Pacific Blue Eye Rainbowfish - Pseudomugil signifer : Complete Fish Profile & Care Guide
Table of contents
Introduction
The Pacific Blue Eye Rainbowfish (Pseudomugil signifer) is a stunningly colourful and active species that can add a unique touch to any nano, planted or smaller species community aquarium. These peaceful and relatively hardy fish are always up for a sparring match throughout the day, and the males' beautiful colouration and finnage are especially pronounced during these bouts.
When it comes to tankmates, it's important to note that Pseudomugil species can hybridise, so if you aim to maintain their purity, smaller Rainbowfish such as the Celebes Rainbowfish, Ornate Rainbowfish or Dwarf Neon Rainbowfish would be more suitable. Other peaceful species of similar size, disposition and water requirements, such as Peacock Gobies and Neocaridina Shrimp, can also make good tankmates, although small shrimplets may become prey to these fish.
As a shoaling species, Pacific Blue Eye Rainbowfish thrive in groups of at least 8 to 10 individuals, preferably more. These numbers not only make them less nervous but also lead to more natural behaviour and fascinating male competition for female attention. Keeping them in a spacious aquarium is recommended, as males can become intolerant of each other during spawning conditions, and the most dominant ones may harass the subdominants, who can fall victim to stress if the tank is too small.
Pacific Blue Eye Rainbowfish have elongated, partly transparent bodies, and they are usually pale yellow or olive with a silver operculum and stomach. Their relatively large scales are longer vertically than horizontally, and their eyes have a beautiful blue iris. These Rainbowfish have two dorsal fins, with the first typically in line with or just posterior to the longest pectoral-fin ray. Their forked tail fin has rounded tips, and the bottom and top edges of the tail fin are bordered with white. The males typically have extended filaments on their dorsal, pelvic and anal fins and black markings on the base of the anterior rays of the anal and rear dorsal fins. During the breeding season, their fins may turn orange, adding a stunning pop of colour to your aquarium.
Pacific Blue Eye Rainbowfish Photos
Sexual Dimorphism
Mature Pacific Blue Eye Rainbowfish males exhibit a strikingly vibrant hue and possess a longer finnage in comparison to the females, rendering them easily distinguishable. Moreover, the males are slightly larger and feature conspicuous black markings on their anal and dorsal fins.
Quick Facts
| Scientific Name | Pseudomugil signifer |
|---|---|
| Year Described | 1866 |
| Other Names | None |
| Kingdom | Animalia |
| Classification | Actinopterygii |
| Order | Atheriniformes |
| Family | Melanotaeniidae |
| Genus | Pseudomugil |
| Origins | Australia |
| Max Size | 7 cm |
| Temperament | Peaceful |
| Aquarium Level | Middle - Top |
| Difficulty | Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 8+ |
| Diet & Feeding | Omnivore |
| Reproduction | Egg Depositor |
| Average Lifespan | Up to 2 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 6.5 - 7.5 |
| GH | 5 - 15 |
| TDS | 90 - 268 |
| ℉ | 75 - 79 |
|---|---|
| ℃ | 23 - 26 |
Natural Habitat
The Pacific Blue Eye Rainbowfish is an iconic species found along the stunning eastern coastline of Australia, stretching from Merimbula Lake in southern New South Wales to the Embley River in far North Queensland. These vibrant Rainbowfish are known for their resilience, adapting to a wide range of habitats from fully marine conditions to pure freshwater environments. Pacific Blue Eye Rainbowfish can be found in various habitats, including swamps, coastal mangrove creeks, salt marshes, lowland swamps, or forest streams with clear water. These fascinating fish are even found in the artificial canals of the residential zones of the Gold Coast in southern Queensland. Their remarkable ability to adapt to these diverse environments only adds to their charm and appeal for aquarium enthusiasts.
Breeding
Pacific Blue Eye Rainbowfish are oviparous and do not display any parental care. In fact, they may even consume their own eggs and fry if given the chance. However, in a well-structured aquarium, some may survive. Spawning is more likely to occur in slightly higher temperatures, and females deposit a few eggs daily for several days, attaching them to aquatic vegetation or other substrates by sticky threads. Individual males will mate with multiple females during a single day, and spawning usually continues throughout daytime hours during warmer weather. In the wild, these Rainbowfish follow a seasonal reproductive cycle corresponding with the onset of the wet season when food and aquatic vegetation are abundant. Spawning usually occurs during daylight hours, with a burst of activity from late morning to early afternoon.
Breeding Pacific Blue Eye Rainbowfish can be accomplished in two ways. The first involves isolating a small group of 6 to 8 individuals or a single male and two or three females in a separate breeding tank with an air-powered sponge filter and a spawning medium such as nylon mops or aquatic moss. If you find any eggs, they need to be moved into a separate rearing tank for incubation and hatching. Another approach involves maintaining a colony of adults in a larger, fully-decorated setup that allows some fry to survive if well-planted. However, since the fry initially spends most of its time close to the water's surface, attaching aquatic mosses to decor high up in the aquarium or using floating plants with long roots produces the most favourable results.
The second method is usually less productive but more reliable since established and planted aquariums facilitate relatively stable water conditions, and the resident microfauna can create a valuable early food source for the fish fry. The incubation period for these Rainbowfish ranges from 10 to 21 days depending on temperature, and the fry can accept baby brine shrimp, microworm, and similarly-sized foods immediately. Good quality, powdered dry products are also suitable for their diet. Feeding small meals at least twice a day is recommended, and aged water should be avoided as it can result in high mortality. Therefore, performing regular, small water changes are essential, and any uneaten food should be removed and not allowed to accumulate in the rearing tank.
Diet & Feeding
In their natural habitat, Pacific Blue Eye Rainbowfish primarily feed on suspended or floating phytoplankton, zooplankton and invertebrates. Therefore, in a captive setting, providing them with appropriate food that matches their natural diet is crucial. It is recommended to offer them live and frozen foods such as brine shrimp, bloodworm, microworm and daphnia, as these are preferred by the fish. Nonetheless, they are not picky eaters and will readily consume small dried foods such as crushed flake and micropellets.
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