Iridescent Shark
Pangasianodon hypophthalmus
The Iridescent Shark is not a true shark, but a highly active, schooling catfish native to Southeast Asia. While frequently sold as tiny juveniles, they are notorious 'tank busters' that grow to massive sizes. They are extremely skittish and easily spooked, often injuring themselves by crashing into aquarium glass. They are best suited for heated indoor ponds or massive custom aquariums.
Iridescent Shark At a Glance
Iridescent Shark Tank Requirements
Will Iridescent Shark fit in your tank?
Care guides tell you what Iridescent Shark needs, the next question is whether your tank can safely provide it. Test Iridescent Shark against your tank size, maintenance needs, and the fish you already keep before you buy.
Iridescent Shark Water Parameters
Iridescent Shark Temperament & Compatibility
Iridescent Shark Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard Adult
Fully grown adult form. Requires a massive footprint as they are continuous, fast swimmers that startle easily and have a very high bioload.
Same care requirements as the base species
Also known as: Wild Type, Regular
Juvenile (Grow-out)
Typical size sold in pet stores. They are schooling fish at this age but will grow incredibly fast. Purchasing them without a concrete plan for a 500+ gallon upgrade is strongly discouraged.
Differs in 3 traits from base species
Also known as: Baby Id Shark, Small Pangasius
Albino Adult
A common color morph lacking pigment, resulting in a white/pink body and red eyes. Has the exact same massive size, skittish behavior, and care requirements as the standard type.
Same care requirements as the base species
Also known as: Albino Id Shark, White Pangasius
Iridescent Shark Care Guide Summary
The Iridescent Shark, scientifically known as Pangasianodon hypophthalmus, belongs to the Catfish family group. Adults reach a maximum size of approximately 100 cm and have a fusiform body shape with a fast growth rate. Classified as mostly peaceful, this species primarily occupies the mid-level zone of the aquarium and produces a extreme level of biological waste.
To thrive, the Iridescent Shark requires a freshwater only aquarium with a minimum volume of 2000 litres and a tank length of at least 250 cm. Water temperature should be maintained between 22°C and 28°C, with a pH range of 6.5–7.5 and a general hardness of 2–20 dGH. A moderate water flow is preferred.
The Iridescent Shark is a rewarding species to keep, provided its core environmental needs are met. This species is available in 3 varieties: Standard Adult, Juvenile (Grow-out), and Albino Adult. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Iridescent Shark Habitat Setup
When setting up an aquarium for the Iridescent Shark, a moderate water flow best suits their natural preferences. Because this species occupies the mid-level zone, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement. Useful additions include smooth gravel or rounded substrate to protect their sensitive barbels. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Iridescent Shark Compatibility Notes
Classified as mostly peaceful, the Iridescent Shark is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten. Selecting tankmates that favour different water layers from the mid-level zone can help reduce competition and territorial overlap.
Who Iridescent Shark Is Actually For
Iridescent Shark is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide a keeper who can commit to a proper group of at least 3. It makes the most sense for a hobbyist who will actually build around its needs, especially smooth gravel.
The most common mistake is buying Iridescent Shark for looks first and only later discovering how its adult size, behavior, or bioload changes the whole tank plan. Another frequent problem is underestimating its social needs. A token pair or trio often behaves very differently from a real group.
Frequently Asked Questions About Iridescent Shark
How big does Iridescent Shark get?
Iridescent Shark (Pangasianodon hypophthalmus) typically reaches a maximum adult size of approximately 100 cm. They have a fusiform body shape and a fast growth rate.
What tank size does Iridescent Shark need?
A minimum aquarium volume of 2000 litres and a tank length of at least 250 cm are recommended for Iridescent Shark. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Iridescent Shark need?
Iridescent Shark thrives in freshwater only conditions with a temperature range of 22–28°C, a pH between 6.5 and 7.5, and a general hardness of 2–20 dGH. A moderate water flow is preferred.
Is Iridescent Shark peaceful or aggressive?
