Red Irian Rainbow (Glossolepis incisis)

Red Irian Rainbow — Glossolepis incisus

Crimson motion from New Guinea

The Red Irian Rainbow is pure energy wrapped in metallic red. Mature males develop an intense scarlet-to-crimson body that glows under bright lighting, contrasted by silver highlights along the flanks and translucent red fins. When kept in proper groups, their color deepens dramatically — especially during display — turning the entire school into a moving wave of red.

Native to Lake Sentani and surrounding waters of New Guinea, Glossolepis incisus is built for constant motion. Unlike slow, hovering species, these rainbows are active midwater swimmers that thrive in open lanes with strong oxygen levels. In groups, they flash and pivot together, bringing life and brightness to larger community aquariums.

Growing to 5–6 inches, they are bold but generally peaceful, making them excellent additions to larger planted tanks or peaceful predator displays where smaller fish are safe.

Aquarium Setup

• Minimum Tank Size: 75 gallons (larger preferred for full schools)

• Group Size: 6 or more recommended

• Substrate: Sand or fine gravel

• Flow: Moderate current preferred

• Décor: Open swimming space with plants or structure along edges

• Lighting: Moderate to bright (enhances red coloration)

• Filtration: Strong biological filtration required

• Oxygen: Well-oxygenated water preferred

Tank Mates

Best with peaceful to semi-assertive species:

• Larger tetras

• Peaceful cichlids (Severums, Eartheaters)

• Corydoras

• Peaceful plecos

• Other rainbowfish species

Avoid aggressive predators and fin-nipping species.

Water Parameters

• Temperature: 74–82°F (23–28°C)

• pH: 6.5–8.0

• Hardness: Soft to moderately hard

• Water Quality: Clean and stable conditions essential

Diet

Omnivorous:

• High-quality flakes or pellets

• Frozen brine shrimp and bloodworms

• Small insects

• Occasional vegetable matter