Gertrude's Blue Eye — a Pseudomugilidae from 大洋洲, peaceful but energetic; needs open swimming room. Reaches 4–8 cm; shoaling; 8+ in a long tank unlocks full colour. 20–26 °C.
Care parameters
Water temperature
20–26 °C
pH
6.5–7.5
GH hardness
5–15 dGH
Adult length
4–8 cm
Minimum tank
77 L
Water layer
Middle of the water column
Difficulty
Moderate
Temperament
Peaceful but energetic; needs open swimming room
Origin
大洋洲
Species overview
Pseudomugil gertrudae is a Pseudomugilidae from 大洋洲. Its iridescence is honest signalling: colour and condition track water quality and age together. It swims in mid-water. Adults reach 4–8 cm. Shoaling; 8+ in a long tank unlocks full colour. Provide swimming length, clean hard water and a big school; patience does the rest. Maintain 20–26 °C at pH 6.5–7.5. Best suited to a keeper who can match its natural water.
Native biotope
Habitat
Warm freshwater streams and lakes
Flow
Still to gentle current
Dissolved O₂
Moderate oxygen levels
Aquascape & hardware
Substrate
Fine sand and gravel
Hardscape
Driftwood and smooth stones
Plants
Hardy common aquarium plants
Temperament, diet & tankmates
Schooling
Shoaling; 8+ in a long tank unlocks full colour
Diet
Eager eater; varied diet maintains iridescence
Recommended tankmates
Robust peaceful cyprinids — Add motion without menace