Forktail Rainbowfish (Pseudomugil furcatus)

Forktail Rainbowfish (Pseudomugil furcatus) — A Jewel of the Nano Aquarium

The Forktail Rainbowfish (Pseudomugil furcatus) is one of the most beautiful and sought-after nano fish in the freshwater hobby. Native to the clear, fast-flowing streams of Papua New Guinea, this diminutive rainbowfish dazzles with a stunning combination of golden-yellow body colouration, electric blue eyes, and elongated, forked fins edged in vivid yellow and white — a display that is nothing short of spectacular, especially when males are in full breeding colour.

Small Fish, Spectacular Display

At just 4–5 cm in length, the Forktail Rainbowfish is perfectly suited to nano and planted aquariums, yet its visual impact rivals fish many times its size. Males in peak condition extend their ornate forked fins and intensify their colouration in a constant, shimmering display of courtship — a behaviour that makes a mixed-sex group endlessly captivating to observe. The interplay of golden yellow, iridescent blue, and bright white creates a living jewel effect that transforms any aquascape.

Care Profile

• Scientific Name: Pseudomugil furcatus
• Origin: Papua New Guinea — clear, fast-flowing streams and rivers
• Size: Up to 4–5 cm
• Temperament: Peaceful; best kept in mixed-sex groups of 8 or more to encourage natural display behaviour
• Diet: Omnivore — accepts micro pellets, baby brine shrimp, daphnia, micro worms, and finely crushed flake food
• Water Temperature: 22–28°C
• pH: 7.0–8.0 (prefers neutral to slightly alkaline, well-oxygenated water)
• Tank Size: Suitable from 60L upward; benefits from good water flow and surface agitation
• Note: Keep with peaceful, similarly sized tankmates — avoid boisterous or fin-nipping species that may stress or damage their delicate fins

Aquascape Compatibility

The Forktail Rainbowfish thrives in planted aquariums with open swimming space, good water movement, and fine-leaved plants such as hornwort, java moss, and floating plants that provide cover and spawning sites. It pairs beautifully with other peaceful nano fish — small rasboras, tetras, corydoras, and dwarf shrimp — in a lush, naturalistic community setup. Its golden and blue colouration creates a stunning contrast against green planting.

Golden, glittering, and endlessly graceful — the Forktail Rainbowfish is the nano jewel that brings the colours of Papua New Guinea to your planted aquarium.