Água doceIntermediária
Geophagus megasema — Megasema Eartheater (Geophagus megasema)

Megasema Eartheater

Geophagus megasema

The 'Large Spotted Eartheater' (18-20 cm). Eartheater cichlid of formidable beauty and moderate size, endemic to the Rio Madeira. It stands out, as the scientific name suggests, for a titanic black 'blotch' on the flank, disproportionately vast compared to other Geophagus. Wonderfully peaceful towards other species, it requires very fine sand, high temperatures and crystalline waters. Classic biparental oral incubator breeder.

Temperatura da água

24 - 28 °C

Valor de pH

6 - 7.5

Tipo de água

Água doce

Nível do tanque

Parte inferior

Tamanho adulto

20 cm

Volume mínimo do tanque

>= 180 L

Grupo mínimo

>= 1

GH

2 - 12 dGH

KH

1 - 6 dKH

TDS

40 - 240 ppm

Condutividade

63 - 375 uS/cm

Descrição da espécie

Geographical Origin and Habitat: Endemic species of the Guaporé River basin (Bolivia and Brazil). Lives in rivers with moderate currents and boundless bottoms of light sand or clay to sift.
Taxonomy and Morphology: Megasema Eartheater (Geophagus megasema). Robust but elegant South American cichlid. Belonging to the "surinamensis" group, it is distinguished by a gigantic ("mega") ocellar spot ("sema") on the flanks and an imposing muscular profile.
Social Behavior: Distinctly gregarious fish; keeping singles or pairs leads to chronic shyness. To mitigate inter-male aggression, they need to be kept in schools of at least 5-8 specimens. Dominants develop nuchal humps.
Coloration and Sexual Dimorphism: Coppery/sand background, with the unmistakable (very wide) black spot on the flank. The fins are a cascade of turquoise, red and golden lattices with very long filaments at the end of the tail in mature males.

Cuidado, criação e companheiros de tanque

Aquarium Setup: A 150 cm (60 inches) tank is needed. Only true absolute rule: the bottom must be a thick layer of pure sand (sugar-grade, or washed building sand). Do not insert medium quartz: they spit it out, but they flay their gills.
Diet and Feeding: Geophagous ("earth eater"). Takes shovelfuls of sand, swallowing them and sifting with the food through the gills. Provide a fast-sinking omnivorous cichlid pellet and rain down bloodworms and brine shrimp.
Water Quality: Despite their size, they are sensitive to an excessive load of nitrates. So as not to slow down their growth or develop the hole-in-the-head scourge (HITH), change at least 40% of water a week with excellent siphoning.
Compatibility and Cohabitation: Formidable pairings with schools of large South American tetras (Penguin tetra, Buenos Aires tetra) which reassure the group by staying on the surface. Excellent with Loricariids, terrible and unsuitable with biting cichlids like Jack Dempsey or Midas.
Aquarium Breeding: Larvophile mouthbrooders. The pairs lay on a clean flat stone, but as soon as the young hatch from the egg (2-3 days), both parents put them in their mouths in turns protecting them for over 2 weeks.
Risks and Diseases: Sharp gravel and nitrate accumulations cause the onset of the lethal Hexamita (Hole-in-the-head disease) on the head. Food competition with fast surface fish (e.g. sharks or large barbs) makes them lose weight dramatically.

Origem e distribuição geográfica

Endemic species of the Guaporé River basin (Bolivia and Brazil). Lives in rivers with moderate currents and boundless bottoms of light sand or clay to sift.

Origem

Amazônia, Orinoco e GuianasAmérica Central e Caribe

Perfil de peixe

Temperamento
Semi-aggressive
It is a mild-mannered cichlid. Unprovoked aggression is very rare. It is a wonderful centerpiece fish.
Dieta
Omnivore
It is an eartheater. Feed sinking pellets and frozen bloodworms. A fine sand substrate is mandatory.
Expectativa de vida
10 years
Tamanho adulto
20 cm
Proporção sexual
Pair
Keep them in groups. This diffuses natural aggression. Pairs will emerge as they mature.
Frequência de alimentação
Twice daily
It constantly sifts the sand. Feed multiple small meals daily. This mimics natural continuous foraging.
Carga biológica
High
This fish produces a high bioload. Robust biological filtration is essential. Frequent water changes are necessary.
Fluxo
Stagnant
It originates from riverine environments. It prefers moderate water flow. Provide resting areas with calm water.
Risco de salto
Yes
It is a bottom dweller. It can jump if startled. A secure lid is always recommended.
Reprodução
Oviparous
Many are mouthbrooders. Parents fiercely guard eggs and fry. Breeding pairs form naturally over time.
Compatibilidade e companheiros de tanque
Semi-aggressive
It is generally peaceful. It fits well in community tanks. It becomes territorial during spawning.
Nível do tanque
Bottom
It stays at the bottom. It continuously sifts the sand. A large footprint is required.

Modelos e parâmetros científicos

FishBase

Acesso aos dados científicos oficiais da espécie

FishBase v25.04Dados sincronizados em: 15/06/2026
Nível trófico
2,3 ± 0,1 se
Resiliência
Alta (menos de 15 meses)
Unicidade filogenética (PD50)
0.5
Relação bayesiana comprimento-peso
a = 0.02512, b = 3.02
VulnerabilidadeVulnerabilidade baixa (13 / 100)