Species Fact Profile: Ocellated Stingray (Potamotrygon motoro)

                                                                  Ocellated Stingray

                                            Potamotrygon motoro (JP Muller & Henle, 1841)

Range: Northern and Central South America, including the Amazon, Uruguay, Parana-Paraguay, and Orinoco River systems

Habitat:  Calm Freshwater Habitats – slow moving rivers, lagoons, streams, with a preference for sandy-bottoms to facilitate burrowing.  Found for 0.5-10 meters depth

Diet:  Neonates feed on plankton.  Juveniles feed on small mollusks, crustaceans, and aquatic insect larvae.  Adults primarily consume fish

Social Grouping: Primarily solitary outside of breeding season.  Not territorial, do not maintain home range

Reproduction: Ovoviviparous.  Breeding takes place at night, male clamping onto the female with his jaws.  Mate during the dry season (June through November) with births taking place during the rainy season.  Eggs about 3 centimeters in diameter.  Young nurtures of fatty secretions inside the mother’s uterus.  Gestation usually 6 months, but has been as short as 3 months in aquariums.  3-21 pups (average is 7, but always an odd number) born per litter.  Larger females tend to give birth to larger litters.  May abort young under stress. Females usually give birth to one litter a year for three years, then take a few years off

Lifespan: 15 Years

      Conservation Status:  IUCN Data Deficient

• Roughly oval-shaped.  Robust tail ends with a venomous spine.  Maximum length of 100 centimeters (more commonly 50 centimeters), weigh up to 35 kilograms (more commonly 15 kilograms).  Tail of equal length to disc. Females usually slightly larger than males.
• Eyes positioned on dorsal surface of the head, providing 360 degree visibility. Possess electroreceptors, highly sensitive, that allow for detection of prey and predators.  Also have well-developed sense of smell
• Background color is greyish-brown (very light, almost tan in some individuals, very dark in others), with orange-yellow dorsal eyespots, each surrounded with a black ring larger than the eyes.  Coloration extends onto the tail\
•     Pups are sexually mature at 20-44 centimeters in disc length, with females requiring a larger size than males to be deemed mature and captive specimens reaching sexual maturity at a smaller size than wild individuals (in males, sexually maturity can also be ascertained by the relative size of the pelvic claspers)       
• Undergo cyclical migration patterns within freshwater systems, traveling up to 100 kilometers, cause unknown      
• Major defensive mechanisms are camouflage, burrowing down into the river substrate, and the tail, which has a venomous spine at the tip.  Primary predators are caimans, though may be consumed by larger fish species as well
• Also known as the peacock-eye stingray, orange-spot stingray, or the black river stingray.  Some consideration that it may represent a species complex of closely-related freshwater stingrays
• Status is unknown throughout range, but not believed to be in danger due to widespread range, generalist dietary and habitat requirements, and little commercial demand
• One of the most popular freshwater stingray species seen in the pet trade.  Husbandry considered fairly easy, but requires a large tank.