Famous for its astonishingly large mouth and highly expandable stomach, the Gulper Catfish is a fascinating 'monster fish'. It can and will consume tank mates that are equal to or even slightly larger than its own body size. While generally peaceful toward fish that are definitively too large to swallow, its extreme predatory capabilities mean it is best kept in a dedicated species tank or with heavily armored, oversized companions.
Gulper Catfish At a Glance
Gulper Catfish Tank Requirements
Will Gulper Catfish fit in your tank?
Care guides tell you what Gulper Catfish needs, the next question is whether your tank can safely provide it. Test Gulper Catfish against your tank size, maintenance needs, and the fish you already keep before you buy.
Useful setup supplies
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Gulper Catfish Water Parameters
Water care products
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Gulper Catfish Temperament & Compatibility
Gulper Catfish Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard / Adult
The fully grown adult form. Their extreme bioload and massive appetite require oversized, highly efficient filtration and strict feeding schedules to prevent water quality degradation.
Same care requirements as the base species
Also known as: Adult, Breeder
Juvenile (Grow-out)
Sold at a smaller size, but grows rapidly. Even as juveniles, their mouths are disproportionately massive. Never house them with fish you want to keep long-term if they can fit in the Gulper's mouth.
Differs in 4 traits from base species
Also known as: Baby, Juvenile
Gulper Catfish Care Guide Summary
The Gulper Catfish, scientifically known as Asterophysus batrachus, belongs to the Catfish family group. Adults reach a maximum size of approximately 28 cm and have a depressed body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the bottom and mid-level zones of the aquarium and produces a extreme level of biological waste.
To thrive, the Gulper Catfish requires a freshwater only aquarium with a minimum volume of 250 litres and a tank length of at least 120 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 6–7.5 and a general hardness of 2–15 dGH. A moderate water flow is preferred.
Due to its specialist needs, the Gulper Catfish is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard / Adult and Juvenile (Grow-out). 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.
Gulper Catfish Habitat Setup
When setting up an aquarium for the Gulper Catfish, a moderate water flow best suits their natural preferences. Because this species occupies the bottom and mid-level zones, the aquarium layout should prioritise open swimming space in the centre of the tank for free movement and sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, and driftwood, which can serve as both a hiding place and a dietary supplement.
Gulper Catfish Compatibility Notes
Classified as semi-aggressive, the Gulper Catfish 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 and ornamental shrimp are not safe companions. Selecting tankmates that favour different water layers from the bottom and mid-level zones can help reduce competition and territorial overlap.
Gulper Catfish Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Gulper Catfish.
75 Gallon Standard
90 Gallon Standard
125 Gallon Standard
150 Gallon High
180 Gallon Standard
350 Liter (120cm Deep)
Show 1 more tank size
Gulper Catfish Feeding & Diet Considerations
The Gulper Catfish is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided, will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups, will eat fry, so breeding efforts in the same tank are unlikely to succeed, and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition.
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Frequently Asked Questions About Gulper Catfish
How big does Gulper Catfish get?
Gulper Catfish (Asterophysus batrachus) typically reaches a maximum adult size of approximately 28 cm. They have a depressed body shape and a moderate growth rate.
What tank size does Gulper Catfish need?
A minimum aquarium volume of 250 litres and a tank length of at least 120 cm are recommended for Gulper Catfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Gulper Catfish need?
Gulper Catfish thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 6 and 7.5, and a general hardness of 2–15 dGH. A moderate water flow is preferred.
Is Gulper Catfish peaceful or aggressive?
Gulper Catfish is classified as semi-aggressive with an aggression score of 6 out of 10. They can work in community setups but may clash with certain tankmates.
Can Gulper Catfish live alone?
Yes, Gulper Catfish can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Gulper Catfish safe with shrimp?
No. Gulper Catfish is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Gulper Catfish have any special tank requirements?
Yes. Gulper Catfish benefits from sand (sifters), smooth gravel (sensitive barbels), and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Plants That Suit Gulper Catfish
These plants pair well with Gulper Catfish 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 Gulper Catfish
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Black Bullhead Catfish
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