Neon Rainbowfish (Melanotaenia praecox)

Common Name:

Neon Rainbowfish.

Other Names:

Dwarf Rainbowfish, Praecox Rainbowfish, Dwarf Neon Rainbowfish.

Scientific Name:

Melanotaenia praecox.

Family:

Melanotaeniidae.

Distribution:

Mamberamo River of Irian Jaya, Indonesia.

Size:

2 - 3 inches.

Diet:

They need smaller foods than most fishes as they have a throat with a comparatively small diameter. They are omnivorous, so they'll take live foods and standard foods for tropical community fishes.

Water Temperature:

75 to 82 degrees Fahrenheit (24-28 Celsius).

Water Chemistry:

Soft water, though acclimation to moderate hardness is probably possible.

pH:

6.5-7.5.

Life Span:

3-5 years.

Description:

These have an extremely deep laterally compressed body. Like all rainbow fishes, these fish have two dorsal fins but, like most of the popular rainbows, the split dorsal is barely noticeable as one of these fins is very tiny. The Neon Rainbow is a metallic color throughout. Its fins are almost uniformly red (with the exception of the outer edge of the caudal fin, which is green). The same green covers most of the bottom of the fish while the upper lateral surfaces are usually blue (with a greenish stripe perhaps mixed in). These colours may be perceived differently as the iridescent reflections may change under different types of light.

Behaviour:

Small, active, and peaceful, they do best in groups of six or more (one male to two females ratio, if possible). They are not for the tank with fishes stressed by activity or for the tank, which has highly active denizens. Any other tank with soft, slightly acidic water, lots of swimming space and lots of plants is a great home for them.

Minimum Recommended Tank Size:

20 gallons for a small shoal.

Natural Conditions:

It seems as though they live in slightly acidic tributary-type waters of the Mamberamo River, which are well planted at their edges.

Sexing:

Females' fins are less red than males'; they often have yellow to yellowish-orange fins. They are less colourful than the males as well.

Breeding:

They breed themselves, i.e., many aquarists just see eggs in the tank after having done nothing special to induce breeding. They don't stop spawning for a long time after they start!

Males start the spawning process by displaying to the females and the spawning almost always takes place in the morning (though you can likely affect the time of spawning by changing the times at which the fish room is light).

The fry mature more quickly than those of other Rainbows, but they can still take months to develop. Microencapsulated fry foods are good starter foods, as are microworms. Anything much larger can and may cause serious damage to a fish whose mouth is large but throat is not.

Miscellaneous:

Be warned: their mouths are large but their throats are narrow. Don't feed overly large foods!

Likewise, 10 gallons is often listed as a minimum tank size, but that fails to take into consideration the fact that these are schooling fish that live to eat.

Photo Credit:

Photo 1 supplied courtesy and ^©Off-ice.
Photo 2 supplied courtesy and ^©Bluelagoon.