Bigtooth river stingray

Potamotrygon henlei

Also known as Black diamond stingray, Henlei ray, Tocantins ray

FreshwaterFish

Bigtooth river stingray (Potamotrygon henlei) — Christine Schmidt from Laurel, USA · CC BY 2.0

Care at a glance

Temperature: 75–82°F (24–28°C)
pH: 6.0–7.2
Adult size: 21.7 in (55 cm)
Minimum tank: 396 gal (1,500 L)
Temperament: Mostly peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Difficult
Breeding: Hard
Rarity: Rare
Origin: Native to the Rio Tocantins basin in Brazil, over sand and among rocks in clear, warm rivers.
Family: Potamotrygonidae

Overview

This is a large, expensive ray for experienced keepers only, with an adult disc around 50 to 55 cm that demands a very wide tank of at least 1500 litres. Keep spotless water at 24 to 28 C and pH 6.0 to 7.2 with heavy filtration and big, regular water changes. The tail barb is venomous, so treat the fish with respect and avoid risky tankmates. Feed a varied diet of earthworms, prawns, mussel and fish.

In the wild

The black diamond stingray, also called the bigtooth river stingray, is a striking ray with a near-black disc covered in fine white or cream spots. It is heavy-bodied and grows larger and thicker than most common rays. Like its relatives it rests on sand and ambushes prey from the substrate.

Good to know

Potamotrygon henlei is endemic to the Rio Tocantins in Brazil and is prized in the hobby for its high-contrast spotting. It bears live young and, like all river rays, carries a venomous tail barb capable of a severe sting. Spot number and size vary between individuals and are used by keepers to grade fish.