Lake Furnusu Rainbowfish

Lake Furnusu Rainbowfish ( Melanotaenia mairasi )

A rainbowfish endemic to Lake Furnusu in West Papua, Indonesia. It inhabits areas with dense aquatic vegetation and submerged roots, typically at depths of 2–3 meters or more. This species is listed as Critically Endangered due to its extremely restricted range.

• Maximum Size: Reaches approximately 7–10 cm (2.8–4 inches) total length.
• Appearance: Brownish to dark iridescent body with a prominent midlateral blackish stripe running from the eye to the caudal-fin base. Features narrow red stripes between scale rows and orange scale margins. Males tend to be darker with stronger iridescent blue and black tones, while females are generally yellower to orange.

Aquarium Care

• Tank Size: Minimum 40 gallons for a school.
• Water Parameters: 75–82°F (24–28°C), pH 6.5–7.5, soft to moderate hardness. Dense planting or cover is beneficial.
• Diet: Omnivorous. Accepts high-quality flakes, micro-pellets, frozen foods, and live foods such as brine shrimp and daphnia.
• Behavior: Peaceful schooling fish. Best kept in groups with suitable cover and swimming space.

IUCN Status: Critically Endangered (CR).