Gulper catfish

Care at a glance

Overview

The gulper catfish is a specialist ambush predator best kept alone in a species tank, since it will try to swallow almost any tankmate whole, even one close to its own length. It spends the day hidden among wood and hangs quietly in the water at night waiting for prey. Do not house it with fish small enough to eat, and handle it carefully around its spines. Feed it infrequently on large chunks of fish or whole feeder-sized items, and never overfeed, as it gorges and then rests for days. It needs a roomy tank around 360 liters or larger with plenty of cover.

In the wild

Asterophysus batrachus comes from slow, dark blackwater rivers of the Rio Negro and Orinoco systems in Brazil and Venezuela, where it lurks among submerged wood in dim, acidic conditions. Keep it warm at 22 to 28 degrees C with a soft, gently acidic pH of 6.0 to 7.5. Furnish deep shade with driftwood tangles and caves, use subdued lighting, and keep the flow gentle. Clean, stable water and a secure lid suit this quiet, retiring hunter.

Good to know

A driftwood catfish in the family Auchenipteridae, the gulper reaches about 25 centimeters and has a huge mouth, backward-pointing teeth, and an enormously stretchable stomach. It swallows prey head-first and whole, sometimes fish as large as itself, which then folds inside the distended belly. Like its relatives it fertilizes internally with a modified anal fin. Aquarium breeding is not recorded.

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 a stomach that stretches so far the catfish can barely swim afterward.

Related species

• Jaguar catfish

  Liosomadoras oncinus

  9.1 in (23 cm)65 gal (245 L)72–82°F (22–28°C)

• 

  Common woodcat

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• Bottlenose catfish

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• Midnight catfish

  Auchenipterichthys coracoideus

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• Pygmy driftwood catfish

  Trachelyichthys exilis

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• Oil catfish

  Centromochlus perugiae

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