Butter Catfish (Ompok bimaculatus)

Butter Catfish overview

Butter Catfish (Ompok bimaculatus) is a large Asian sheatfish for experienced aquarists with the space to plan ahead. It is a sleek, soft-bodied catfish with long barbels, a fast predatory feeding response and an adult size that makes it unsuitable for small community aquariums. This K730 listing is for the XL Butter Catfish .

Quick facts

Natural habitat and behaviour

Ompok bimaculatus is recorded from quiet, shallow and often turbid waters such as rivers, canals, sandy streams, floodplain habitats and inundated fields. In the aquarium this translates into a preference for cover, dimmer areas and open turning room rather than a bright, crowded display.

This species is not a small bottom cleaner. It is an active, long-bodied catfish that uses its barbels to locate food and will treat small fish as prey. It can look peaceful because it does not constantly harass tank mates, but that should not be confused with being safe with small tetras, rasboras, guppies or shrimp.

Aquarium size and layout

Choose this fish only if the aquarium is already large enough, or if a larger upgrade is genuinely planned. The animal should be able to turn without bending tightly, retreat from bright light and feed without smashing into decor. Strong filtration and oxygenation are important because large catfish produce a meaningful bioload.

Water parameters

The most important point is stability. A large predatory catfish in an undersized or immature tank can deteriorate quickly because waste levels rise and stress increases. Mature filtration, consistent maintenance and careful feeding are more important than chasing a narrow number.

Feeding

A varied meaty diet keeps the fish in better condition than one repeated food. Do not rely on live feeder fish; they add disease risk, poor nutrition and unnecessary stress. Smaller meals are easier on the aquarium than heavy overfeeding.

Compatibility

Butter Catfish should be treated as a specialist large predator. The safest display is a spacious large-fish community where every animal has enough room and no tank mate is small enough to become food. Avoid mixing it into a standard tropical community tank.

Arrival and acclimation

Large catfish can be easily startled after transport. Give the fish a quiet settling period, keep the aquarium covered and avoid repeated netting or unnecessary disturbance.

Size planning and long-term suitability

The most common mistake with this species is buying it for the size it is today rather than the size it can become. A young or recently imported Butter Catfish may look manageable, but the body length, speed and turning radius all increase as it grows. Plan the adult aquarium before purchase, especially if the fish is being added to a display that already contains expensive or delicate tank mates.

This is why the listing describes the fish as difficult rather than simply unusual. The care challenge is not fragile water chemistry; it is long-term space, feeding control, waste management and safe tank mate selection.

Common mistakes to avoid

Do not add Butter Catfish to a new aquarium, a small mixed community, or a tank built around tiny schooling fish. Do not assume a peaceful daytime posture means small fish are safe overnight. Do not feed large portions every day just because the fish responds strongly to food. Overfeeding a large catfish can damage water quality quickly, especially in warm aquariums with heavy stocking.

Also avoid sharp decor, narrow caves and unstable rockwork. A startled catfish can move quickly and injure itself if the layout has tight gaps or abrasive surfaces. Smooth wood, broad open retreats and a clear swimming lane make a much safer setup.

Who should choose this fish?

K730 is best for an aquarist who already keeps larger fish and understands the space, food and filtration needed by a predatory catfish. It is not a beginner clean-up crew fish and not a substitute for smaller peaceful catfish such as Corydoras. The right keeper will value its sleek body shape, nocturnal character and impressive size; the wrong setup will make it difficult to keep well.

When available, livestock orders are packed carefully for UK delivery and covered by our Live Arrival Guarantee where the delivery requirements are followed. First-time customers can use WELCOME10 where eligible. Check the stock status before planning a delivery date.

Useful next steps

For smaller community choices, browse Corydoras catfish. For other specialist catfish, see the freshwater catfish range. If you are building a large aquarium, compare filtration and hardscape in our aquarium accessories, or continue browsing freshwater fish.