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Trematocranus placodon

Snail-Crusher Hap

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Last revised 2026Edit this page

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Trematocranus placodon juvenile
Trematocranus placodon juvenileJJPhoto

Quick factsEdit

Max size
250mm SL10in SL
Aquarium size
150 × 38cm60 × 15in
Temp
24–28°C75–82°F
pH
7.6–8.8
Hardness
10–25dGH

Difficulty4 of 8 measures

Moderate

How the rating is worked out

Space
very large tank
Water
flexible
Temp
needs a steady temperature
Diet
unknown
Temperament
unknown
Social
one male with several females
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

The snail-crusher hap, Trematocranus placodon, is a large cichlid endemic to Lake Malawi, where it inhabits shallow water. A molluscivore, it feeds mainly on snails, crushing their shells with specially developed pharyngeal teeth. It suits the larger Malawian community but is not often seen for sale. Males are territorial and aggressive towards one another.

Distribution

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It inhabits shallow water, and is usually found around or in beds of Vallisneria

Aquarium size

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Standard length
250mm SL10in SL
Aquarium base
150 × 38cm60 × 15in
Volume
~257litres~68US gal

150 ∗ 38 ∗ 45 cm60 ∗ 15 ∗ 18 in - ~257 litres~68 US gal.

Maintenance

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Set up the aquarium with piles of rocks arranged to form caves, large areas of open water for swimming and preferably a sandy substrate. Planting with Vallisneria in dense patches would simulate the natural habitat of this species. There should be no strong current in the tank.

Water conditions

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Temperature
24–28°C75–82°F
pH
7.6–8.8
Hardness
10–25dGH

Temperature: 24 – 28 °C75 – 82 °F

pH: 7.6-8.8

Hardness: 10-25°H

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

Will accept most foods offered, and a varied diet of live, frozen and dried foods suits this species. Some snails should also be included in the diet when possible.

Behaviour and compatibility

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Unless the tank is very large, it is probably best in a species setup, as the fish are territorial, and males can command large territories. In bigger aquaria it can be combined with other large haps, such as Fossorochromis rostratus, Cyrtocara moorii, or even Frontosa.
Male fish are aggressive towards one another and only one should be kept in tanks of under 72" in length. Several females should be kept per male.

Sexual dimorphism

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Adult males are slightly larger and far more colourful than females.

Reproduction

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Not easy. Polygamous maternal mouthbrooder. The breeding aquarium should be at least 60" in length and furnished as suggested above. The addition of some large areas of open substrate to provide potential spawning sites and areas of planting with Vallisneria are recommended. A pH of 8.0-8.5 and a temperature between 25 – 27 °C77 – 81 °F are ideal. A breeding group of one male and 3-6 females is recommended.

When ready, the male will choose a spawning site by digging a depression in the substrate. These can be very large and the male will maintain and defend this as his territory. He will display around his chosen spawning site, showing intense colour, and attempt to entice females to mate with him. When a female is willing, she will approach the spawning site and lay her eggs there, allowing the male to fertilise them before picking them up in her mouth.
She will carry the brood of up to 100 eggs for around 3 weeks, before releasing the free swimming fry. She will not eat during this period and can be easily spotted by her distended mouth. If a female is overly stressed, she may spit out the brood prematurely or eat them, so care must be taken if you decide to move the fish in order to avoid fry predation. Some breeders artificially strip the fry from the mother's mouth at the 2 week stage and raise them from that point as this usually results in a larger number of fry.

The fry are large enough to accept brine shrimp nauplii from the day they are released.

Notes

Edit

An ideal species for the larger Malawian community but one not often seen for sale. In nature, it is a molluscivore, feeding primarily on snails. It has specially developed pharyngeal teeth, which can crush and grind the shells of these animals with ease. Several other species were originally assigned to the genus but currently, only 3 species of Trematocranus exist, most having been reclassified as Aulonocara or Alticorpus.

Distribution

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