Description

Species Background
The Koi Angelfish is a selectively bred color variety of the freshwater angelfish, Pterophyllum scalare, a species native to the slow-moving rivers and flooded forest systems of the Amazon Basin in South America. Over many generations of captive breeding, aquarists developed strains displaying striking combinations of white, orange, and black patterning that resemble the coloration of ornamental koi. Some individuals develop deeper orange or red coloration on the head and shoulders as they mature, which is why similar fish are sometimes marketed under trade names like “Red Koi” or “Red Devil” angelfish. Regardless of the trade name, they remain a color morph of the standard angelfish species.

Behavior and Temperament
Angelfish are semi-peaceful cichlids that typically coexist well with similarly sized community fish. They spend most of their time cruising the mid-water column and navigating through plants or décor. As they mature they may become somewhat territorial, especially if a breeding pair forms, but they are generally manageable in community aquariums with appropriate tankmates.

Adult Size
Adults typically reach about 6 inches in body length, with a total height of 8–10 inches when the dorsal and anal fins are fully developed.
Typical size sold: approximately 3 inches.

Water Parameters
Temperature: 76–82°F
pH: 6.0–7.8
GH: 3–12 dGH
KH: 2

Koi Angelfish are popular because they combine the graceful body shape and slow, elegant swimming style of classic angelfish with bold koi-style co–8 dKH

Diet
Koi Angelfish are omnivores and accept a wide range of prepared and frozen foods. A high-quality cichlid pellet or flake should serve as the staple diet, supplemented with frozen foods such as bloodworms, brine shrimp, or daphnia for variety and conditioning.

Tank Requirements
Angelfish benefit from taller aquariums due to their vertical body shape and extended fins. A minimum aquarium size of 29 gallons is recommended for a small group, though larger tanks provide more space and help reduce territorial behavior. Aquascaping with plants, driftwood, and vertical structures helps recreate their natural environment and provides visual barriers.

Why They’re Popularloration. Their striking patterns and adaptable nature make them a favorite centerpiece fish for planted aquariums and community tanks.