Cupid Cichlid

Biotodoma cupido is an eartheater that resembles the Geophagus species but stays much smaller. Its gray-gold body has a dark spot below the dorsal fin, a dark band running through the eye and shiny blue-green lines on the cheeks. In mature fish the rear tips of the dorsal and anal fins grow longer.

With its calm, peaceful nature it fits into the same aquarium as species such as angelfish and discus. On the other hand, it is sensitive to water quality and quickly loses its color and appetite in gravel-bottomed, dirty or hard water.

It lives on the sandy banks of slow-flowing rivers and in lakes of the Amazon basin. It catches small invertebrates by sifting the sand; the water is soft, acidic and warm.

• Volume: At least 200 liters and 100–120 cm of length for a group of 4–6.
• Substrate: Fine, rounded sand is essential.
• Decor: Roots, leaf litter, rounded stones and plants along the edges; a large open sand area in the middle.
• Water: Soft, acidic and very clean water; a 30% water change every week. Keeping nitrate low is important.
• Light: Dim light and floating plants reduce shyness and bring out the colors.

Omnivorous. Use small sinking granules and tablets as the staple; vary the diet with frozen bloodworms, brine shrimp, daphnia and mosquito larvae. Give 2–3 small meals a day.

Peaceful; apart from minor squabbles within the group, there is no fighting. It can be shy; next to active and aggressive tankmates it hides and falls behind in the competition for food.

Good companions: Angelfish, discus, medium-sized tetras, corydoras, otocinclus, dwarf cichlids (in a large tank), festivum.

Avoid: Aggressive Central American cichlids, large and fast-eating fish, coarse substrate, small shrimp.

A group of at least 4, preferably 6, is recommended. When a pair splits off within the group, it defends its breeding area, but this defense is moderate.

It is an open spawner. The pair lays hundreds of small eggs on a cleaned stone or in a pit in the sand. Both parents guard the eggs and fry. Breeding in the aquarium requires very soft and acidic water. The fry are fed brine shrimp nauplii.

• Sensitivity to water quality: Loss of appetite and color at high nitrate levels.
• Hole-in-the-head disease (HLLE): Common in eartheaters.
• Bacterial infections: After transport; quarantine is recommended.
• Sudden changes in values: Rapid changes in temperature and pH cause stress; bring new water to the same values as the aquarium beforehand.

Difficult to tell from the outside. Males are usually slightly larger and have longer fin extensions. A reliable distinction is made by the papilla.