Variety of Angelfish

Koi angelfish

Pterophyllum scalare

One of 9 varieties of Pterophyllum scalare · See all varieties →

FreshwaterFish

Koi angelfish (Pterophyllum scalare) — The Wet Spot Tropical Fish · Used with permission

Varieties · Pterophyllum scalare

See all 9 →

Care at a glance

Temperature: 75–86°F; 24–30°C
pH: 6.0–7.5
Adult size: 5.9 in; 15 cm
Minimum tank: 53 gal; 200 L

Temperament: Mostly peaceful
Social behavior: Social
Swim level: Middle
Difficulty: Easy
Breeding: Substrate spawner
Rarity: Very common
Family: Cichlidae

Overview

The koi angelfish has an orange crown and patches of black. It is easy to care for and mostly peaceful in a tall community tank.

Did you know

The koi angelfish cannot make its own orange pigment. Carotenoids are taken in with food and stored in the skin, so a koi's crown deepens or pales with condition. Two fish carrying identical genes can end up looking nothing alike.

Caring for the koi angelfish

A koi angelfish needs a tall tank of at least 53 gal (200 L), because its body grows taller than it is long. Give it vertical structure with driftwood and broad-leaved plants. It spends most of its time in the middle of the tank.

Warm water suits it, at 75 to 86°F (24 to 30°C) and a pH of 6.0 to 7.5. Feed a varied diet of quality flakes or pellets with frozen bloodworms and brine shrimp.

Koi angelfish are mostly peaceful and get along alone or in a group, but they remain cichlids. Small tetras and other tiny fish can end up eaten. Avoid fin-nippers too.

Koi angelfish are substrate spawners. A pair lays its eggs on a broad leaf or slate, then fans them and picks off any that go bad. A bonded pair defends its spawning site.

Koi are graded on how much orange sits on the head and how the black is placed, and heavy orange costs more. The orange can deepen or fade over months, so a young fish is a poor preview of the adult. Youngsters also show a pink patch over the gills. It usually clouds over as the gill plate turns opaque with age, and its loss is not a fault.

Good to know

The koi angelfish's double dose of stripeless leaves the top pigment layer translucent. That is what lets the orange layer underneath show through at all. Gold marble supplies the black, and because the dose shows, the amount of black tracks how many copies the fish carries. Koi pairs throw mostly koi, though a Gm/g parent can also pass on the plain gold allele. The placement of black and orange never repeats.

In the wild

The koi angelfish is a two gene combination rather than a single mutation, and no wild fish looks like it. It pairs gold marble at the dark locus with a double dose of stripeless, written Gm/Gm S/S or Gm/g S/S. Who first put the two together is not recorded, so koi is best treated as a hobby line of uncertain origin.

Weekly picks

Tank mates

The koi angelfish is a mostly peaceful, social species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator