Geophagus altifrons

Geophagus altifrons takes its name (high forehead) from its steep, high forehead profile. Every scale on its gold-bronze body shines turquoise; there are blue lines on the cheeks, a dark spot in the middle of the body and fins with reddish edges. In mature fish the tips of the fins grow longer.

It is one of the large, peaceful species in what is known as the "surinamensis group" of the genus Geophagus. The species in this group are very similar to each other and are often confused in the trade; altifrons is one of the most common.

In Brazil it lives in the clearwater tributaries that flow into the Amazon from the south (such as the Xingu, Tapajós and Tocantins) and in the lakes connected to them. It moves in groups over sandy shallows and catches insect larvae and small crustaceans by sifting the sand.

• Volume: At least 400 liters and 180 cm of length for a group of 4–6.
• Substrate: Fine, rounded sand is essential; leave a large open sand area.
• Decor: Roots and large stones along the edges. Plants attached to roots and hard-leaved species hold up; because it sifts the sand, small foreground plants get damaged.
• Water: Soft, slightly acidic and clean water; a 30–50% water change every week. It is sensitive to nitrate.
• Light: Moderate to dim light; floating plants reduce shyness.

Omnivorous. Use small sinking granules and tablets as the staple; vary the diet with frozen bloodworms, brine shrimp, mysis and vegetable-based food. Because it feeds by sifting the sand, the food needs to fall to the bottom. Give 2–3 small meals a day.

A calm and social fish. A hierarchy forms within the group, but serious fighting is rare. Its sand-sifting behavior is constant and a pleasure to watch.

Good companions: Severum, uaru, festivum, angelfish, Satanoperca species, large tetras, plecos, corydoras.

Avoid: Aggressive Central American cichlids, gravel substrate, small shrimp.

Kept as a group of at least 4, preferably 6 or more. A fish kept alone becomes skittish. Over time a pair splits off from the group and guards a small area during breeding.

It is a delayed mouthbrooder. The pair lays its eggs on a cleaned stone; when the eggs are about to hatch or after they hatch, the larvae are taken into the parent's mouth. Even after the fry become free-swimming, they take refuge in the mouth when danger threatens. The fry are fed brine shrimp nauplii.

• Hole-in-the-head disease (HLLE): Common with high nitrate and poor water conditions.
• Gill and mouth irritation: On coarse substrate.
• Intestinal problems: With a monotonous diet and coarse foods.

There is no reliable way to tell the sexes apart from the outside. Males are usually larger, with a more pronounced forehead hump and fin extensions. A reliable distinction is made by the papilla.