Gymnogeophagus balzanii

Thanks to the large, rounded hump on their foreheads, mature male Gymnogeophagus balzanii look like no other cichlid. Their gold-bronze bodies are decorated with shiny blue lines and spots on the head and fins. Females are much smaller, plain gray-olive in color and have no hump.

It comes from the subtropical regions of South America; so, unlike tropical cichlids, it benefits from being kept in cooler water (18–20°C) for a few months in winter. In water that is constantly 28°C or warmer, its lifespan shortens and its colors fade.

It lives in the basin of the Paraguay and Paraná rivers, in Argentina, Paraguay, Brazil and Bolivia. It is found in the sandy-muddy, vegetated shallows of slow-flowing rivers and lakes. In the region the water temperature varies markedly between summer and winter.

• Volume: At least 200 liters and 100–120 cm of length for one male and 2–3 females.
• Substrate: Fine sand; it sifts the sand constantly.
• Decor: Roots, rounded stones and hardy plants along the edges; areas where females can hide.
• Heating: 24–26°C in summer, 18–20°C for a few months in winter. If room temperature is suitable, the heater can be switched off in winter.
• Water: A 30% water change every week; moderately hard water around neutral.

Omnivorous. Use small sinking granules and tablets as the staple; vary the diet with frozen bloodworms, brine shrimp, mysis and mosquito larvae. Reduce the amount of food during the cool period.

Generally a calm species. During breeding the male claims an area of sand, invites the females with showy fin-spreading displays and chases away rival males.

Good companions: Calm species that tolerate cool water: corydoras (such as paleatus), medium-sized tetras, Ancistrus, peaceful subtropical cichlids such as Cichlasoma portalegrense.

Avoid: Species that need constantly warm water, such as discus and altum angelfish, aggressive large cichlids, small shrimp.

A harem setup is recommended: 1 male and 2–3 females. More than one male can be kept in a large tank, but the dominant male suppresses the others and makes their colors fade.

It is a delayed mouthbrooder. The female lays the eggs in a pit or on a stone prepared by the male; about a day later she takes the eggs or the newly hatched larvae into her mouth. Incubation is mostly done by the female, and the fry stay in the mouth for around 2 weeks until they are free-swimming. The fry are fed brine shrimp nauplii.

• Constantly high temperature: Weakens immunity and shortens lifespan.
• Hole-in-the-head disease (HLLE): In poor water quality.
• Gill irritation: From coarse substrate.

Easy: the mature male is much larger, with a huge forehead hump, long fin tips and bright blue patterns. The female is small, has no hump and is plainly colored; the dark spot in the middle of her body is prominent.