Blue Eye Gertrudae Rainbow (Pseudomugil gertrudae)

Blue Eye Gertrudae Rainbow (Pseudomugil gertrudae)

Blue Eye Gertrudae Rainbows, more accurately known as Gertrude’s Spotted Blue-eyes, are a small and highly attractive rainbowfish relative known for their bright blue eyes, fine yellow coloration, and beautifully spotted finnage. They are an excellent choice for peaceful nano and planted aquariums, especially for hobbyists who enjoy active, delicate-looking fish with constant movement and display behavior. This is a small species, with adults generally staying around 30 mm standard length, making them much better suited to smaller peaceful aquariums than larger rainbowfish species.  

At Legacy Line Aquatics, these fish are raised in a small-scale, care-first setup. My focus is on healthy fish, clean systems, proper nutrition, and attentive day-to-day care, so you receive fish I’d be confident keeping in my own fish room.

Why Hobbyists Love Blue Eye Gertrudae Rainbows

• Bright blue eyes and beautifully spotted fins
• Constant movement and active mid-to-upper water behavior
• Excellent choice for peaceful planted aquariums
• Small adult size makes them great for nano-style community setups
• Males display beautifully toward each other without the heavy aggression of larger fish  

Temperament & Behavior

Blue Eye Gertrudae Rainbows are peaceful, active schooling fish that do best in groups. Like other blue-eyes, they are most comfortable and display best when kept with their own kind, and males will spend much of their time sparring and displaying to one another. They do best in aquariums with plant cover, darker substrate or décor, and gentle water movement. Seriously Fish specifically recommends a heavily planted aquarium, ideally with floating vegetation to diffuse the light.  

They do best in tanks with:

• Heavy plant cover
• Floating plants or dimmer lighting
• Open swimming space
• Gentle flow
• Stable water quality and temperature  

Tank Size (Recommended)

• Small group: 10 gallons minimum
• Better long-term setup: 15 gallons+
• Larger groups or community setups: 20 gallons+ preferred

Water Temperature

• Ideal range: 72–79°F
• Stable temperature is more important than chasing an exact number  

Tank Mates (Good Choices)

Best tank mates are other very peaceful, small community fish that will not outcompete them or intimidate them.

Good tank mates may include:

• Small peaceful rasboras
• Small peaceful tetras
• Other peaceful blue-eye species
• Small Corydoras in properly planned setups
• Peaceful shrimp and snails in well-structured aquariums, with the understanding that very small shrimplets may not always be safe

Avoid:

• Large or boisterous fish
• Fin-nippers
• Aggressive cichlids
• Fast, highly competitive feeders that outcompete them at mealtime  

Feeding

Blue Eye Gertrudae Rainbows do best on a varied diet of very small foods. Because they are a small species, foods should be appropriately sized. Seriously Fish notes that they should be offered small live and frozen foods such as Artemia nauplii, microworm, Grindal worm, along with good-quality dried foods of a suitable size.  

Recommended foods:

• High-quality small flakes or micro pellets
• Live baby brine shrimp
• Frozen cyclops and other very small frozen foods
• Microworms and other appropriately sized live foods  

What You’re Getting from Legacy Line Aquatics

When you purchase from me, you’re getting fish raised in a small-scale setup where care and condition matter. I focus on:

• Fish health
• Clean systems
• Proper feeding, including high-quality prepared foods and appropriately sized live or frozen foods
• Careful day-to-day observation
• Strong overall condition

That matters, especially with smaller, more delicate community fish.

Local Delivery

• Delivery is available within an 80-mile maximum distance from Owensboro, Kentucky.
• $150 minimum order is required for delivery
• $25 delivery fee applies

Local Meet-Up

• Local meet-up is available.
• After order we will contact you by email, or through Facebook or Instagram Messenger.
• We will arrange a date, time, and public location to meet.

Shipping & Live Arrival

Live fish are shipped Monday–Wednesday (weather permitting) to reduce transit risk. Please review our How Shipping Works page and DOA policy before ordering.