Maximum size : 5.5 cm

Forktail Blue Eye Rainbowfish - Pseudomugil furcatus : Complete Fish Profile & Care Guide

Table of contents


The Forktail Blue-eye Rainbowfish (Pseudomugil furcatus) is a small, hardy, adaptable, and peaceful species that is easy to care for, making them an ideal choice for both beginner and advanced aquarists. Their stunning and striking colouration adds a captivating touch to any aquarium. These Rainbowfish are a fantastic addition to nano or planted aquariums.

Forktail Blue-eye Rainbowfish can be housed with other small, peaceful species or showcased as the main attraction in a beautifully aquascaped tank. Appropriate tank companions should exhibit a diminutive and tranquil nature, along with a preference for congruent water parameters. Exemplary candidates encompass certain smaller Rainbowfish species and various diminutive Cyprinids. Moreover, small benthic Gobies and Cory Catfish are judicious selections, aligning harmoniously with Forktail Rainbowfish, which predominantly inhabit the middle to upper strata of the aquarium. 

It is recommended to uphold the presence of Forktail Rainbowfish in congregations comprising at least 10 individuals, ideally maintaining a ratio of one or two females for every male. This practice not only contributes to reducing their anxiety but also yields a more authentic and visually appealing exhibition.

The optimal aquarium setup for these Rainbowfish includes dense vegetation featuring floating aquatic plants, as well as driftwood roots and branches to help diffuse light. A dark background and substrate further enhance the fish's vibrant colours. Filtration must be effective, ensuring water quality while also maintaining well-oxygenated conditions; however, it's imperative to strike a balance and avoid excessive water flow.

The Forktail Blue-eye Rainbowfish boasts a grey to green body colouration with bright yellow edges on all fins, complemented by black margins on the rear dorsal, anal, and caudal fins. During spawning, males also display a striking red hue on their chest area. While the vibrant colours are not present in juveniles, they intensify as the fish mature.

Forktail Blue Eye Rainbowfish Photos

Sexual Dimorphism

Distinguishing between male and female Forktail Blue-eye Rainbowfish is relatively straightforward. Males exhibit more intricate patterns and their unpaired fins become noticeably elongated as they mature. Conversely, females display duller coloration and less complex patterning compared to their male counterparts.

Featured Male
Featured Female
Female Male

Quick Facts

Scientific NamePseudomugil furcatus
Year Described1955
Other NamesForktailed Rainbowfish, Blue Eye Forktail Rainbowfish
OriginsPapua New Guinea Papua New Guinea
Max Size5.5 cm
Aquarium LevelMiddle
Best kept asGroups 5+
Diet & FeedingOmnivore
ReproductionEgg Depositor
LifespanUp to 5 Years

Water Parameters

Water TypeFreshwater
pH 6.0 - 8.0
GH 8 - 18
KH 5 - 12
Ideal Temperature
75 - 79
23 - 26

Natural Habitat

The Forktail Blue-eye Rainbowfish is a fascinating species that call Collingwood Bay and Dyke Ackland Bay in Papua New Guinea their home. These stunning fish are exclusively found in the region and can be observed swimming gracefully in clear, lowland streams and tranquil pools that are enveloped by lush greenery.

These remarkable creatures thrive in slow-moving water bodies that are surrounded by dense vegetation, creating a picturesque and serene environment that is perfect for observing their beauty. The sandy and rocky substrate in their habitats provides an ideal foundation for their playful and energetic behaviour.


Forktail Blue-eye Rainbowfish, known for their egg-scattering spawning behaviour, do not provide parental care and may consume their eggs and offspring if given the opportunity. Increased temperatures within their preferred range enhance the likelihood of spawning. Over several days, females lay a few eggs daily, attaching them to aquatic plants or spawning mops. Males often mate with multiple females in a single day, with spawning generally continuing throughout warmer periods.

Two main breeding methods exist for these fish. The first method involves isolating a small group of 6 to 8 individuals, or one male with two or three females, in a breeding tank fitted with an air-powered sponge filter and spawning materials like nylon mops or java moss. Inspect the media daily for eggs and, if discovered, move them to a separate tank for hatching and incubation.

An alternative approach is to house a colony of adults in a more expansive, fully furnished setup. A densely planted environment may enable some fry to survive. Since fry tends to remain near the water's surface, it is advised to position aquatic plants high in the water column. Floating plants with extended roots can also prove beneficial. Though the second method may be less efficient, it is simpler and more dependable.

A well-established planted aquarium ensures relatively stable water conditions, and the emerging microfauna can act as an initial food source for fry. Eggs usually hatch within 14 to 21 days, subject to temperature. Fry can instantly consume premium dried powder, baby brine shrimp, and microworms.

Provide small, twice-daily meals for optimal growth. To minimize mortality rates, conduct small water changes every 2 to 3 days and refrain from allowing uneaten food to accumulate in the raising tank. Preserving water quality is essential for successfully raising Forktail Blue-eye Rainbowfish fry.

Diet & feeding

Forktail Blue-eye Rainbowfish thrive on a diverse diet, and these adaptable fish readily accept a wide range of food types. A high-quality tropical granule or flake food should serve as the staple of their diet. In addition to this, they will consume live, freeze-dried, or frozen meaty foods, such as Daphnia, blackworms, and brine shrimp. Forktail Blue-eye Rainbowfish also appreciate blanched vegetables as part of their balanced diet.


Forktail Blue Eye Rainbowfish (Pseudomugil furcatus) Freshwater Aquarium Fish Profile & Care Guide Thumbnail

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