Max Size: 6cm

Dwarf Neon Rainbowfish (Melanotaenia praecox)

The Dwarf Neon Rainbowfish is a small, peaceful, intelligent, beautiful and above all, spirited fish. If kept healthy and happy, these fish will always be active and enjoyable, making them a great addition to any community tank.

Dwarf Rainbowfish do not need a lot of special care, but they are not recommended for new tanks or beginners as they cannot deal with stress very well.

The Dwarf Rainbowfish can be somewhat skittish so keeping them in a group of 6 or more is recommended plus the males will be inspired to show off their best colours in the company of their species.

These fish are all excellent jumpers so tightly cover the tank.

They have an elongated body, big eyes, and the body colour is greyish-pink; however, the scales will light up and look bright blue and iridescent by reflecting light hitting them from the front. The range of blue tones is surprising going from lavender to a teal depending on the light they also have brightly coloured twin dorsal fins.

Dwarf Neon Rainbowfish (Melanotaenia praecox) Video

Dwarf Neon Rainbowfish (Melanotaenia praecox) Freshwater Aquarium Fish Species Profile & Care Guide


Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Drawf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Dwarf Neon Rainbowfish
Quick Facts
Scientific NameMelanotaenia praecox
Other NamesNeon Rainbowfish, Dwarf Rainbowfish, Peacock Rainbowfish, Praecox Rainbowfish, Diamond Rainbowfish,
OriginsIndonesia, Papua New Guinea
Aquarium LevelMiddle
DifficultyBeginner - Intermediate
Best kept asGroups 6+
Lifespan3 - 5 years
Water Parameters
Water TypeFreshwater
PH6.5 - 7.5
GH5 - 15
72 - 79℉
22.2 - 26.1℃


In the home aquarium, the Dwarf Neon 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

3 interesting tank mate ideas for the Dwarf Neon Rainbowfish could include:

Dwarf Gourami(Trichogaster lalius)
Glowlight Danio(Celestichthys choprae)
Ivantsoffs Blue Eye Rainbowfish(Pseudomugil ivantsoffi)

Sexual Dimorphism

Sexing Dwarf Neon Rainbowfish is straightforward and effortless.

Males are larger and display brighter colouration than females. They also exhibit a much deeper body than females as they grow. The male's fins will be edged in red whereas the female's edges are an orangy-yellow. The females are also more silver in colour.


Breeding the Dwarf Neon 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)
Forktail Blue Eye Rainbowfish(Pseudomugil furcatus)
Honey Blue Eye Rainbowfish(Pseudomugil Mellis)
Ivantsoffs Blue Eye Rainbowfish(Pseudomugil ivantsoffi)
View all Rainbowfish
Date Added: 04/09/2020 - Updated: 12/08/2022 12:28:09