Max Size: up to 7 cm

Pacific Blue Eye Rainbowfish (Pseudomugil signifer)

The Pacific Blue Eye Rainbowfish has a peaceful disposition, are active, relatively hardy, have beautiful colouration and are one of the most versatile and variable species of its family. This Rainbowfish makes an excellent member of the nano or well-planted aquarium.

Ideal tankmates for this Rainbowfish could include other Rainbowfish as well as other peaceful fish species of similar size, disposition, and water requirements such as Cyprinids, Gobies and smaller Barbs. Dwarf Shrimp can also make good tankmates; however, small Shrimplets may fall prey to these fish.

Pacific Blue Eye Rainbowfish are a shoaling species; therefore, it would be better to keep them in a group of at least 8 to 10 individuals, preferably more. Maintaining these fish in such numbers will not only make them less nervous but will also result in a far more effective, natural-looking display.

Males will also display some fascinating behaviour and show off their best colours as they compete for female attention.

You will need to keep these Rainbowfish in a spacious aquarium as the males are very intolerant of each other when they are in spawning condition. Sometimes, subdominant individuals may kill one another if the aquarium is too small. Therefore, keeping them alongside other aquatic species is usually recommended to disperse aggression.

Pacific Blue Eye Rainbowfish have elongated partly transparent bodies and pale yellow or olive with a silver operculum and stomach. Their scales are relatively large and are longer vertically than horizontally. Their eyes are large and have a blue iris. These Rainbowfish have two dorsal fins; the first is typically in line with or just posterior to the longest pectoral-fin ray. In addition, they possess a forked tail fin with rounded tips, and the bottom and top edges of the tail fin are bordered with white.

The males usually have extended filaments on their dorsal, pelvic and anal fins. In addition, there are black markings on the base of the anterior rays of the anal and rear dorsal fins, the front is sometimes white, and the back edge is greyish. The male's fins may turn orange during the breeding season.

Quick Facts
Scientific NamePseudomugil signifer
Other NamesNone
Aquarium LevelMiddle - Top
Best kept asGroups 8+
Lifespan2 - 3 years
Water Parameters
Water TypeFreshwater
Temperature75 - 79 ℉ (23.9 - 26.1 ℃)
PH6.5 - 7.5
GH5 - 15
TDS90 - 268
Pacific Blue Eye Rainbowfish
Pacific Blue Eye Rainbowfish
Pacific Blue Eye Rainbowfish

Natural Habitat of the Pacific Blue Eye Rainbowfish

Pacific Blue Eye Rainbowfish has been collected from Sydney, New South Wales state, eastern Australia. Their range stretches along most of the country's eastern coastline, from Merimbula Lake in southern New South Wales, close to the border with Victoria state, to southwards from the Cape York Peninsula in northern Queensland state.

These Rainbowfish are generally found close to the sea; however, their habitats are incredibly variable, and this species has been recorded in fully marine conditions and pure freshwater environments.

Pacific Blue Eye Rainbowfish usually inhabits swamps, coastal mangrove creeks, and salt marshes. Freshwater habitats typically include lowland swamps or forest streams with clear water, although some inhabit acidic, tannin-stained, black waters. These fish are also abundant in the artificial canals typical of residential zones in the Gold Coast in southern Queensland.

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)
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What to feed the Pacific Blue Eye Rainbowfish

Pacific Blue Eye Rainbowfish feed primarily on suspended or floating phytoplankton, zooplankton and invertebrates in nature. Therefore, in the aquarium, you should offer them food of a suitable size.

Ideally, much of this species diet should include live and frozen foods such as cyclops, brine shrimp, bloodworm, microworm and daphnia, although they will also readily accept small dried foods such as crushed flake and micropellets.

How to Sex the Pacific Blue Eye Rainbowfish

It is quite easy to differentiate between male and female Pacific Blue Eye Rainbowfish. Mature males are usually more patterned, are more brightly coloured and display longer finnage than females. The male is also a little larger and possesses black markings on their anal and dorsal fins.

How to Breed the Pacific Blue Eye Rainbowfish

Pacific Blue Eye Rainbowfish are egg layers that present no parental care and will often consume their eggs and fry if given an opportunity. However, in a well-decorated aquarium, some may survive.

Spawning is more likely to occur in slightly higher temperatures. Females deposit a few eggs daily for several days, attaching them to aquatic vegetation or other substrates by sticky threads. Individual males will also mate with multiple females during a single day, and spawning usually continues throughout daytime hours during warmer weather.

In nature, these Rainbowfish display a seasonal reproductive cycle corresponding with the onset of the wet season, around October to December, when aquatic vegetation and food are at their most abundant.

Spawning usually occurs during daylight hours, with a burst of activity late morning to early afternoon. Breeding can occur throughout the year in the aquarium if the temperature is kept at the same values.

You can use two methods to spawn these fish; the first involves isolating a small group of 6 to 8 individuals or a single male and two or three females into a separate breeding tank with an air-powered sponge filter and a spawning medium such as nylon mops or aquatic moss. You will need to check this daily, and if you find any eggs, you will need to move them into a separate rearing tank for incubation and hatching.

Another method you may use is maintaining a colony of adults in a more extensive, fully-decorated set-up that should allow some fry to survive if well-planted. However, the fry initially spends most of its time close to the water's surface. Therefore, it is advised that you attach aquatic mosses to decor high up in the aquarium or use floating plants with long roots, as this will produce the most favourable results.

The second approach is usually less productive but more straightforward and reliable as established and planted aquariums facilitate relatively stable water conditions. In addition, the resident microfauna can create a valuable early food source for the fish fry.

The incubation period for these Rainbowfish is usually between 10 and 21 days depending on temperature, and the fry can accept baby brine shrimp, microworm, and similarly-sized foods immediately. You can also raise them on good quality, powdered dry products. It would be best if you offered your fry small meals at least twice a day.

It would be beneficial to remember that aged water can result in high mortality, so performing regular, small water changes are essential. Any uneaten food needs to be removed and should not be allowed to accumulate in the rearing tank.

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Date Added: 05/08/2021 15:22:04 - Updated: 05/08/2021 15:43:27