fish · Cichlidae
Uaru
Uaru amphiacanthoides
Wild range: Amazon basin: along the Solimões–Amazon from the Rio Japurá to the Rio Tapajós, and the middle and lower Rio Negro (FishBase; Seriously Fish). Seriously Fish and Aquadiction also list Guyana, but Tropical Fish & Aquariums notes only a few records from there. (South America)
At a glance: Uaru care
Compiled reference information. Review the care notes and original sources below.
What temperature is listed for Uaru?
The compiled profile lists 27.0–30.0 °C for Uaru (Uaru amphiacanthoides). Check the original sources below for context and differing recommendations.
What tank size is listed for Uaru?
The profile lists a minimum tank volume of 75.0 US gallons (284.0 liters). Volume alone does not establish suitability; consider dimensions, group size and other inhabitants alongside the full care notes.
What pH is listed for Uaru?
The compiled profile lists a pH of 6.0–7.0. Review the cited care sources alongside the other water parameters in this profile.
Natural habitat
The uaru, or triangle cichlid, is a large, deep-bodied Amazon cichlid. Adults are gold-brown with a big dark triangular patch on the side and yellow-to-red eyes; juveniles are mottled grey-brown with pale spots. It grows to about 20–25 cm, eats mostly plant matter, and is surprisingly peaceful and social for its size. It needs warm, soft, very clean water and a large tank, and is assessed Least Concern.
Where they are found
Primary name Uaru amphiacanthoides Heckel, 1840, valid in ITIS (TSN 170043), FishBase and GBIF; it is the type species of Uaru. Junior synonyms (FishBase; GBIF) are aliased: Pomotis fasciatus Jardine, 1843, Uaru obscurum Günther, 1862 (also spelled obscurus) and Acara imperialis Steindachner, 1879 (also seen as Uaru imperialis). The only congener, Uaru fernandezyepezi (Venezuela; also reported from the Tocantins and Xingu), is a separate, rarely traded species and is not aliased; Heros severus and Hoplarchus psittacus are look-alikes. Size: FishBase and Seriously Fish give a maximum of about 25 cm SL; aquarium adults are usually 20–25 cm (Tropical Fish & Aquariums), and Fish Laboratory reports up to 30 cm. IUCN: Least Concern (assessed 2018, per FishBase).
Aquarium care
Keep a pair in at least 284 L / 75 gal (Fish Laboratory; Tropical Fish & Aquariums; aquarium.guide; AquariumTankmates); a group of 4–6 needs about 125 gal or more, and Underground Aquarium gives 125 gal as its minimum. Keep it warm and soft: 27–30°C, pH 6.0–7.0 and about 1–8 dGH (Seriously Fish; Aquadiction; Tropical Fish & Aquariums; AquariumTankmates). Seriously Fish and Aquadiction prefer very soft water up to about 5 dGH, especially for wild fish; farm-bred fish adapt to a slightly wider pH as long as it stays stable. It is sensitive to nitrate and organic waste, so use strong but gentle filtration and change a large share of the water every week; poor water is linked to hole-in-the-head disease (Fish Laboratory; Tropical Fish & Aquariums). Decorate with sand, bogwood and roots and expect soft plants to be eaten.
Feeding
Mainly a plant eater: wild fish eat a lot of plant matter plus invertebrates and even freshwater sponges (Seriously Fish; FishBase). Feed a vegetable-based cichlid pellet with blanched greens such as courgette, cucumber, lettuce or spinach, and add meaty foods like bloodworms or chopped shrimp a couple of times a week (Fish Laboratory; Tropical Fish & Aquariums). Remove uneaten vegetables within a few hours so they don't foul the water.
Compatibility
Peaceful and social: keep at least a pair, ideally a small group, and expect some squabbling when pairs form (Seriously Fish; Aquadiction; Tropical Fish & Aquariums). Tankmates must like the same high temperatures. Good choices include angelfish, discus, Heros, Geophagus and Satanoperca eartheaters, headstanders, silver dollars and sturdy tetras (Seriously Fish; Fish Laboratory). Avoid aggressive cichlids such as oscars, green terrors and red terrors, which bully it (Fish Laboratory).
Breeding
Hard to sex: there are no reliable external differences outside spawning, so buy a group and let a pair form (Seriously Fish; Fish Laboratory). Breeding fish darken to almost black. A pair spawns on a flat rock or bogwood in warm, very soft, acidic water (about 29–30°C, pH around 6); eggs hatch in about two days, and both parents guard the brood while the fry feed on their skin mucus, like discus fry (Seriously Fish; Fish Laboratory; FishBase). Wild-caught fish need water close to their natural habitat to breed; captive-bred fish are less fussy (Seriously Fish).
Sources
Compiled from multiple independent care sheets — not copied from a single site.