Dwarf Neon Rainbowfish

Geographical Origin:

They come from a dense network of rainforest streams and swamps associated with the vast Mamberamo river basin in northern West Papua. The waters in these regions are often rich in marginal vegetation and fallen branches.

Sexual Dimorphism and Coloration:

Both sexes possess the unmistakable reflective neon blue brilliance over their entire body. The difference lies in the fins (dorsal, anal, and caudal) and in the profile. In dominant males, the fins are bordered with an intense **bright scarlet red** and they have a more arched and deeper back; in females, the margins of the fins are a delicate pale yellow/orange and the body remains thinner and more tapered.

Tank Setup:

Being the "pocket" version of the Rainbowfish, they do not need 2-meter tanks. A group of 8-10 individuals will live happily in a planted aquarium of 80-100 cm (30-40 inches, 100-120 liters). Compared to their larger cousins, they love the security provided by dense vegetation. Forests of *Limnophila*, *Vallisneria*, or moss-covered wood will help them feel at ease. A cover of floating plants (like *Salvinia* or *Pistia*) will lower the brightness, making the iridescent neon color of their flanks explode.

Diet:

They have proportionally narrow throats even compared to their small size. Avoid hard pellets or large flakes that can cause choking or internal damage. Feed finely crushed food. They are enthusiastic predators of small insects: wingless fruit flies (Drosophila), live daphnia, and brine shrimp nauplii are their food of choice and will keep the fish healthy and ready to breed.

Water Quality:

They are slightly more chemically flexible than *M. boesemani*, preferring neutral or slightly acidic waters (pH 6.5 - 7.5), which makes them excellent companions for many South American species (Tetras, Corydoras). However, they inherit the family's genetic weakness for poor water quality: if the aquarium is overcrowded or filtration is inadequate, they are prone to developing fatal mycobacteriosis (fish tuberculosis).