Porcupine River Stingray

Potamotrygon hystrix is a robust, wide-bodied freshwater ray native to the Paraná-Paraguay river drainage, reaching disc widths of up to 60cm in mature individuals. It is one of the more cold-tolerant potamotrygonid species, reflecting the cooler sub-tropical conditions of its native habitat in southern South America. In the aquarium it proves hardy once established, though water quality standards remain as demanding as for all stingrays. Its colouration is relatively subdued — ochre to brown with pale mottling — but its sheer size and physical presence more than compensate. Pairs have been bred in captivity in specialist facilities. Substrate must be fine sand to avoid abrasion to the ventral disc surface.

Water: 22–28°C, pH 6.0–7.5, moderate hardness acceptable (2–15 dGH); zero ammonia/nitrite. Tank: Minimum 700L, long footprint, deep fine sand, minimal hard decor, strong external filtration. Feeding: Carnivore; large earthworms, prawns, mussel, whitebait, large sinking carnivore pellets once acclimatised. Breeding: Viviparous; litters of 4–12 pups; cooler temperatures (22–24°C) may help trigger breeding condition. Compatibility: Keep with very large, peaceful fish; size means few tankmates suitable beyond large bichirs or arowana.