Angelfish

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: may nibble soft.

Feeding

Easy to feed. Takes flake, pellets, frozen bloodworm, brine shrimp, mysis, freeze-dried foods, and live anything offered. In the wild the diet runs to small fish, fry, shrimp, worms, mosquito larvae, and surface insects. Two or three small meals a day, varied between dry and frozen, suits them. Overfeeding causes bloating and the usual water-quality problems.

Compatibility

• Can be kept in a community, but the choice of tankmates matters. The mouth is larger than it looks, and any fish small enough to fit will eventually be eaten. Neons start disappearing once the angels reach around 7 to 8 cm; cardinal tetras buy a little extra time because they are slightly larger, but the outcome is the same
• Reliable tankmates are species too big to be swallowed or too peaceful to provoke. Bottom dwellers like corydoras and bristlenose plecos, mid- and upper-water schoolers such as rummynose, congo, harlequin rasboras and similar medium tetras, peaceful gouramis, and dwarf cichlids that stay near the substrate (Bolivian and German blue rams, keyhole cichlids, several apistos) all work in the right tank size
• Fin nippers ruin the long fins. Tiger barbs and the more aggressive tetras are the usual culprits. Larger or aggressive cichlids should also be kept out
• Small shrimp are food
• Around a spawning site, a pair turns into a problem and will charge anything that comes near, including fish much larger than themselves

Origin and habitat

Wild angelfish are South American, occurring through much of the Amazon basin in Peru, Colombia, and Brazil, plus the smaller systems on the Guiana shield. Confirmed records cover the Ucayali, Solimoes, and main Amazon, the rivers of Amapa state in Brazil, the Oyapock in French Guiana, the Essequibo in Guyana, and Suriname. A very similar form turns up in the Orinoco; it interbreeds with the Amazonian fish and is told apart only by having paired thinner stripes instead of single broad ones. The genus Pterophyllum holds three species: this one, the taller-bodied altum (Pellegrin, 1903), and leopoldi (Gosse, 1963). The genus name is built from Greek roots meaning roughly 'leaf-fin' for the long triangular dorsal, and the species epithet means 'ladder-like' in Latin, after the vertical dark bars on the body. Schultze (writing in Lichtenstein's catalogue) put the species into the genus Zeus when he first described it in 1823, and Heckel set up Pterophyllum in 1840 to hold it. Natural habitat is calm, vegetated water on the floodplain, sometimes clear and sometimes silty; the disc-shaped body is built for slipping between plant stems and submerged roots, and the fish hunt small prey from those tangles. Pairs are monogamous and care for their eggs and fry, spawning on a flat vertical surface such as a broad leaf or a piece of submerged wood. Body length reaches around 15 cm. The species was first bred in captivity in the United States during the late 1920s and early 1930s. Wild imports are uncommon now; nearly all aquarium fish are captive-bred, much of the volume coming out of Asia and Eastern Europe, in dozens of selectively bred colour and finnage strains. IUCN Least Concern.

Breeding

Forms long-term monogamous pairs. Because the fish picks its own partner, the usual approach is to raise a group of juveniles and wait for pairs to form rather than introduce two random adults. A pair will clean a flat vertical surface (broad leaf, slate, length of PVC, tank glass) and lay eggs in tidy rows on it, with reports ranging from roughly 100 eggs up to several hundred per spawn and occasional clutches approaching a thousand. Both parents fan the eggs, pick off the ones that have fungused, and guard the area. Hatching takes around 48 to 60 hours depending on temperature, and the wrigglers spend several more days stuck to the spawning surface absorbing their yolks before they swim freely, generally five to seven days after the eggs were laid. First food is newly hatched brine shrimp. Many modern aquarium strains have lost a lot of the parental instinct through generations of artificial selection, and first-time or tank-raised pairs often eat their own eggs or fry, especially if they are disturbed or hungry. If a pair repeatedly eats its eggs, the simplest answer is to remove the spawning surface and incubate the eggs separately with gentle aeration and a drop of methylene blue to keep fungus at bay. Mated pairs that get on with the work tend to spawn every couple of weeks and can stay bonded for years; a surviving fish whose mate is lost sometimes refuses to pair again.

Common problems

Hole-in-the-head, the small pits and lateral-line erosions associated with poor husbandry, is recorded in this species and is often linked to the hexamitid flagellate Spironucleus vortens. The starting point for treatment is cleaning up water quality and diet; metronidazole is added in more advanced cases. Like most cichlids, angels do not handle a creeping nitrate level well, so keeping up with water changes matters more than it does for hardier community fish. Newly bought angels are commonly susceptible to ich, and bacterial fin rot turns up whenever water quality slips. Wild-collected stock and live foods occasionally introduce internal parasites that cause slow wasting in a fish that is still eating; quarantine new stock and culture live food carefully.

Bioload

Further reading

• Why your angelfish ate your neons
• Blackwater tanks: replicating acidic jungle streams
• Setting up a breeding tank