Spotted Blue Eye Rainbow (Pseudomugil gertrudae)

The Spotted Blue Eye (Pseudomugil gertrudae) is a beautiful small freshwater fish known for its brilliant blue eyes, translucent body, and distinctive spotted fins. Mature males develop larger, more colorful fins and frequently display them to other males and females, creating an impressive and lively display in planted aquariums.

Peaceful, active, and social, the Spotted Blue Eye looks especially attractive when kept in a proper group. Its small size, graceful swimming behavior, and striking fin patterns make it an excellent choice for planted aquariums and peaceful community setups. Good water quality, a varied diet, and plenty of vegetation help encourage its best coloration and natural behavior.

What We Like About This Fish

• Brilliant blue eyes
• Beautiful spotted and patterned fins
• Impressive fin displays from mature males
• Peaceful and active community fish
• Small size ideal for planted aquariums
• Interesting social and display behavior
• Looks especially impressive when kept in a proper group

Recommended Tank Parameters

• Tank Size: Minimum 40 liters (10 gallons)
• Temperature: 24–28°C (75–82°F)
• pH: 5.5–7.5
• Water Hardness: Soft to moderate
• Water Flow: Gentle to moderate

A well-planted aquarium with open swimming areas provides an ideal environment for Spotted Blue Eyes. Fine-leaved plants, moss, floating plants, and other vegetation provide shelter and security, while open areas allow males to perform their attractive fin displays. A secure aquarium lid is recommended because these small, active fish can jump.

Care Guidelines

Diet: Omnivorous. Due to their small mouths, Spotted Blue Eyes should be offered appropriately sized foods such as high-quality micro pellets, finely crushed flakes, baby brine shrimp, daphnia, and other small frozen or live foods. A varied diet helps maintain healthy growth, vibrant coloration, and good fin development.

Social Behavior: Peaceful and social. Spotted Blue Eyes should ideally be kept in groups of at least 6, although larger groups encourage greater confidence and more natural behavior. Keeping several males can encourage their beautiful fin displays. They are best housed with similarly sized, peaceful tank mates that will not outcompete them for food.

Origin

Oceania – Northern Australia, New Guinea, and surrounding regions

Average Adult Size

Approximately 3–4 cm (1.2–1.6 inches)

Average Purchase Size

Approximately 2–3 cm (0.8–1.2 inches)

Schooling Fish

Yes. Spotted Blue Eyes are social group-oriented fish and should ideally be kept in groups of at least 6. Larger groups encourage greater confidence, natural social interactions, and more impressive male displays.

Shrimp Safe

Mostly yes. Spotted Blue Eyes are small and peaceful and can generally coexist with adult shrimp. However, newly hatched shrimplets may occasionally be eaten. Dense plants, moss, and other hiding areas can help protect young shrimp.

The Spotted Blue Eye (Pseudomugil gertrudae) is an excellent choice for aquarists looking for a small, peaceful, and visually distinctive aquarium fish. With its brilliant blue eyes, beautifully spotted fins, and fascinating male display behavior, this attractive species can become a standout feature in a mature, well-planted aquarium.