Max Size: 3.5cm

Swamp Blue Eye Rainbowfish (Pseudomugil paludicola)

The Swamp Blue-eye Rainbowfish is a small, hardy, adaptable and peaceful species that is easy to maintain, making them ideal fish for beginner aquarists and the more advanced aquarists. You can house these Rainbowfish in a nano aquarium or a well-planted aquarium alongside other small and peaceful species that appreciate the same environment and water conditions, or you can maintain them in a species-only, high-quality aquascaped aquarium.

Ideal tankmates for the Swamp Blue Eye Rainbowfish could include other Pseudomugil Rainbowfish such as the Red Neon Blue Eye, Spotted Blue Eye and the Popondetta Blue Eye. However, it should be noted Pseudomugil species can hybridise, so if you would like to breed this fish, other smaller Rainbowfish such as the Dwarf Neon Rainbowfish or the Celebes Rainbowfish would make more suitable tank mates.

Other possible tankmates can include other peaceful fish species of similar size, disposition, and water requirements, such as Rasboras, Gobies and smaller Barbs like Pentazona Barbs, Cherry Barbs and Checker Barbs. However, you should avoid maintaining them alongside much larger, more aggressive species.

Swamp 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.

The ideal aquarium setup for Swamp Blue Eye Rainbowfish would contain areas of dense vegetation, including some floating aquatic plants and driftwood roots and branches to help diffuse the light. A strong current in the aquarium is not necessary as these fish come from calmer stretches in the wild.

Swamp Blue Eye Rainbowfish have a semi-translucent body and a silvery abdomen and head, and in some individuals, their bodies shine a blueish silver under a particular light. The fins are also clear on these fishes, but their pelvic fin, anal fin and the edge of the second dorsal fin have a pale yellowish hue.


Swamp Blue-eye Rainbowfish
Swamp Blue-eye Rainbowfish
Quick Facts
Scientific NamePseudomugil paludicola
Year Described1981
Other NamesYellow Fin Blue Eye Rainbowfish
OriginsPapua New Guinea
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 8+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.0 - 8.0
GH5 - 20
79 - 86℉
26.1 - 30℃


In the home aquarium, the Swamp Blue Eye Rainbowfish will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Tank Mates

1 interesting tank mate ideas for the Swamp Blue Eye Rainbowfish could include:

Skunk Corydoras(Corydoras granti)

Sexual Dimorphism

It is relatively straightforward to differentiate between the male and female Swamp Blue Eye Rainbowfish. The males exhibit brighter yellow colouration in the anterior part of the anal fin and on the caudal fin base, as well as on the outer edge of the second dorsal fin. In addition, the males are slightly larger and slimmer than females and have a longer dorsal fin. In contrast, females are smaller, duller and have shorter fins than males.


Breeding the Swamp Blue Eye Rainbowfish is straightforward once these fish are happily established and settled into your aquarium. You will need a mature pair or group of males and females, along with a spawning mop, preferably floating at the top of the aquarium downwards to the substrate.

Despite spawning year-round, Rainbowfish lay many eggs at the beginning of the rainy season. In addition, temperature increases, and live and frozen foods often encourage spawning.

Check your spawning mops daily for any eggs that have been deposited and either remove the eggs from the mop or, better still, remove the entire mop to avoid contamination of the Rainbowfish eggs.

Tip: Have several spawning mops at hand so you can place a fresh spawning mop into the aquarium while you wait for the eggs to hatch on the other mop/s.

Place the spawning mop with eggs still attached into a separate small cycled aquarium with a sponge filter for flow, and add a few drops of Methylene Blue (Methylene Blue helps prevent fungal infections of eggs).

Your rainbowfish Eggs will hatch within 7 to 18 days, depending on the species and the temperature. We recommend 27°C = 80.6°F for the fastest development of fry.

Once the Rainbowfish fry hatch, they absorb their yolk sacs quickly and become free swimming, moving towards the water's surface. Once the fry reaches the water's surface, you can start feeding. We recommend feeding on Micorworm (the most straightforward live food to culture) and decapsulated brine shrimp egg powder several times a day while being careful not to overfeed and pollute the water column.

After a week or two, you can start to add newly hatched brine shrimp, but this isn't necessary to achieve a high success rate in our experience.

Rainbowfish fry grows slowly, so you should expect to wait several months before the fry is large enough to be added to the adult colony.

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: 14/03/2022 12:07:59 - Updated: 12/08/2022 13:22:39