Not furry, but we like them anyway.

Iridescent Shark

Pangasianodon hypophthalmus (Sauvage, 1878)

Also called Iridescent shark catfish, Siamese shark catfish, Sutchi catfish, Striped catfish, Swai

SpeciesShort profile

From Southeast Asia: the Mekong, Chao Phraya and Maeklong river basins; introduced to other basins for fish farming.1 2

At a glance the quick version

Weightup to 44 kg1 2

Lengthup to 130 cm1 2

Sizegiant

Unsexed maximum recorded weight of 44 kg.

Shimmering, shark-like shape

Sociable schooling fish

Can gulp air thanks to a breathing swim bladder

1 2

Looks how to spot one

Large, streamlined, scaleless catfish

A torpedo-shaped catfish with a shark-like profile. Young fish shimmer and carry dark stripes along and below the lateral line, while big adults turn an even grey with darker fins.1 2

Coloursiridescent silver-grey (young)black lateral stripes (young)uniform grey (adult)dark fins1 2

Personality what they are like

A peaceful, schooling fish that is easily startled; calm surroundings help it settle.2

Daily activity how busy a day looks

A constant open-water swimmer that migrates long distances in the wild and needs a great deal of swimming room.2 1

Grooming and care the hands-on bits

Best suited to public aquariums or very large aquarium systems. FishBase advises against home aquariums and gives more than 150 cm as a bare minimum length; Wikipedia notes adults need a tank around 12 m long. Keep the setup calm to avoid sudden frights.1 2

Home where they are happiest

Very large tank or public aquarium exhibit. Water 22-26 C, pH 6.5-7.5, hardness about 2-29 dH.1 2

Food basics what goes in the bowl

An omnivore that eats fish, crustaceans and plant matter; a diet not too high in animal protein suits it.1 2

Company who they like around

Lives in schools and is happiest with others of its kind.2

The story where it all began

Described by Sauvage in 1878, this Mekong catfish became one of the most important farmed fish in Southeast Asia, sold worldwide as swai, basa or panga fillets. Small juveniles also entered the aquarium trade, where their silver sheen and shark-like shape earned the name iridescent shark.1 2

Fun facts for the dinner table

1
Despite the name it is a catfish, not a shark; the name comes from its shark-like look.2
2
Its swim bladder doubles as an air-breathing organ.2
3
Vietnam's pangasius exports were worth about US$1.8 billion in 2014.2
4
Wild fish migrate upstream to spawn in the flood season and drift back down as waters fall.2

Recognised by the official bits

IUCN Red List: Endangered (assessed January 2011)1
Taxonomy: Described by Sauvage in 18781
Family: Pangasiidae (shark catfishes)1

The care rhythm a typical week and year

A typical home-care rhythm for an Iridescent Shark. A starting point, not a vet's advice.

Feedingevery day
Water changeAbout 30 to 50% of the waterevery week
Water testevery week
Filter rinseevery 2 weeks

Owner questions the things everyone asks

How often should I feed my Iridescent Shark?

Feed your Iridescent Shark once daily. Furry Diary's starting plan suggests daily feeding. The exact amount depends on the food label and your vet's advice, as overfeeding can harm water quality. This active swimmer enjoys a varied diet.1 2 Pet Wiki plan

What does an Iridescent Shark eat, and what should it never eat?

This omnivore eats fish, crustaceans, and plant matter. Avoid a diet too high in animal protein. For specific foods and what to never offer, ask your vet or a good breeder.1 2

How much space does an Iridescent Shark need?

This fish needs a very large tank, at least 150 cm in length, and adults may require a tank around 12 meters long. It is best suited to public aquariums or very large home systems. Provide plenty of open swimming room.1 2

What temperature, light or water does an Iridescent Shark need?

Keep water temperature between 22-26°C, pH 6.5-7.5, and hardness 2-29 dH. Lighting needs vary; consult a vet or breeder for specific advice. This scaleless fish prefers calm surroundings.1 2

How often should I clean an Iridescent Shark's home?

Furry Diary's starting plan recommends weekly water changes of 30 to 50%, weekly water tests, and rinsing the filter every two weeks. Regular cleaning keeps the water quality stable for this sensitive fish. Pet Wiki plan

Can an Iridescent Shark live with others?

Yes, it is a peaceful schooling fish that thrives with others of its own kind. Keep it in a group to reduce stress. Avoid tankmates that may startle it.2

How long does an Iridescent Shark live?

Lifespan varies depending on care and environment. For accurate information, ask your vet or a good breeder.

Can I handle an Iridescent Shark?

It is best not to handle this fish. It is scaleless and easily startled, so handling can cause stress or injury. Enjoy watching it swim gracefully instead.2

Written from the sources on this page, a few checked guides (VCA, ASPCA, RSPCA) and Pet Wiki's own starting care plan. A friendly guide, not a vet's advice.

Redtail Catfish

Where this comes from

Every fact on this page has a numbered source. Spotted an error? [email protected].

FishBase: Pangasianodon hypophthalmus fishbase.seused for distribution, size, weight, water parameters, diet, IUCN, aquarium advice
Wikipedia: Iridescent shark en.wikipedia.orgused for other names, appearance, behaviour, aquaculture, fun facts, tank size

Checked 2026-09-30. Text is written in our own words from these sources.