Iridescent Shark
Pangasianodon hypophthalmus
Pangasiidae
About
The iridescent shark is a Mekong river catfish sold at 5-8 cm that reaches 130 cm and 44 kg in the wild and comfortably tops 90 cm in captivity. It is arguably the most misplaced fish in the aquarium trade: a nervous, fast-swimming open-water shoaler with poor eyesight that panics in enclosed spaces and injures its snout against the glass. Seriously Fish puts long-term housing for a single adult at 450 x 180 x 180 cm, around 14,580 litres, and openly questions whether the species should be considered an aquarium subject at all. It lives twenty years or more, and an adult swallows any tankmate that fits. The wild population is IUCN Endangered, even as the species is farmed by the million for the food trade.
Care
Realistically a pond or public-aquarium animal, not an aquarium fish. Nothing under several thousand litres is honest housing; our gate is 10,000 L over a 450 cm footprint, still well below what Seriously Fish recommends. It needs a group, strong flow, very high oxygen, open swimming space and no hard decor to collide with.
Diet
Omnivorous: protein-heavy as a juvenile, increasingly vegetable-based as an adult. Small tankmates are simply food.
Tankmate compatibility
Avoid (271)
Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.
Telling males from females
What works for this species, most reliable first.
- Adult sizeA hint only · only across animals of the same age
In many cichlids, catfish and loaches one sex simply grows larger — usually the male, though there are well-known reversals.
Frequently asked questions
- What tank size does a Iridescent Shark need?
- A Iridescent Shark needs an aquarium of at least 10000 litres (2641.7 US gallons) with a footprint at least 450 cm (177.2 in) long — for this species, swimming length matters as much as raw volume.
- What water parameters does a Iridescent Shark need?
- Iridescent Shark does best at 22–28 °C (71.6–82.4 °F), pH 6.5–7.5 and a general hardness of 2–20 °dGH.
- What group size does a Iridescent Shark need?
- Iridescent Shark is a social species — keep a group of at least 5 so natural behaviour emerges and stress stays low.
- Is the Iridescent Shark suitable for beginners?
- Iridescent Shark is a demanding species best attempted with some experience — it needs stable, closely watched conditions to thrive.