Catfish

About Catfish

Large catfish belong to the order Siluriformes and are found across rivers and lakes worldwide, from the Amazon basin to Southeast Asia and Africa. They have a long history of being valued both as food and as ornamental fish by local communities, and remain consistently popular in the aquarium hobby. Their most distinctive physical feature is their long barbels — whisker-like sensory organs that detect subtle vibrations and chemical signals in the water. Body coloration and shape vary enormously by species, ranging from intricately spotted plecos to near-black, torpedo-shaped varieties. While generally timid and peaceful, they will instinctively prey on fish small enough to swallow, so careful tankmate selection is essential. Watching them explore at night or cautiously peek out from their hiding spots offers a unique observational experience unlike any other tropical fish. The opportunity to build a lasting relationship with such a commanding creature is, for many keepers, the greatest reward of large catfish keeping.

7 things to know before welcoming a Catfish

1. 1A Large Tank Is Essential

   Many large catfish grow to 60–100 cm or more as adults, requiring tanks of at least 150–200 cm in length. Even if they appear small at purchase, plan ahead and set up a tank sized for their full adult length from the start.

2. 2Robust Filtration Is a Must

   Large catfish eat heavily and produce significant waste, causing water quality to deteriorate quickly. Use high-capacity filtration such as combined external and canister filters, and perform water changes one to two times per week to maintain stable water conditions.

3. 3Nocturnal and Cave-Loving

   Most large catfish are nocturnal, spending daytime hours hidden under driftwood or inside caves. Providing adequate hiding spots reduces stress and encourages natural behavior. Evening and nighttime are the best times to observe them in action.

4. 4Be Careful with Tank Mates

   Large catfish may eat tank mates that fit in their mouth, so choosing appropriately sized companions is critical. Fish of similar or larger size are safer choices, and some aggressive species are best kept alone.

5. 5Water Temperature and Quality

   Most tropical large catfish prefer water temperatures of 25–28°C and are sensitive to sudden temperature changes. A pH of 6.5–7.5 (slightly acidic to neutral) suits most species, though requirements vary. Consider keeping a spare heater, as a malfunction can be fatal.

6. 6Feeding: Type and Quantity

   Large catfish are mostly carnivorous to omnivorous; feed them a balanced diet of sinking pellets, frozen bloodworms, and shrimp. Remove uneaten food promptly, and offer only what they can consume within one to two hours. During growth stages, feeding several times a week is often sufficient.

7. 7Understand the Long-Term Costs

   Initial costs including a large tank, powerful filtration, heaters, and lighting can be substantial, and ongoing expenses such as electricity and water bills will also rise. Some large catfish live 10–20 years or more, so creating a long-term care plan and budgeting in advance is essential.

Frequently asked questions about Catfish

Q.How large do large catfish typically grow?

A.Size varies greatly by species. Some, like the redtail catfish or tiger shovelnose catfish, can exceed 60–100 cm when fully grown. Always research the adult size of a species before purchasing.

Q.Can large catfish be kept with small fish?

A.Small fish that can fit in their mouths are at very high risk of being eaten, so keeping them together is generally not advisable. Choose tankmates of a similar or larger size to minimize this risk.

My catfish barely moves during the day — is that normal?

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