🐟 General Overview Common Names: Gertrude Rainbowfish, Spotted Blue-eye Rainbowfish, Dwarf Blue-eye Scientific Name: Pseudomugil gertrudae Family: Pseudomugilidae Origin: Northern Australia, New Guinea, and surrounding islands Type: Small freshwater schooling...
Common Names: Gertrude Rainbowfish, Spotted Blue-eye Rainbowfish, Dwarf Blue-eye
Scientific Name: Pseudomugil gertrudae
Family: Pseudomugilidae
Origin: Northern Australia, New Guinea, and surrounding islands
Type: Small freshwater schooling fish
Temperament: Peaceful, active, and social
Found in slow-moving streams, swamps, and forest pools rich in vegetation.
Prefers shallow, clear waters with dense aquatic plants and leaf litter.
Naturally inhabits soft, slightly acidic to neutral water conditions.
Adult Size: 1.2–1.5 inches (3–4 cm)
Lifespan: Around 3–5 years in captivity with proper care
Tank Size: Minimum 10–15 gallons (ideal for small groups)
Aquascape: Heavily planted tank with fine-leaved plants (like Java moss, Myriophyllum, or Rotala)
Lighting: Moderate to bright (enhances colors and promotes plant growth)
Substrate: Dark substrate helps colors stand out
Flow: Gentle to moderate; they dislike strong currents
Tank Lid: Essential — they are excellent jumpers
Temperature: 24–28°C (75–82°F)
pH: 6.0–7.5
Hardness: 5–15 dGH
Water Quality: Clean, stable conditions are vital — sensitive to fluctuations
Type: Omnivorous (micro-predator)
Preferred Foods:
Live or frozen foods: daphnia, brine shrimp, micro worms, bloodworms
High-quality micro pellets or crushed flakes
Occasionally, algae-based foods for balance
Feed small amounts 2–3 times daily.
Temperament: Peaceful and active, ideal for community tanks
Social Behavior: Best kept in groups of 6 or more — males display their fins beautifully when showing off to females
Compatible Tankmates:
Small, peaceful fish like ember tetras, rasboras, neon tetras
Dwarf corydoras, otocinclus, small shrimp
Avoid large or aggressive species that could intimidate or eat them.
Type: Egg scatterer
Breeding Setup:
Use a separate breeding tank with fine plants or spawning mops
Males court females with fin displays and chasing
Females scatter adhesive eggs on plants or moss
Incubation: Eggs hatch in about 7–10 days
Fry Care: Feed newly hatched fry infusoria or liquid fry food, then baby brine shrimp
Continuous breeders — adults may spawn daily in good conditions.
Keep stable temperature and pristine water conditions
Perform weekly partial water changes (20–30%)
Provide a mix of plant cover and open swimming space
Avoid strong filters that create heavy currents
Observe for fin clamping or dull colors — signs of stress or poor water quality
Males have elongated, iridescent fins with bright yellow and blue colors, while females are smaller and less vivid.
Known for their fluttering fin movements, resembling butterflies underwater.
Perfect choice for nano or planted tanks — adds sparkle and movement without aggression.
Their beauty is most visible under natural or LED lighting that enhances their reflective scales.
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