Forktail Rainbowfish

The Forktail Rainbowfish (Pseudomugil furcatus) is one of the most energetic and charismatic nano fish you can add to a community tank, males sporting vivid yellow fins, striking blue eyes, and a deeply forked tail, constantly fanning their pectoral fins upward in elaborate “wing-flash” displays aimed at females and rival males alike. Growing to just 5 cm, they’re native to the lowland rainforest streams of Papua New Guinea and full of personality from the moment they’re introduced.

Keep at least six, but a group of 8–10 is where their social theatrics really come alive. They prefer a pH of 7.0–8.0 with moderately hard to hard water (GH), and as fish from oxygen-rich, fast-moving streams, they do best with good surface agitation and solid water movement to keep them at their vibrant best.

Avoid slow-moving or long-finned tank mates that might be stressed by their constant activity, and steer clear of anything predatory. They occupy the top-to-middle water column and are fast, enthusiastic feeders, small floating or slow-sinking foods like baby brine shrimp, daphnia, crushed flakes, and micro worms suit them perfectly. A spectacular, active nano fish for community tanks in South Africa.