Iridescent Shark is classified as mostly peaceful with an aggression score of 3 out of 10. They are generally well-suited to peaceful community tanks.
Can Iridescent Shark live alone?
Yes, Iridescent Shark can be kept singly or in a group. They are flexible and adapt well to both setups.
Does Iridescent Shark have any special tank requirements?
Yes. Iridescent Shark benefits from smooth gravel (sensitive barbels) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Iridescent Shark need a lid on the tank?
Yes. Iridescent Shark is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- April 28, 2026
- Last updated
- April 28, 2026
- Issues or corrections?
- Contact the editorial team
Top Tank Mates for Iridescent Shark
These fish are strong compatibility matches for Iridescent Shark based on water preferences, temperament, adult size, and tank behavior.
Spotted Hillstream Loach
Gastromyzon punctulatus
Ideal Tank MatesRaspy River Stingray
Potamotrygon scobina
Ideal Tank MatesTandanus Catfish
Tandanus tandanus
Ideal Tank MatesGold Spot Pleco (L001 / L022)
Pterygoplichthys joselimaianus
Ideal Tank MatesApistogramma Marmor (Marbled Apisto)
Apistogramma erythrura
Ideal Tank MatesAlligator Pleco
Pterygoplichthys scrophus
Ideal Tank MatesPlants That Suit Iridescent Shark
These plants pair well with Iridescent Shark based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
African Onion Plant
Crinum calamistratum
Afzel's Anubias
Anubias afzelii
Amazon Sword
Echinodorus amazonicus
Anacharis
Egeria densa
Anubias Barteri
Anubias barteri
Ashy Pipewort
Eriocaulon cinereum
Fish Similar to Iridescent Shark
Shortbarbel Pangasius
Pangasius micronemus
A massive, highly active riverine catfish native to Southeast Asia. Like its cousin the Iridescent Shark, it is a nervous and skittish swimmer prone to panicking and injuring itself on tank glass. Due to its enormous adult size of up to 1 meter (39 inches), it is strictly suited for only the largest custom aquariums, indoor ponds, or public aquaria. It is an opportunistic predator that will consume any tank mate small enough to fit in its large mouth.
Spot Pangasius
Pangasius larnaudii
A massive, fast-swimming catfish native to the Mekong basin, recognizable by a distinct large black spot just above its pectoral fins. Like the Iridescent Shark, it is a 'tank buster' that grows well over a meter in length. They are easily startled and prone to panic-swimming into glass, requiring enormous tanks with smooth decor.
Pungas Catfish
Pangasius pangasius
A colossal riverine catfish native to the Indian subcontinent. While highly important for aquaculture, they are disastrous for home aquariums. They grow rapidly to enormous sizes (up to 150-300cm), are easily spooked (often resulting in them ramming the tank glass at high speeds), and will swallow any tank mate that fits in their massive mouths.
Pangasius nasutus (Long-Nosed Pangasius)
Pangasius nasutus
A massive riverine shark-catfish native to Southeast Asia. It is an extremely active 'tank buster' that reaches up to 90cm (3 feet) in length. They are easily startled, prone to panic attacks, and can severely injure themselves by smashing into the aquarium glass. Due to their immense adult size, they are strictly suited for massive custom aquariums or heated indoor ponds.
Chao Phraya Giant Catfish (Paroon Shark)
Pangasius sanitwongsei
An apex predator native to the Mekong and Chao Phraya basins. This true 'monster fish' is completely unsuitable for home aquariums. They grow to massive proportions, are highly active, and easily startled—often severely injuring themselves by crashing into tank walls. They possess a massive appetite and are highly piscivorous, consuming any tank mate that fits in their mouth.
Common Synodontis (False Upside Down Catfish)
Synodontis nigrita
A robust and adaptable African catfish often mistaken for the true Upside-Down Catfish (Synodontis nigriventris). Unlike its smaller cousin, S. nigrita grows quite large (up to 20-22cm) and adults rarely swim inverted. They are nocturnal scavengers that are generally peaceful towards larger tank mates, but their predatory nature means they will consume small schooling fish (like Neon Tetras) at night.