Bring vibrant color and energetic movement to your planted aquarium with the Spotted Blue Eye Rainbowfish(Pseudomugil gertrudae). Known for their iridescent neon-blue eyes, delicate spotted fins, and lively courtship displays, these peaceful nano fish are a premier choice for aquascapers and community aquarium enthusiasts alike.

Origin & Natural Habitat

Pseudomugil gertrudae is native to northern Australia, the Aru Islands, and southern New Guinea. In the wild, they inhabit slow-moving, shallow freshwater habitats such as tea-colored blackwater creeks, vegetated billabongs, swamps,and rainforest streams rich in tannins, leaf litter, and dense aquatic vegetation.

Aquarium Parameters & Care

Blue Eye Gertrudae are hardy once acclimated to an established aquarium, though they require stable water conditions and gentle filtration.

• Scientific Name: Pseudomugil gertrudae

• Adult Size: 1.2 to 1.5 inches (3 to 3.8 cm)

• Water Temperature: 70°F – 82°F (21°C – 28°C)

• pH Range: 5.5 – 7.5 (prefers neutral to slightly acidic)

• Water Hardness: 5 – 12 dGH

• Minimum Tank Size: 10 Gallons (a 15–20 gallon tank is recommended for schools of 8 or more)

Tank Setup & Environment

To see their best colors and natural schooling behavior, house them in a heavily planted aquarium. Incorporate floating plants, driftwood, and Indian almond leaves to mimic their native blackwater conditions and diffuse strong overhead lighting. Because they are active surface-to-midwater swimmers accustomed to slow-moving waterways, ensure filtration provides good oxygenation without high current or turbulent surface flow. Keep a secure aquarium lid, as nano rainbowfish are agile jumpers.

Diet & Feeding

Pseudomugil gertrudae are micropredators with small, upturned mouths. Offer a diverse omnivorous diet consisting of micro-pellets, crushed spirulina flakes, and finely ground freeze-dried foods. To condition them for breeding and maximize coloration, supplement daily with live or frozen micro-foods such as baby brine shrimp (Artemia), daphnia,cyclops, and microworms.

Compatibility & Tank Mates

This nano rainbowfish is exceptionally peaceful and thrives best in a dedicated species setup or a community tank with docile companions. They must be kept in groups of at least 6 to 10 (ideally with more females than males) to encourage active shoaling and male fin-flaring displays.

• Ideal Tank Mates: Celestial Pearl Danios, Chili Rasboras, Ember Tetras, Pygmy Corydoras, Otocinclus,Neocaridina shrimp (Cherry shrimp), and freshwater snails.

• Avoid: Large, aggressive, or fast-feeding fish (such as large cichlids, barbs, or predatory catfish) that can outcompete them for food or view them as prey.

Breeding

Gertrudae Blue Eyes are continuous egg scatterers and relatively easy to breed in a planted aquarium. Males develop elaborate, extended dorsal and pectoral fins, which they display to females in a fluttering dance. Provide fine-leaf plants like Java Moss or a synthetic spawning mop near the surface. Females deposit a few adhesive eggs daily over several days. In a heavily planted setup with infusoria and biofilm, fry often survive alongside the adults; for higher yields,transfer the spawning mop or moss to a separate fry-rearing tank.