Gertrude’s Spotted Blue-Eye Rainbowfish (Pseudomugil gertrudae)

Quick Overview of Gertrude’s Spotted Blue-Eye Rainbowfish

Gertrude’s Spotted Blue-Eye Rainbowfish (Pseudomugil gertrudae) is one of the most exquisite, sought-after micro-rainbowfish species in the aquatic hobby. Native to the shallow, heavily vegetated rain-forest streams, tea-colored swamps, and lily ponds of Northern Australia and Papua New Guinea, this miniature marvel reaches a compact adult size of just 1 to 1.2 inches (2.5 to 3 cm). It is universally celebrated for its striking visual contrast: a warm golden-amber chassis dotted with fine dark specks, topped by broad, fan-like fins covered in polka dots and edged in bright white or yellow. Its defining feature is its glowing, light-reflecting electric cyan-blue eyes, which shine like tiny neon bulbs across planted aquariums.

Tank/Plant Profiles & Environmental Requirements

• Care Level: Easy to Moderate (Thrives best in mature, well-established nano planted tanks)

• Growth Rate / Activity: Active; Display-Oriented Top-to-Midwater Swimmers

• Lighting: Low to Moderate (Dappled or floating plant shade makes their metallic eyes and fin colors flash vividly)

• Temperature: 23°C – 28°C (Thrives naturally in Bacolod’s tropical climate)

• Tank Placement: Mid-to-Top Water Column Swimmers

• Minimum Tank Size: 5–10 Gallons (Must be kept in a group of 6 to 10+ minimum with a balanced male-to-female ratio for courtship displays)

Local Care Tips for Bacolod Aquarists

Bacolod Tap Water Conditioning & Tannin Magic: Pseudomugil gertrudae naturally hails from soft, tannin-stained habitats, but tank-bred specimens adapt smoothly to Bacolod’s typical neutral to slightly hard tap water (pH 6.8–7.6) when conditioned properly. To unlock their brightest fin colors and support overall health, we highly recommend aging your water with local Talisay (Indian Almond) leaves or natural driftwood. The gentle humic acids and soft golden tannins released will protect their delicate slime coats, reduce stress, and recreate their cozy native home.

Aquascaping & High-Contrast Plant Protection: To highlight the intricate spotted fins and glowing cyan eyes of Gertrude’s Rainbowfish, set up your aquarium with dark backgrounds and dark substrates. They look magnificent school-gliding over bright green carpets of Monte Carlo or Dwarf Hairgrass. Frame the background and midground with dense stem plants or shade-loving epiphytes like Anubias Nano, Java Ferns, or Bucephalandra bound to local driftwood. Always leave the rhizomes of these epiphytes completely exposed above the aqua-soil to keep them from rotting! Add floating plants like Amazon Frogbit to dapple the light.

Micro-Dietary Care & Ultra-Peaceful Community Etiquette: Due to their small upturned mouths, Gertrude’s Blue-Eyes require small, micro-sized foods. Offer finely crushed high-grade flakes, spirulina powder, micro-pellets, and regular treats of live or frozen baby brine shrimp, daphnia, or rotifers. Keeping a higher ratio of females to males triggers harmless, mesmerizing fin-flaring “wing-flapping” dance battles between rival males. They are among the most peaceful fish in the hobby and are 100% safe to house alongside adult Neocaridina/Caridina dwarf shrimp, Pygmy Corydoras, and micro-rasboras. Always maintain a secure, tight-fitting lid or mesh cover on your tank, as energetic courtship flutters near the surface can occasionally cause accidental leaps.