TankBud

Iridescent shark

Pangasianodon hypophthalmus

Also known as Iridescent shark catfish, Sutchi catfish, Siamese shark, Striped catfish

FreshwaterFish

Iridescent shark (Pangasianodon hypophthalmus)
(c) Gannu03, some rights reserved (CC BY-SA) · cc-by-sa

Care at a glance

Temperature
72–79°F
22–26°C
pH
6.5–7.5
Adult size
39.4 in
100 cm
Minimum tank
528 gal
2,000 L
Temperament
Mostly peaceful
Social behavior
Schooling
Swim level
Bottom
Difficulty
Difficult
Breeding
No record
Rarity
Common
Family
Pangasiidae
Origin
Native to the Mekong and Chao Phraya river basins of Southeast Asia.

Overview

The iridescent shark is a mostly peaceful schooling fish that grows far too big for almost every home tank. It is really a fish for a pond or a public aquarium, and for experienced keepers only.

Did you know

The biggest welfare problem for iridescent sharks is not care difficulty. It is the gap between the silvery 5 cm juvenile in the shop and the meter-long adult it becomes. That gap is why so many end up rehomed or dead.

Caring for the iridescent shark

Be honest about the size before you buy an iridescent shark. Only take one on if you can house an animal this big for its 15 to 20 year life. It needs a huge, calm tank of at least 528 gal (2,000 L), long and with lots of horizontal swimming room.

Poor eyesight and a nervous streak make it prone to panic. It bolts at sudden movement and often injures itself against the glass or lid, so keep its surroundings dim and calm. Give it a gentle current, with water at 72 to 79°F (22 to 26°C) and a pH of 6.5 to 7.5.

It is not aggressive, but it will swallow anything bite-sized. It is a schooling fish, so keep it in a group rather than alone.

Good to know

The iridescent shark, Pangasianodon hypophthalmus, belongs to the family Pangasiidae. In the wild it grows up to 130 cm and over 40 kg. It is farmed by the million for food across Southeast Asia, usually sold under the name basa or swai.

In the wild

The iridescent shark is a big-river fish that roams the open channels of the Mekong and Chao Phraya in loose shoals. It is an active swimmer that covers long distances and feeds along the bottom.

Weekly picks

Tank mates

The iridescent shark is a mostly peaceful, schooling species that keeps to the bottom. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does an iridescent shark need?

An iridescent shark needs at least 528 gal (2,000 L). It spends most of its time in the bottom.

What temperature and pH does an iridescent shark need?

An iridescent shark is comfortable at 72–79°F (22–26°C) with a pH of 6.5–7.5.

How big does an iridescent shark get?

An adult iridescent shark reaches about 39.4 in (100 cm).

Does an iridescent shark need a group?

Yes. An iridescent shark is a schooling species and should be kept in a group, not singly.

Related species