Pseudomugil gertrudae (Gertrude's Spotted Blue Eye Rainbowfish)

Background:

Gertrude’s Spotted Blue Eye Rainbowfish, Pseudomugil gertrudae, is a small and striking freshwater fish native to the slow-moving, heavily vegetated waters of Papua New Guinea and northern Australia. This species is distinguished by its translucent body, bright blue eyes, and elaborately spotted, fan-like fins edged in black and yellow. Growing to just 2.5–3.5 cm, this fish is an ideal choice for nano or planted tanks, where its peaceful nature and lively schooling behavior can shine. Its adaptability and captivating appearance make it a favorite among aquarists.

Care Requirements:

• Water Parameters:

  • Temperature: 23–28°C
  • pH: 6.0–7.5
  • Hardness: 5–15 dGH

• Diet:
  Gertrude’s Blue Eye Rainbowfish thrive on a varied diet of high-quality micro pellets, finely crushed flakes, and live or frozen foods such as baby brine shrimp, daphnia, and cyclops. Feed small portions 2–3 times daily to match their active metabolism and small size.

• Tank Setup:
  A minimum tank size of 40 liters is recommended for a group of 6 or more individuals. Provide a soft substrate and plenty of live plants such as Java moss, Hornwort, or floating plants to create shaded areas and mimic their natural habitat. Open swimming spaces are essential for their active schooling behavior. Subdued to moderate lighting highlights their translucent bodies and vibrant fin patterns. A gentle water flow is preferred, as they inhabit calm waters in the wild.

• Behavior:
  Gertrude’s Blue Eye Rainbowfish are peaceful, social fish that thrive in groups of at least 6 individuals. Males display their striking fins during courtship rituals, especially in the presence of females. They are active swimmers and prefer the mid-to-upper water column, often darting gracefully among plants.

• Tank Mates:
  Suitable tank mates include other small, peaceful species such as Ember Tetras, Green Neon Tetras, and Pygmy Corydoras. Small shrimp species like Cherry or Amano Shrimp also pair well. Avoid housing them with aggressive or fin-nipping species, as their delicate fins are easily damaged.

Care Tips:

Maintain excellent water quality with regular partial water changes, as Gertrude’s Blue Eye Rainbowfish are sensitive to poor conditions. Keep them in groups to reduce stress and encourage natural schooling behavior. Provide a densely planted environment to replicate their natural habitat and foster confidence. A varied diet of small, high-quality foods ensures their health and vibrant coloration.

Gertrude’s Spotted Blue Eye Rainbowfish is a gem for nano and planted aquariums, combining delicate beauty with active and social behavior. Its dazzling fins, bright blue eyes, and peaceful temperament make it a standout choice for aquarists seeking a harmonious and visually striking addition to their tanks.