Max Size: 2.5cm

Spotted Blue Eye Rainbowfish (Pseudomugil gertrudae)

The Spotted Blue Eye Rainbowfish is a small good looking, peaceful and timid species and must be kept in groups or they will become skittish and feel intimidated. They are not ideal for the community tank as they may be outcompeted for food and are therefore bust kept alone or alongside other fishes of comparable size, requirements and disposition.

The Spotted Blue Eye Rainbowfish have a compressed and elongated body that is a semi-transparent blueish-silver colour, occasionally having an overall gleam of golden-yellow. Their swim bladder is visible, and they have two dorsal fins, very close together. The first fin is much smaller than the second.

The tips of the pectoral fins are usually bright yellow, orange or orangey-red, and the other fins are often bordered with white. The anal, dorsal, and tail fins can be transparent to white, silvery-grey or yellow with oblong or rounded dark spots spread all over.

Several rows of body scales are bordered in black, displaying a charming latticework pattern over the body. All scales except those of the mid-ventral and mid-dorsal rows have a spot ranging in size and intensity forming about six rows of irregular lines, except for the mid-lateral stripe, which seems to be continuous from just below and in line with the start of the first dorsal fin to the caudal peduncle.

There is considerable variation between these species in colouration and body size, as well as fin size and shape.

Tank Mates for the Spotted Blue Eye Rainbowfish

1 ideal tank mate ideas for the Spotted Blue Eye Rainbowfish include:

Staeck Endler(Poecilia wingei)
Quick Facts
Scientific NamePseudomugil gertrudae
Other NamesSpotted blue-eye
OriginsAustralia, Papua New Guinea
Aquarium LevelMiddle
DifficultyBeginner - Intermediate
Best kept asGroups 5+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH4.5 - 7.5
GH5 - 12
TDS90 - 215
73 - 86℉
22.8 - 30℃

Photos of the Spotted Blue Eye Rainbowfish

Spotted blue eye rainbowfish
Spotted blue eye rainbowfish
Spotted blue eye rainbowfish
Spotted blue eye rainbowfish
Pseudomugil gertrudae
Spotted Blue-Eye Rainbowfish

Natural Habitat

Spotted Blue Eye Rainbowfish can be found in many rivers draining into the Gulf of Carpentaria and the Timor Sea extending eastwards from the city of Darwin through Arnhem Land, Carpentaria, Kakadu National Park, as far as the Cape York in Peninsula.

It is also known from the islands of Melville, Bathurst and Groot Eylandt, plus some smaller islands in the Torres Strait in Papua New Guinea and northern Australia.

They inhabit shallow, small areas of slow-moving almost still heavily-vegetated streams, billabongs, creeks, lakes and swamps, and is regularly found among macrophytes, submerged woody structures such as tree roots or fallen branches and leaf litter.

At some locations, the water may be transparent where others may be stained dark brown with tannins and has very low pH and dissolved nutrients.

What to feed the Spotted Blue Eye Rainbowfish

This fish isn't particularly fussy and will accept most food you give them. Ensure that they receive a balanced diet compromising of high-quality flake food as well as frozen or live food like brine shrimp and bloodworm, which they prefer to dry food.

Remember though these fish only have little mouths, so make sure any food particles are suitable in size so they can be swallowed easily.

How to sex the Spotted Blue Eye Rainbowfish

It is relatively easy to determine the males from the females. Females commonly have a more profound body than the males whilst the adult males have larger dorsal, pelvic and anal fins, with extended filaments on the first dorsal and pelvic fins. The males also present more intense colour and spots on the fins and body.

How to breed the Spotted Blue Eye Rainbowfish

The Spotted Blue Eye is an egg-scatterer presenting no paternal care and will consume its eggs and fry given a chance.

Spawning is more likely to occur with warmer temperatures, with females capable of attaching a few eggs daily over several days, on aquatic plants or other substrates by sticky threads.

If in the same tank, an individual male can also mate with multiple females in a single day, and spawning usually continues throughout daytime hours throughout warmer periods.

In their natural surroundings, they display seasonal reproductive cycles corresponding with the onset of the rainy season, around October-December, when the food and vegetation are at their most abundant.

Spawning occurs during daytime hours with a height of activity in the late morning to the early afternoon when the water temperature is relatively warm. In the aquarium, breeding can happen throughout the year if the aquarium temperature is reasonably high.

There are two methods you can try to breed these fish. The first involves separating a small group containing a single male and two or three females into a breeding tank with plenty of plants or a spawning mop and an air-powered sponge filter. Make sure you check these for eggs several times a day, taking care to remove any if spotted into a grow-out tank for incubation and hatching.

The second is to have a group of adults in a more extensive, fully-decorated set-up which if heavily planted should allow some fry to survive as they can hide in the plants or the roots of floating plants. This method is the more comfortable option but not ideal if you want a high quantity of fry.

The eggs will hatch roughly ten days after being laid depending on temperature. The fry will need microscopic food such as unicellular organisms or good quality powdered food for around five days. after this they will be able to accept things like freshly hatched brine shrimp or microworms this should be given twice a day.

Ageing water and uneaten food accumulating can lead to high mortality rates, so small water changes regularly are essential in the rearing tank.

Other Rainbowfish of interest

Banded Rainbowfish(Melanotaenia trifasciata)
Boesemans Rainbowfish(Melanotaenia Boesemani)
Celebes Rainbowfish(Marosatherina ladigesi)
Dwarf Neon Rainbowfish(Melanotaenia praecox)
Forktail Blue Eye Rainbowfish(Pseudomugil furcatus)
Honey Blue Eye Rainbowfish(Pseudomugil Mellis)
View all Rainbowfish
Date Added: 18/09/2020 - Updated: 02/02/2022 16:35:55