharks and rays.
  • Ancestors are from marine waters.
  • Few predators except for some larger fish and the caiman.


  • Sharks and Rays Guide to the World. Hennemann, R., pg. 221
  • Smithsonian Institution Animal.  Burnie, D. and Wilson, D., pg. 477
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