Forktail blue-eye
Pseudomugil furcatus, the forktail blue-eye or forktail rainbowfish, is a small rainbowfish in the family Pseudomugilidae, native to clear coastal streams of eastern Papua New Guinea. It has a translucent yellow-green body, blue-ringed eyes, and yellow-edged fins, with the paired dorsal fins and forked tail that give it its name. It is a peaceful, active shoaling species best kept in groups, where males spread their fins in constant courtship display. It suits a peaceful community of small, gentle fish. It thrives in a well-planted aquarium with clean, well-oxygenated water and gentle flow, appreciating fine-leaved plants and floating cover. It is an omnivore taking small flakes, micropellets, and live or frozen foods such as daphnia and baby brine shrimp. It is a continuous egg-scatterer that deposits eggs among fine plants or spawning mops, and dedicated keepers can raise the fry with small live foods.
Water parameters
| Temperature | 22 – 26 °C |
|---|---|
| pH | 6.5 – 8 |
| Carbonate hardness (KH) | 4 – 12 °dKH |
| General hardness (GH) | 6 – 15 °dGH |
Tank & stocking
| Minimum tank volume | 60 L |
|---|---|
| Volume budget per individual | 6 L — adds up with tank-mates |
| Minimum group size | 8 individuals (shoaling) |
“Minimum tank volume” is a reasonable floor, not an absolute limit. The per-individual budget is used by the Aqua app to estimate how heavily a tank is stocked.
Frequently asked questions
What size aquarium does Forktail blue-eye need?
Provide at least 60 litres for a small group to keep Forktail blue-eye in good conditions.
What water parameters does Forktail blue-eye need?
A temperature of 22–26 °C, pH 6.5–8.
Is Forktail blue-eye peaceful or aggressive?
Its temperament is peaceful.
What does Forktail blue-eye eat?
Its diet: omnivore.
How many Forktail blue-eye should be kept together?
It is a social species: keep a group of at least 8.
How big does Forktail blue-eye get?
Around 5 cm as an adult.
Is Forktail blue-eye suitable for beginners?
Care level: intermediate.
Planning a tank with Forktail blue-eye?
AquaTender turns these parameters into live advice: it checks whether your tank is big enough, how heavily it's stocked, and whether your fish are compatible — then tracks water tests, photos and maintenance for you.
Fish from the same biotope
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