Motoro Stingray Care Guide - Aquarium Setup, Diet & Breeding

The Motoro Stingray is a large freshwater ray with a rounded, disc-shaped body, a long whip-like tail and a striking pattern of rings, rosettes and spots. Its colouration ranges from tan and brown to greyish olive, usually with contrasting markings that help it blend into a sandy or muddy riverbed. The pattern is highly variable, and individual rays can look noticeably different from one another.

This species spends much of its time resting on or moving across the bottom, using its broad pectoral fins to glide through the water. Its eyes sit on the upper surface of the disc, while the mouth and sensory structures are positioned underneath, allowing the ray to search the substrate for hidden prey.

Motoro Stingrays are ambush predators that detect movement and electrical signals from animals concealed beneath the substrate. They use their powerful jaws to crush and consume a variety of bottom-dwelling prey, and their rear tail spine is a defensive weapon rather than a hunting tool.

In the wild, they inhabit slow-moving channels, flooded forests, lagoons and sandy or muddy shallows that may change considerably with seasonal flooding. Their popularity comes from their unusual shape, intelligent behaviour and individual personalities, but their adult size and venomous spine make them a specialist species for experienced aquarists.

The Motoro Stingray is native to freshwater rivers, tributaries and floodplain habitats across tropical and subtropical South America, including parts of the Amazon, Orinoco, Paraná and related river systems. Its exact appearance and pattern can vary between different geographic populations.

An adult Motoro Stingray requires a very large aquarium of at least about 680 litres, with a substantially larger system preferred for long-term care or multiple rays. A footprint of approximately 180 by 75 cm is a bare minimum for one adult, while greater length and width are more important than excessive height. Use a deep layer of soft, fine sand that will not abrade the ray’s underside, leave generous open floor space for movement, and avoid sharp rocks, rough ornaments and exposed equipment. Provide powerful, reliable filtration, strong oxygenation and secure covers, while keeping cables and heaters protected from the ray’s body and tail.

Males commonly reach around 40 cm in disc width and approximately 60 cm in total length, including the tail. Females are usually larger and can reach about 50 cm in disc width and roughly 75 cm in total length, equivalent to around 20 inches in disc width and 30 inches overall; males are approximately 16 inches in disc width and 24 inches in total length.

Motoro Stingrays are carnivores that should receive a varied diet of earthworms, prawns, mussels, suitably sized fish, insect larvae and high-quality sinking carnivore foods. Juveniles generally need frequent meals, while adults can be fed less often according to body condition. Food should be placed on the substrate where the ray can locate it, and uneaten portions should be removed promptly to protect water quality. Avoid relying on feeder fish, particularly unquarantined or nutritionally poor species.

Suitable companions are robust, peaceful fish that occupy the middle or upper levels of the aquarium, such as large peaceful characins, silver dollars, severums and other appropriately sized South American community fish. Avoid small fish that may be swallowed, fin-nipping species, aggressive cichlids, territorial bottom dwellers and other animals that may harass the ray. Tankmates must also tolerate the ray’s warm, soft-to-moderately hard freshwater conditions, and care is essential because any handling or maintenance around the aquarium carries a risk from the tail spine.

Motoro Stingrays are livebearers and can breed in a spacious, mature aquarium when provided with excellent water quality, suitable temperatures and compatible adults. The male grips the female with his claspers during mating, and the female later gives birth to fully formed pups rather than laying eggs. Gestation commonly lasts several months, after which the pups should be monitored carefully because adults may injure or consume them. Breeding should only be attempted by experienced keepers with facilities large enough for adult rays and their offspring.

Females grow larger and heavier than males. Mature males have a pair of prominent claspers at the base of the tail, which are absent in females; these reproductive organs are the clearest visible difference between the sexes.