Ocellate river stingray

Potamotrygon motoro

Also known as Motoro stingray, Peacock-eye stingray, Ocellated freshwater stingray

FreshwaterFish

Ocellate river stingray (Potamotrygon motoro) — Raimond Spekking · CC BY-SA 4.0

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 6.0–7.5
Adult size: 19.7 in (50 cm)
Minimum tank: 264 gal (1,000 L)
Temperament: Mostly peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Difficult
Breeding: Hard
Rarity: Common
Origin: Native to the Amazon, Parana and other South American river systems, resting on sandy substrate in slow rivers and lagoons.
Family: Potamotrygonidae

Overview

This is an advanced fish that needs a wide, low tank rather than a tall one: a single adult with a disc around 50 cm needs a footprint giving at least 1000 litres. Keep pristine water at 24 to 28 C and pH 6.0 to 7.5, with powerful filtration and frequent large water changes, as rays are very sensitive to nitrate and metabolic waste. The tail barb is venomous, so handle with great care and never keep one where a sting is likely. Feed earthworms, prawns, mussel and fish.

In the wild

The ocellate river stingray is a flat, disc-shaped freshwater ray patterned with orange-ringed eyespots on a brown back. It spends most of its time gliding over sand or lying buried with only the eyes showing. It uses its wide disc to trap prey against the substrate before eating.

Good to know

Potamotrygon motoro carries one or more venomous serrated barbs on the tail that can inflict a very painful, medically serious sting. It is a livebearer that gives birth to small litters of fully formed pups. Freshwater rays are among the few sharks and rays that complete their entire life cycle in rivers.