TankBud

Gulper catfish

Asterophysus batrachus

FreshwaterFish

Gulper catfish (Asterophysus batrachus)
Imperial Tropicals · Used with permission

Care at a glance

Temperature
72–82°F
22–28°C
pH
6.0–7.5
Adult size
9.8 in
25 cm
Minimum tank
95 gal
360 L
Temperament
Aggressive
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
No record
Rarity
Very rare
Family
Auchenipteridae
Origin
Brazil, Venezuela

Overview

The gulper catfish is a specialist ambush predator for a large species tank. It is a fish for experienced keepers.

Did you know

The gulper catfish can eat prey nearly as long as its own body. It engulfs a victim head-first, and backward-slanted teeth plus the prey's own struggles work it down into the stomach. That stomach stretches so far the catfish can barely swim afterward.

Caring for the gulper catfish

Give the gulper catfish a roomy tank of at least 95 gal (360 L) with plenty of cover. Furnish deep shade with driftwood tangles and caves, use subdued lighting and keep the flow gentle. It spends the day hidden among the wood, and a secure lid belongs on top.

Keep the water clean and stable, warm at 72 to 82°F (22 to 28°C), and soft with a gently acidic pH of 6.0 to 7.5. Feed it infrequently on large chunks of fish or whole feeder-sized items. Never overfeed, because it gorges and then rests for days.

The gulper catfish is an aggressive ambush predator that hangs quietly in the water at night, waiting for prey. It will try to swallow almost any tank mate whole, even one close to its own length, so keep it in a species tank. It does not need company, though it can live with others of its own kind. Handle it carefully around its spines.

Like its relatives, it fertilizes internally with a modified anal fin. Breeding it in an aquarium is not recorded.

Good to know

The gulper catfish, Asterophysus batrachus, is a driftwood catfish in the family Auchenipteridae. It has a huge mouth, and a swallowed fish folds up inside its distended belly.

In the wild

The gulper catfish comes from slow, dark blackwater rivers of the Rio Negro and Orinoco systems in Brazil and Venezuela. It lurks among submerged wood there, in dim and acidic conditions.

Common questions

What size tank does a gulper catfish need?

A gulper catfish needs at least 95 gal (360 L). It spends most of its time in the bottom.

What temperature and pH does a gulper catfish need?

A gulper catfish is comfortable at 72–82°F (22–28°C) with a pH of 6.0–7.5.

What does a gulper catfish eat?

A gulper catfish eats large chunks of fish or whole feeder-sized items. Feed it infrequently and never overfeed, since it gorges and then rests for days.

How big does a gulper catfish get?

An adult gulper catfish reaches about 9.8 in (25 cm).

How does a gulper catfish breed?

A gulper catfish fertilizes internally, using a modified anal fin like its relatives. Aquarium breeding is not recorded.

Related species