Fish comparison
Forktail Blue-Eye vs Pacific Blue Eye
How the Forktail Blue-Eye and Pacific Blue Eye compare on care, size, water and temperament, and which fish suits your tank.
By Mike ElmiraUpdated
TL;DR, Forktail Blue-Eye vs Pacific Blue Eye
The Forktail Blue-Eye and the Pacific Blue Eye are close cousins, both in the Pseudomugil group, so at a glance they ask for a lot of the same things. Both are happy somewhere around 23 to 27 °C and pH 6.5 to 7.5, so a single tank can suit either one. Neither is harder than the other to keep, so the choice comes down to look and stocking rather than skill. Read the full care notes on each below and pick the one whose look and pace fit the tank you're building.
Group compatibility overview
Excellent fit
Every key parameter overlaps and no major conflicts surfaced.
3 notes
Temperature
- Forktail Blue-Eye23–27 °C
- Pacific Blue Eye18–28 °C
pH
- Forktail Blue-Eye6.5–7.5
- Pacific Blue Eye6.5–8
Hardness
- Forktail Blue-Eye5–15 dGH
- Pacific Blue Eye8–25 dGH
What to plan for
- Forktail Blue-Eye schools, stock at least 6You've planned for 1 forktail blue-eye. Forktail Blue-Eye need a group of at least 6 to feel safe and shoal naturally, below that they're stressed and lose colour. Dial up the count, or remove the species.
- Pacific Blue Eye schools, stock at least 8You've planned for 1 pacific blue eye. Pacific Blue Eye need a group of at least 8 to feel safe and shoal naturally, below that they're stressed and lose colour. Dial up the count, or remove the species.
- No bottom teamNo bottom-dwelling fish or shrimp. A small group of corydoras or a shrimp colony picks up leftover food and keeps detritus in check.
Full attributes
Every parameter, side by side| Parameter |  FishForktail Blue-EyePseudomugil furcatus |  FishPacific Blue EyePseudomugil signifer |
|---|---|---|
| Category | Fish | Fish |
| Origin | Papua New Guinea | Eastern Australia |
| Family | Pseudomugilidae | Pseudomugilidae |
| Temperature | 23–27 °C | 18–28 °C |
| pH | 6.5–7.5 | 6.5–8.0 |
| Hardness (dGH) | 5–15 | 8–25 |
| Flow rate | Low to Medium | Low to Medium |
| Min tank | 60 L | 60 L |
| Adult size | 4–5 cm | 3–5 cm |
| Difficulty | 2 / 5 | 2 / 5 |
| Lifespan | 2–3 yrs | 2–3 yrs |
| Diet | Micropredator | Carnivore |
| Water column | Mid to Top | Top to mid |
| Schooling | Yes | Yes |
| Plant safe | Yes | Yes |
| Shrimp safe | Yes (adult shrimp) | Yes (with adults) |
Frequently asked questions
Direct answers to the questions search engines and AI assistants surface most often about this species.
Can you keep Forktail Blue-Eye and Pacific Blue Eye together?
Yes. Their temperature and pH ranges overlap around 23 to 27 °C and pH 6.5 to 7.5, so one set of water conditions keeps both comfortable. Match group sizes and cover the usual planted-tank basics and they share a tank fine.
Which is easier to keep, the Forktail Blue-Eye or the Pacific Blue Eye?
They sit at the same care level, both beginner-friendly, so neither is the obvious beginner pick. The decision is really about the look you're after.
Do Forktail Blue-Eye and Pacific Blue Eye need the same water?
Close to it. Aim for 23 to 27 °C and pH 6.5 to 7.5 and you're in the shared sweet spot for both. Full ranges are in the table above.
What's the main difference between the Forktail Blue-Eye and the Pacific Blue Eye?
It comes down to look, size and pace rather than one being flatly better. The table above lays the numbers out row by row.