Pseudomugil gertrudae
A jewel of a nano fish, tangerine fins flecked with neon-blue eyes that glow in side light. Males fin-flick in slow-motion display, like miniature rainbowfish. Short-lived (often only 18 months) so keep continuous fry-friendly growth in floating moss to replace the colony naturally.
Spotted Blue-eye (Pseudomugil gertrudae) reaches 3–4 cm as an adult and needs a minimum tank of 40 L. Native to Northern Australia, New Guinea, Aru Islands, it lives in the mid to top water column with a peaceful temperament. Aim for 22–28 °C, pH 5.0–7.5, and 1–12 dGH hardness. Lifespan is 1–2 years with good care. Keep spotted blue-eye in groups of 6+, loose group schoolers need numbers to display natural behaviour. Diet: micropredator, Tiny live and frozen foods preferred, daphnia, microworms, baby brine shrimp, finely crushed flake. Plant-safe: Yes. Shrimp-safe: Yes (with adults).
Care at a glance
A jewel of a nano fish, tangerine fins flecked with neon-blue eyes that glow in side light. Males fin-flick in slow-motion display, like miniature rainbowfish. Short-lived (often only 18 months) so keep continuous fry-friendly growth in floating moss to replace the colony naturally.
By Mike ElmiraUpdated 1 min read
Part of our complete guide to aquarium fish for the planted tank.
The parameters that decide whether spotted blue-eye fits in your tank.
Mid to Top
No
Small group of 6+
Pseudomugilidae
Micropredator
Tiny live and frozen foods preferred, daphnia, microworms, baby brine shrimp, finely crushed flake.
1–2 yrs
Medium
Northern Australia, New Guinea, Aru Islands
Northern Australia, New Guinea, Aru Islands
Tank-mate safety and the species this one is documented to thrive (or fail) alongside.
Direct answers to the questions search engines and AI assistants surface most often about this species.
Spotted Blue-eye (Pseudomugil gertrudae) needs a minimum tank of 40 L. They live in the mid to top water column and should be kept in groups of 6+, so a longer footprint matters more than depth.
Target 22–28 °C, pH 5.0–7.5, and 1–12 dGH hardness. Acclimate slowly when moving them between water sources.
Shrimp safety: Yes (with adults). Plant safety: Yes.
Spotted Blue-eye are micropredator. Tiny live and frozen foods preferred, daphnia, microworms, baby brine shrimp, finely crushed flake.
On Fin & Stem's 1–5 difficulty scale this species rates 3/5. Intermediate, stable parameters and a mature tank matter. Breeding difficulty: medium.
Typical lifespan in a well-maintained tank is 1–2 years.
A planted tank is a system. Pair this fish with one entry from each other pillar to plan the whole scape.
