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Campylomormyrus tamandua

Worm-Jawed Mormyrid

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Last revised 2026Edit this page

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Campylomormyrus tamandua juvenile
Campylomormyrus tamandua juvenileJJPhoto

Quick factsEdit

Max size
400mm SL16in SL
Aquarium size
180 × 60cm72 × 24in
Temp
23–28°C73–82°F
pH
5.0–7.0
Hardness
0–10dGH

Difficulty3 of 8 measures

Moderate

How the rating is worked out

Space
very large tank
Water
flexible
Temp
flexible
Diet
unknown
Temperament
unknown
Social
unknown
Compatibility
unknown

Other demands

Each of these can raise the rating on its own, whatever the measures above say.

Hardiness
unknown
  • Needs a very large tank

Before you buy

  • Needs a tight-fitting lid as this species is known to jump

    If kept in a brightly-lit tank the fish will be skittish and may jump.

The worm-jawed mormyrid, Campylomormyrus tamandua, is a benthic mormyrid recorded from nine countries in West and Central Africa. It sometimes arrives among imports of the elephant fish, Gnathonemus petersii, but has both jaws extended into a beak-like shape. It needs pristine soft, acidic water, generally refuses standard foods and grows to 400 mm SL. Like other mormyrids it produces a weak electric field, used to navigate and to communicate.

Distribution

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It has a wide distribution, having been recorded in Cameroon, Nigeria, Democratic Republic of Congo, Ghana, Chad, Benin, Mali, Burkina Faso and Niger.

Inhabits dark, muddy and heavily-vegetated areas of rivers. It's primarily a benthic (bottom-dwelling) species.

Aquarium size

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Standard length
400mm SL16in SL
Aquarium base
180 × 60cm72 × 24in
Volume
~648litres~171US gal

A tank measuring at least 180 ∗ 60 ∗ 60 cm72 ∗ 24 ∗ 24 in - ~648 litres~171 US gal is needed for an adult specimen. Younger fish can be grown on in smaller tanks.

Maintenance

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This nocturnal species prefers a dimly lit tank, and floating plants are a good idea to diffuse the light further. Stones, roots and plants can all be used to provide shade and cover, too. If kept in a brightly-lit tank the fish will be skittish and may jump. A sand base is essential, as it will probe the substrate with its snout in the hunt for food. Filtration over peat will help to mimic its natural waters, as will creating some water flow in the tank.

Water conditions

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Temperature
23–28°C73–82°F
pH
5.0–7.0
Hardness
0–10dGH

Temperature: 23 – 28 °C73 – 82 °F

pH: 5.0-7.0

Hardness: 0-10°H

These recommendations come from this profile’s own figures. They contain affiliate links, so we may earn a commission.

It will take frozen and live foods such as bloodworm, brine shrimp, earthworms, tubifex etc. Dried foods are rarely, if ever taken.

Behaviour and compatibility

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C. tamandua doesn't mix well with other mormyrids, including its own kind, but can be kept with many other similarly-sized species that can look after themselves. It should not be kept with very fast-swimming fish however, as it will be easily outcompeted for food. Suggested tankmates include larger Synodontis catfish and peaceful cichlids. In such a community, it's best kept as a single specimen.

Sexual dimorphism

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Unknown.

Reproduction

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It almost certainly hasn't been bred in aquaria.

Notes

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C. tamandua is quite a rare fish in the hobby, but is imported occasionally. It's not a good beginner's fish as it requires pristine soft, acidic water conditions, will generally not feed on standard foods and attains a very respectable adult size. It's also sensitive to many aquarium medications. It can sometimes be found as a contaminant among imports of the much more common Elephant Fish, Gnathonemus petersii. Unlike this species, C. tamandua has both upper and lower jaws extended, giving the mouthparts a more beak-like appearance.

Like other Mormyrids, it produces a weak electric field using specially-adapted muscle tissue located towards the tail. It also possesses electroreceptors that allow it to receive electrical signals. Using these, it can sense the tiniest of disturbances in the electrical field surrounding itself and use these to navigate, even in total darkness. This is a useful skill when hunting prey or avoiding predators in the dark. What's most fascinating about this adaptation is that the fish also use it to communicate with each other and find partners.

Mormyrids also have relatively large brains, possessing the equivalent of a human brain in terms of relative size. There are 3 different types of electroreceptors that carry information to different parts of this, allowing them to distinguish between different species of fish and ascertain the sex of conspecifics in total darkness!