Geophagus Megasema 4cm

Overview

Geophagus megasema is a handsome eartheater from the upper Madeira basin, with a large dark flank spot, iridescent blue-green scale rows and red-edged fins that develop with age. It spends its day sieving mouthfuls of sand for food, a peaceful and absorbing behaviour. Native to Bolivia and western Brazil, it suits keepers with a large, sandy soft-water tank for a group.

• Adult Size: Around 17–18 cm (7 in)
• Lifespan: 8–10 years

Origin

• Native to: Upper Río Madeira: Mamoré and Guaporé, Bolivia and Brazil
• Habitat: Sloping sandy margins with roots, rocks and leaf litter

Feeding

• Diet: Omnivorous; benthic sifter
• Preferred Foods: Fine sinking granules, bloodworm, tubifex, brine shrimp, daphnia, spirulina
• Feeding Habits: Three or four small portions daily rather than one

Tank Mates

• Best with: Own kind in groups, larger tetras, angelfish, peaceful Amazon cichlids
• Avoid: Fish small enough to swallow, aggressive cichlids, competing bottom sifters

Aggression & Behaviour

• Temperament: Generally peaceful outside breeding
• Territoriality: Dominance hierarchy within a group; pairs guard sites

Experience Level

• Difficulty: Intermediate
• Challenges: Needs sand, a large group and low nitrate

Water Parameters

• Water Type: Freshwater, soft and slightly acidic
• Temperature: 22–30°C (72–86°F)
• pH: 5.5–7.5
• Hardness: 1–15 dGH
• Flow: Slow to moderate
• Tank Size: Minimum 600 litres for a group of five to eight

Final Notes

Buy a group of five or more so a natural hierarchy forms and no single fish is bullied. A fine sand substrate is essential; gravel can damage gills and block feeding. It is a biparental mouthbrooder, with the female holding eggs and fry, and sexing young fish is difficult, so let pairs form from the group. Rooted plants will be dug up; attach plants to wood. Clean, stable water keeps it glowing.