What used to be called "the poor man's discus" by some... and bred by a select few, the Triangle Cichlids (there are actually two species) are well worth a second look and space-permitting, trials at raising, pairing, breeding and rearing their young. Like discus back in the sixties, Uaru's were all wild-collected and difficult to spawn and raise, and like Symphysodon, they too have become more facile in captive care and reproduction.
The genus name Uaru is derived from the native, uara aru, "resembling a (hand) mirror, likely in reference to the genus' pancake like shaped members. The specific name amphiacanthoides is the old name for the genus of tangs, Acanthurus, which these fishes resemble both physically and in their preference for vegetable foodstuffs. The common name of the "Triangle" refers to the large body shape of adults.
There are presently two described species of the genus Uaru, and possibly a third (this fish is sometimes imported into Europe, sold as the "orange-fleck Uaru").
The Triangle can reach a length of a foot in the wild... and might do so in captivity given enough space. A pair needs to be kept in at least an eighty gallon, with a 125 being better. Groups being reared for pairing need at least 125 gallons for development and spawning.
Water Chemistry & Physics:
Being found in the same waters as Symphysodon it is not surprising that Uaru's prefer the same sorts of water conditions. Low pH (about 5.0), softest of water (ideally 0.0 dKH), and warm temperatures (84-88). Now, these values are for wild-collected specimens (which are still at times imported... better to seek out captive-produced), and captive produced stocks are much more agreeable to more alkaline, harder, less tropical conditions... but if you're interested in maintaining your Uarus in ideal settings and possibly breeding them, targeting their original water quality is suggested. For folks with naturally hard, alkaline source water, blending in some portion from softened, deionized or reverse-osmosis water will lower alkalinity and pH. Chemical preparations can be added to lower these values further or peat moss added to your filter flow path. Uaru, like Discus are sensitive to metabolite build-up, hence, weekly water changes are suggested. Tropical temperatures in the mid-80's are de riguer.
This is a shy fish that does best in dimly lit settings with heavy use of driftwood and rooted plastic and possibly live floating plants (though they may eat them). Rooted plants are not suggested as these fishes are herbivorous as well as diggers. If you're interested in spawning, provide some hard horizontal material (slate, flower pot, roofing tile...) for their use.
Though not often done, Uarus can be kept with Angels and Discus, both types of fishes they are caught in the same habitat with in the wild (Sterba, 1962). More often you'll see them kept by themselves, perhaps with a loricariid catfish or two, maybe with some other easy going Central and South American cichlids like acaras or eartheaters. For larger fishes, Uaru's are not particularly aggressive or disagreeable to other fishes, and will generally ignore livebearers, small tetras and other community fishes. Oh, and this fish should not be kept individually, pairs or more make for much better-adjusted, outgoing (though still shy) Uarus.
Uaru accept all types of foods, but do provide more than dried prepared pellets, sticks and flakes... Meaty foods or mixes of beef heart, shrimps, and do include some blanched or cooked greenery (other than spinach) for their herbivorous nature, with vitamins... and occasionally live foods like glassworms, blackworms, earthworms, mealworms... really add to the color, growth and vitality of this fish. Without these non-dry foods your fish will not likely spawn.
Uarus are like discus in another way; both are contact feeders of their young. This situation is not obligatory though, and Triangle young can be reared apart from their parents. Triangle cichlids are difficult to breed and it's not easy to rear their young. Pairs are best "made" by rearing a group in a large system and allowing them to match up. The little morphological difference in their bodies, fins and urogenital structures is not easily discernible. It is suggested that if/when pairs take up spawning, that you leave them in place, with other fishes, as this species is a notorious egg eater... Do this for the first two, three spawning events and either move the breeding pairs to separate quarters, or utilize a system of removing the spawning medium and rearing the young away from adults. There are suggestions in the literature to cover the spawn with mesh held in place with suction cups, leave lights on... other techniques for preserving the eggs from parental ingestion.
Young hatch out in about four days and are too small to take newly hatched brine shrimp. Most breeders use either prepared liquid or dried fry foods or powdered (baker's) egg yolk fed several times a day as initial food. Growth is rapid if good water quality (changes) and adequate nutrition is applied, with young attaining some two inches in length in as many months.
Uaru are more than usually susceptible to the erosive condition called 'head and lateral line disease'. This pitted neuromast situation is largely resultant from poor nutrition and diminished water quality. Improving both through regular water changes, augmenting foods with multivitamins will reverse all but the most advanced cases.
As juveniles Triangle Cichlids can fall prey to external parasites, but they're much higher up the scale of resistance than most tropical fishes.
Uaru's are amongst the most regal and intelligent of aquarium fishes, ranking right up with Discus. Unlike their neighbors the Symphysodon, Triangles are far more hardy and eager eaters. A fish well-worth considering keeping for its beauty as well as potential earning from breeding, selling its young.
Johnson, Don. S. 1992. Spawning the "almost" discus. An alternative on breeding the uaru. AFM 12/92.
Leibel, Wayne S. 1997. Uaru. At one time called the "poor man's discus"- but not anymore. AFM 7/97.
Loiselle, Paul V. 1985. The Cichlid Aquarium. Tetra Press, Melle Germany.
Quarles, Jim. 1997. Uaru amphiacanthoides: the poor man's discus. TFH 3/97.
Sterba, Gunther. 1962. Freshwater Fishes of the World. Pet Library, Ltd. New York. pp. 832.