Iridescent Shark
Pangasianodon hypophthalmus
The Iridescent Shark (Pangasianodon hypophthalmus) is a peaceful fish that's best left to experienced keepers. Give it a tank of at least 15000 litres (3963 US gallons), water held at 72-79°F, and a pH of 6.5-7.5. Always keep a group of at least 3 - they feel safest in numbers.
Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.
Natural distribution
Southeast Asia
- East & Southeast Asia
Regional colours match the stocking calculator's origin map.
Iridescent Shark Tank Setup
Plan for at least 15000 litres (3963 US gallons) with soft sand or smooth, rounded gravel - sharp substrate wears down their delicate barbels. Keep the water at 72-79°F with a pH around 6.5-7.5. Always keep a group of at least 3 of their own kind - kept alone or in pairs they tend to turn shy, nippy, or wash out in colour. They grow to around 130 cm, so plan the tank size and filtration for a full-grown adult rather than the small juvenile you see in the shop.
What Do Iridescent Sharks Eat?
They're not fussy eaters - feed a varied diet, rotating good-quality dry, frozen, and gel foods rather than the same thing every day, and match the food size to their mouths.
Iridescent Shark Tank Mates
NOT a home-aquarium fish: sold at a few centimetres but grows to 1-1.3 m and 40 kg+, and needs a pond-sized system of many thousands of litres - no ordinary tank is big enough. A nervous, fast open-water shoaler that panics and injures itself on glass and decor in confined tanks. It also eats small fish; if you already have one, find a public aquarium or very large pond early and never release it into the wild. The Iridescent Shark is peaceful, which is the first thing to weigh up when you choose tank mates. It's predatory, so anything small enough to fit in its mouth will be treated as food rather than a companion. It's a shoaling fish, so settle a group of 3 or more of its own kind before adding anything else - a stressed, lonely fish is far more likely to nip or hide. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.
Are Iridescent Sharks Good for Beginners?
Not a sensible first purchase. Get the tank cycled, keep easier fish stable for a year, then revisit if you still want the extra work this species demands.
Iridescent Shark - frequently asked questions
What size tank do Iridescent Sharks need?
Iridescent Sharks need a tank of at least 15000 litres (3963 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.
How many Iridescent Sharks should I keep together?
Keep a group of at least 3. Iridescent Sharks are a shoaling species and become stressed, lose their colour, or hide when kept singly or in pairs.
What water parameters do Iridescent Sharks need?
Keep them at 72-79°F with a pH of 6.5-7.5, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.
What do Iridescent Sharks eat?
Iridescent Sharks are omnivores and aren't fussy eaters. Feed a varied mix of good-quality dry, frozen, and gel foods, and match the food size to their mouths. Feed small amounts once or twice a day, and remove anything they don't eat.
Are Iridescent Sharks good for beginners?
Iridescent Sharks are not a beginner species. They need precise conditions and consistent maintenance, so build experience with hardier fish before keeping them.
Common mistakes with Iridescent Sharks
- Underestimating tank size - the minimum footprint is 15000 litres (3963 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.
Building a community? Run the full list through the stocking calculator before you add anything else.
Great tank mates
Chosen from temperament, overlapping temperature/pH bands, plausible minimum tank footprints, and size versus yours in App-aquatic data. Hobby nuance always wins - verify stocking and temperament before purchasing.
Check Iridescent Shark against any other fish → Compares water parameters, predation risk, fin nipping and tank size, and draws both at life size.
Fish to avoid mixing with Iridescent Sharks
These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.
- AngelfishPredator - Angelfish will eat or injure smaller tank mates
- Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
- Colombian Shark CatfishPredator - Colombian Shark Catfish will eat or injure smaller tank mates
