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
From Southeast Asia: the Mekong, Chao Phraya and Maeklong river basins; introduced to other basins for fish farming.12
At a glance the quick version
Unsexed maximum recorded weight of 44 kg.
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.12
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.21
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.12
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.12
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.12
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.12
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 Furry Diary remembers it for you
A typical home-care rhythm for a Iridescent Shark. It is our own starting plan, not a vet's advice, and you can change every line in the app.
- Feedingevery day
- Water changeAbout 30 to 50% of the waterevery week
- Water testevery week
- Filter rinseevery 2 weeks
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Where this comes from
Every breed page shows where each fact comes from. If we got something wrong, sorry, we are pet people, not a science magazine. Tell us at [email protected] and we will fix it.
- 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.