A stunning, highly active nano fish native to Australia and New Guinea. Known for their striking blue eyes and the males' spectacular, heavily spotted fins which they flare during dominance displays. They are peaceful but require being kept in shoals to thrive and exhibit natural behaviors.
At a Glance
Tank Requirements
Water Parameters
Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Male
Males boast dramatic, elongated dorsal and anal fins covered in distinct spots. They spend much of their time displaying to rival males and courting females. Best kept in a ratio of 1 male to 2+ females.
Differs in 3 traits from base species
Also known as: Male Spotted Blue-eye, Show Male
Female
Females are slightly smaller, plumper, and lack the elaborate finnage and intense spotting of the males. They are essential for a healthy group dynamic to disperse male courting attention.
Differs in 2 traits from base species
Also known as: Female
Gertrude's Spotted Blue-eye Care Guide Summary
The Gertrude's Spotted Blue-eye, scientifically known as Pseudomugil gertrudae, belongs to the Rainbowfish family group. Adults reach a maximum size of approximately 3.8 cm and have a fusiform body shape with a moderate growth rate. Classified as peaceful, this species primarily occupies the surface and mid-level zones of the aquarium and produces a low level of biological waste.
To thrive, the Gertrude's Spotted Blue-eye requires a freshwater only aquarium with a minimum volume of 38 litres and a tank length of at least 45 cm. Water temperature should be maintained between 21°C and 28°C, with a pH range of 6–7.5 and a general hardness of 5–15 dGH. A moderate water flow is preferred.
Due to its specialist needs, the Gertrude's Spotted Blue-eye is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Male and Female. Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Gertrude's Spotted Blue-eye Habitat Setup
When setting up an aquarium for the Gertrude's Spotted Blue-eye, a moderate water flow best suits their natural preferences. Because this species occupies the surface and mid-level zones, the aquarium layout should prioritise adequate surface area with floating cover to make them feel secure near the waterline and open swimming space in the centre of the tank for free movement. Useful additions include leaf litter or blackwater tannins to replicate their natural soft-water habitat, dense planting to provide cover, break sightlines, and reduce stress, and floating plants to diffuse overhead light and create shaded areas. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Gertrude's Spotted Blue-eye Compatibility Notes
Classified as peaceful, the Gertrude's Spotted Blue-eye is a schooling species that feels most secure in a sizeable group, where natural shoaling behaviour reduces stress and brings out their best colours. When choosing tankmates, their energetic swimming style may stress more sedentary or timid species. Selecting tankmates that favour different water layers from the surface and mid-level zones can help reduce competition and territorial overlap.
Frequently Asked Questions About Gertrude's Spotted Blue-eye
How big does Gertrude's Spotted Blue-eye get?+
What tank size does Gertrude's Spotted Blue-eye need?+
What water parameters does Gertrude's Spotted Blue-eye need?+
Is Gertrude's Spotted Blue-eye peaceful or aggressive?+
How many Gertrude's Spotted Blue-eye should be kept together?+
Does Gertrude's Spotted Blue-eye have any special tank requirements?+
Does Gertrude's Spotted Blue-eye need a lid on the tank?+
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