Fish

Freshwater Angelfish

Pterophyllum scalare · also called angelfish, freshwater angelfish

Not Evaluated carnivoreomnivore Rivers & wetlands Rainforest

A freshwater angelfish is a cichlid that has been squeezed tall and thin, all height and trailing fins, so it can drift vertically between the drowned branches of the Amazon floodplain. It looks serene, and it is one of the oldest favourites in the aquarium hobby, but it is an ambush predator that will eat any tankmate small enough to swallow, and a breeding pair turns its corner of the tank into a fortress.

Overview

The freshwater angelfish, Pterophyllum scalare, is a South American cichlid of the slow, warm, plant-choked waters of the central Amazon. It is not related to the marine reef fish also called angelfish. Its deep, disc-shaped body and long fins let it slip between submerged stems and hang still while it stalks small fish and invertebrates.

A tall fish that pairs off

Angelfish grow up peaceful in a group, then sort themselves into monogamous pairs that pick a vertical surface, clean it, and take turns fanning and guarding the eggs and fry. A settled pair spawns every week or two. Because they swim and spawn vertically, they need a tall tank — at least ~45 cm deep — and a bonded pair becomes aggressive toward everything else.

In the aquarium

Kept since the early 20th century, the angelfish has been bred into silver, marble, gold, koi, black, and veil-tail forms unknown in the wild. Almost all sold are farm-raised domesticated scalare; the wild-caught trade centres on the taller altum angelfish of the Orinoco.

Status

Not evaluated by the IUCN. The common angelfish is widespread in the Amazon, is not a food fish, and is produced by the million on ornamental farms, so demand is met by captive breeding.

Freshwater Angelfish: common questions

Can angelfish live with neon tetras?

It is a classic pairing that often works but carries a real risk. Angelfish and small tetras come from the same waters and suit the same warm, soft, slightly acidic tank, and in a well-planted aquarium with a large school of tetras the combination can look superb and stay peaceful for years. The problem is that an adult angelfish is a natural predator of small fish and will eat any tankmate that fits in its mouth, and a full-grown angelfish can just fit an adult neon. Keepers who run the mix successfully add the angelfish young so it grows up with the school, keep the tetras in a big group so no single fish is singled out, and feed the angelfish well. Cardinal tetras, being slightly larger, are a safer choice than neons.

How can I tell a male angelfish from a female?

It is genuinely difficult outside of breeding, and even experienced keepers get it wrong. Males and females look almost identical, both with the same tall body and long fins, and the often-cited clues, a steeper forehead or larger size in males, are unreliable. The dependable method is to watch a group grow up and see which fish pair off, then look at the breeding tubes that both sexes extend just before spawning. The female's tube is shorter, wider, and blunt, pointed slightly forward, while the male's is longer, narrower, and pointed. If a pair produces eggs that never develop, it may be two females that have bonded, which happens when no male is present.

Why is my angelfish attacking the other fish?

Usually because it has paired up and is defending a nest site, or because it has outgrown its tankmates. Angelfish are peaceful as juveniles but become territorial cichlids as adults, and a bonded pair preparing to spawn will drive all other fish, including other angelfish, away from their chosen corner, chasing and nipping. A single dominant angelfish in too small a tank may also bully. The fixes are space and grouping. Keep angelfish either as a single pair, or in a group of five or more in a large tall tank so aggression is spread out, avoid keeping three or four where one gets picked on, and give plenty of tall plants and wood to break up sightlines.

How big do angelfish get and how long do they live?

A common aquarium angelfish reaches about 15 cm long and, with its fins, up to 20 cm or more tall, and the altum angelfish is larger still. They grow quickly for the first year and are close to full size by 18 months. A healthy angelfish in good conditions lives around 10 years, and 12 to 15 is possible, which is long for a popular aquarium fish and means buying one is a real commitment. Longevity depends heavily on tank size, water quality, and diet, and veil-tail and heavily inbred fancy strains tend to be less robust and shorter-lived than standard-finned fish.

Sources & further reading

Written by HideShark Editorial Team · reviewed by HideShark Science Desk. Published September 11, 2026. Last updated September 11, 2026.

Quick facts

Scientific name: Pterophyllum scalare
Diet: A stalking predator of the flooded forest, eating small fish, fish fry, insect larvae, worms, crustaceans, and other invertebrates picked from among submerged roots and plants, and in the aquarium taking flake, pellet, frozen and live bloodworm, brine shrimp, and small feeder organisms, while often hunting the fry of its own tankmates
Not a marine angelfish: The freshwater angelfish of the aquarium trade is a South American cichlid in the genus Pterophyllum and is unrelated to the bright reef fish also called angelfish, which are marine species in the family Pomacanthidae, the two groups sharing only a common name and a laterally flattened body
Built tall for the flooded forest: The angelfish has an extremely deep, narrow, disc-shaped body with long trailing dorsal, anal, and pelvic fins, a shape that lets it slip vertically between the drowned branches and plant stems of the Amazon floodplain and hang almost motionless while it stalks prey, and its silver body with dark vertical bars breaks up its outline among the stems
Pairs for life, more or less: Angelfish form lasting monogamous pairs that choose each other from a group, defend a territory together, clean a leaf or vertical surface, and take turns fanning and guarding the eggs and then the wriggling fry, and a settled pair will spawn again every week or two, though a pair that fails repeatedly may split up
A century in the aquarium: The angelfish has been kept and bred in home aquaria since the early 20th century and is one of the defining ornamental fish, and generations of selective breeding have produced many forms, including all-silver, marbled, gold, koi, black, blushing, and the veil-tail with greatly extended fins, most of which never occur in the wild
Three wild species: The genus contains the common angelfish Pterophyllum scalare, the taller and fussier altum or deep angelfish Pterophyllum altum from the Orinoco, and the small Pterophyllum leopoldi, and most aquarium angelfish are domesticated scalare or scalare hybrids rather than wild-type fish
They need height, not just length: Because of its shape and its habit of swimming and spawning vertically, an angelfish needs a tall aquarium, at least around 45 cm deep, and tends to be stressed and stunted in a shallow tank, and a group of young fish will usually sort itself into pairs that then become aggressive toward the others
Range: The Amazon river basin of Brazil, Peru, Colombia, and the Guianas, in slow, warm, often tannin-stained blackwater and clearwater, among the submerged roots, fallen branches, and dense aquatic plants of floodplain lakes, flooded forest, and quiet river margins, with related species in the Orinoco basin, plus feral populations established in parts of the United States and Asia from aquarium releases.
Conservation status: Not Evaluated ≈ The common angelfish has not been formally assessed by the IUCN. It is widespread through the central Amazon basin, is not targeted by food fisheries, and is produced in enormous numbers on ornamental fish farms in Southeast Asia, Florida, and eastern Europe, so the aquarium demand is met almost entirely by captive breeding rather than wild capture. Wild populations face the same broad pressures as other Amazon floodplain fish, chiefly deforestation, changes to the flood cycle from dams, and pollution, while the wild-caught trade focuses mainly on the altum angelfish from the Orinoco, where collection is regulated in the wild