Blue Whale Catfish (Siluriformes sp.) in a freshwater aquarium
Easy carePeacefulBottom dwellerSouth America / Africa

Blue Whale Catfish

Siluriformes sp.

The Blue Whale Catfish (Siluriformes sp.) is a peaceful fish that's easy to keep. Give it a tank of at least 265 litres (70 US gallons), water held at 72-79°F, and a pH of 6-7.8.

Care levelEasy
TemperamentPeaceful
Min tank size70 US gal
pH range6-7.8
Temperature72-79°F
Max size10.6 in (27.0 cm)
Captive lifespan12-20 years
SchoolingNo
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Captive lifespan reflects typical experience in a home aquarium, not maximum recorded age; genetics, sourcing, and care vary.

Natural distribution

Mostly South America / Africa

  • South America
  • Africa

Regional colours match the stocking calculator's origin map.

Blue Whale Catfish Tank Setup

Plan for at least 265 litres (70 US gallons) with soft sand or smooth, rounded gravel - sharp substrate wears down their delicate barbels. Keep the water at 72-79°F with a pH around 6-7.8. They grow to around 27 cm, so plan the tank size and filtration for a full-grown adult rather than the small juvenile you see in the shop.

What Do Blue Whale Catfish Eat?

They're bottom feeders, so give them sinking wafers, tablets, or frozen treats like bloodworm once the lights go down. Flakes that never reach the bottom leave them hungry even when the tank looks well-fed.

Blue Whale Catfish Tank Mates

Requires a large tank and good filtration. The Blue Whale Catfish is peaceful, which is the first thing to weigh up when you choose tank mates. At around 27 cm fully grown, it needs tank mates that can hold their own against its size and appetite. Before you buy, run your full stocking list through our stocking calculator. It weighs temperament, adult size, and water needs together, which a single species page can't do on its own.

Are Blue Whale Catfish Good for Beginners?

Reasonable early choice after cycling. Buy after the tank has stable ammonia and nitrite readings, not the same weekend you fill it.

Blue Whale Catfish - frequently asked questions

What size tank do Blue Whale Catfish need?

Blue Whale Catfish need a tank of at least 265 litres (70 US gallons). A bigger tank is always easier to keep stable, and gives them more room to settle in and behave naturally.

What water parameters do Blue Whale Catfish need?

Keep them at 72-79°F with a pH of 6-7.8, steady rather than chased to an exact figure. In a cycled tank, ammonia and nitrite should both read 0 ppm, with nitrate kept low through regular water changes.

What do Blue Whale Catfish eat?

Blue Whale Catfish are bottom feeders. Give them sinking wafers, tablets, and frozen foods that settle on the substrate, ideally after the lights go off. Feed small amounts once or twice a day, and remove anything they don't eat.

Are Blue Whale Catfish good for beginners?

Yes - Blue Whale Catfish are a reasonable beginner fish once the tank is cycled and parameters are stable. Add them after ammonia and nitrite read 0 ppm, not the same day you fill the tank.

Common mistakes with Blue Whale Catfish

  • Underestimating tank size - the minimum footprint is 265 litres (70 US gallons); impulse buying into a smaller tank leads to stress and shortened lifespan.

Building a community? Run the full list through the stocking calculator before you add anything else.

Fish to avoid mixing with Blue Whale Catfish

These well-known species are commonly sold alongside this fish but are not recommended tank mates - verify before purchasing.

  • OscarPredator - Oscar will eat or injure smaller tank mates
  • Pea PufferPredator - Pea Puffer will eat or injure smaller tank mates
  • Betta (Male)Predator - Betta (Male) will eat or injure smaller tank mates