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Maximum size : 6 cm

Dwarf Neon Rainbowfish - Melanotaenia praecox : Complete Fish Profile & Care Guide

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The Dwarf Rainbowfish, (Melanotaenia praecox) while not particularly demanding, are not ideal for novice aquarists or newly established tanks as they are sensitive to stress. However, these charming fish are sure to make a delightful addition to any experienced hobbyist's aquarium. To fully showcase their vibrant colors and active behavior, a group of at least six should be kept together, as the males are inspired to display their best colors in the presence of their own kind. These peaceable creatures are compatible with a variety of species and will not damage aquatic plants, making them an excellent candidate for a community aquarium. Care should be taken not to house them with larger and boisterous fish to avoid stressing the Dwarf Rainbowfish. When creating an ideal environment for these fish, a 3ft or larger tank is recommended, with plenty of aquascaped plants and bogwood to create a multitude of hiding places for the fish to explore. The central portion of the aquarium should be left open for swimming space. The use of floating plants can help to diffuse bright lighting and provide a natural look to the setup. As these fish have a propensity to jump, it is essential to have a tightly-covered tank. The Dwarf Rainbowfish possess an elongated body, striking big eyes, and a greyish-pink body color that appears iridescent with the reflection of light, creating a stunning display of blue tones ranging from lavender to teal. Their twin dorsal fins are also brightly colored and add to their overall beauty. With their captivating appearance and active personalities, the Dwarf Rainbowfish are a delightful addition to any aquarium.

Dwarf Neon Rainbowfish Photos

Sexual Dimorphism

Determining the sex of the Dwarf Neon Rainbowfish is a straightforward and uncomplicated task. Males can be easily distinguished from their female counterparts based on their larger size and more vivid coloration, as well as a significantly deeper body as they mature. Males exhibit a striking red hue along the edges of their fins, while the female's fins display a contrasting orangy-yellow edge. Furthermore, females tend to have a silver appearance compared to the males' vibrant colors.

Quick Facts

Scientific NameMelanotaenia praecox
Year Described1922
Other NamesNeon Rainbowfish, Dwarf Rainbowfish, Peacock Rainbowfish, Praecox Rainbowfish, Diamond Rainbowfish,
OriginsPapua New Guinea Indonesia
Max Size6 cm
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

Natural Habitat

Dwarf Rainbowfish are Found in the lush jungle streams of Western New Guinea's Mamberamo region in Southeast Asia, this aquatic wonder is a true sight to behold. These magnificent fish can be spotted in swiftly flowing, clear, soft, and acidic waters just off the main river. You can also find them in the marshes and swamps that surround the area. Their favourite spots to hang out include areas with dense aquatic vegetation, as well as submerged logs and roots. So, if you're ever in the mood for a breathtaking underwater adventure, make sure to keep an eye out for the vibrant and lively Dwarf Rainbowfish!


Breeding the Dwarf Neon Rainbowfish is a relatively straightforward process, but successfully raising the fry requires careful attention and effort. To begin, a separate breeding tank that is heavily planted with fine-leaved plants or Spawning mops should be set up. The temperature of the water should be raised a few degrees above average, and the water should be slightly hard with some alkalinity. A small air-powered filter is advisable to provide adequate flow and oxygenation. Before breeding, it is important to condition the fish with protein-rich frozen or live foods for at least two weeks to stimulate their reproductive cycles. As the breeding season approaches, males will begin to display courtship behaviors, and females will become noticeably plumper. Selecting the healthiest and best-colored fish, they should be transferred to the breeding tank to begin spawning. During spawning, the male will lead the female to a spawning area, where she will lay groups of eggs that the male will fertilize. This process will continue until the female has exhausted all her eggs. It is advisable to remove the eggs from the breeding tank every day and place them into a separate grow-out tank to prevent predation by the parents. After seven to ten days, the eggs will hatch into fry, and they will need to be fed tiny invertebrates for about a week until they are able to eat foods such as brine shrimp or nauplii. With attentive care and optimal conditions, raising healthy and robust fry can be achieved.

Diet & feeding

The Dwarf Neon Rainbowfish exhibit an adaptable palate, and their feeding preferences are not overly selective. For optimal health and wellbeing, it is recommended to incorporate high-quality micropellets, flakes, granules, and green flakes as the primary sources of their diet. Additionally, frequent feedings of frozen or freeze-dried food, such as bloodworm, daphnia, mosquito larvae, brine shrimp, and tubifex, will contribute to the fish's overall health and enhance their vibrant coloration.


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

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