Freshwater Stingray (Motoro)

The Freshwater Stingray, specifically Potamotrygon motoro, is the most widely kept and arguably the most beautiful of all freshwater ray species — a living disc of tan, brown, and gold adorned with a mesmerizing pattern of orange-rimmed ocelli (eye-spots) that varies uniquely from individual to individual, making each specimen a one-of-a-kind living artwork. Native to the Amazon and Orinoco river basins, this species has adapted entirely to freshwater over millions of years, losing the salt-regulating physiology of its marine ancestors and developing a flattened body plan perfectly suited to the sandy river bottoms it inhabits.

At The Fish Collection, we source our Motoro Stingrays from reputable breeders and licensed collectors who handle these animals with the specialized care they demand. Every specimen we offer has been quarantined, dewormed, and confirmed feeding on a varied diet before listing. Potamotrygon motoro reaches a disc width of approximately 18 inches in captivity, with exceptional specimens exceeding this in large systems. The total body length including the tail can reach 30 inches or more.

Housing requirements are substantial. A minimum 300-gallon aquarium with a large footprint — wide and shallow rather than tall — is essential. The substrate must be fine, smooth sand that the ray can bury in, and the tank should be free of sharp decorations or rough surfaces that could damage the ray's delicate ventral skin. Powerful filtration rated for at least twice the tank volume is necessary, as stingrays are messy eaters that produce significant waste. Water temperature should be maintained between 75 and 82 degrees Fahrenheit, with a pH of 6.0 to 7.0 and very soft water.

The venomous caudal spine is a serious consideration. Potamotrygon motoro possesses a serrated, venom-coated barb on the tail that can inflict excruciating wounds requiring medical attention. Tank maintenance must always be performed with awareness of the ray's position, and keepers should never reach blindly into the aquarium. Long tools, careful observation, and deliberate movements are mandatory safety protocols.

Diet consists of meaty foods: earthworms, shrimp, mussels, fish fillets, and high-quality sinking pellets. Feed daily for juveniles, every other day for adults. A well-fed Motoro is an active, personable animal that quickly learns to associate its keeper with food and will rise to the surface at feeding time.