Southern Blue Eye Rainbowfish (Pseudomugil signifer)
The Southern Blue Eye Rainbowfish, Pseudomugil signifer, is a peaceful Australian blue-eye with a slim body, bright reflective eye, active shoaling behaviour and attractive yellow to clear fins that mature males use during display. Also known as the Pacific Blue-eye, Blue-eye or Southern Blue-eye, this adaptable small rainbowfish is ideal for mature planted aquariums, temperate-to-tropical community setups and carefully managed outdoor tubs in suitable weather. It is hardy when settled, but sensitive to sudden changes, so stable water quality and careful acclimation are important.
Key Features
- Peaceful and social fish, best kept in groups
- Distinctive bright eye and colorful fins in males
- Thrives in planted tanks with stable water conditions
- Adaptable to temperate-to-tropical environments
Specifications
| Feature | Detail |
|---|---|
| Scientific Name | Pseudomugil signifer |
| Common Names | Southern Blue Eye Rainbowfish, Pacific Blue-eye, Blue-eye |
| Size | Up to 5 cm (2 inches) |
| Temperament | Peaceful, shoaling |
| Water Temperature | 18–26°C (64–79°F) |
| Water pH | 6.0–7.5 |
| Hardiness | Hardy when acclimated properly |
FAQ
What is the ideal tank setup for Southern Blue Eye Rainbowfish?
They thrive in mature planted aquariums with stable water conditions and a group of at least 6 fish. A temperate-to-tropical setup with moderate lighting and soft substrates works best.
Are Southern Blue Eye Rainbowfish suitable for beginner aquarists?
They are suitable for experienced hobbyists who can maintain stable water parameters. Beginners should ensure consistent water quality and avoid sudden changes in temperature or chemistry.
Do males and females show different coloration?
Yes, mature males develop bright yellow to clear fins and a reflective blue eye used during display. Females are generally more subdued in color.

Blake Slater –
Added a group of Southern Blue Eye Rainbowfish to my planted tank. They are very active and peaceful, forming a nice shoal. The males show off their bright fins during the day, which is a pleasant sight. I keep the water stable and have not had any issues so far.
Isaac Sutherland –
These fish are beautiful and fit well in a community tank with other peaceful species. I noticed the males become more colorful as they mature. I do need to monitor water parameters closely, but overall, they are a great addition.
Karen Mathis –
I’ve kept them in a 60-liter planted tank with low lighting. They swim actively and don’t stress other fish. The eye color is striking, and the yellow fins stand out in the water. Very satisfied with the purchase.