Melanotaenia lacustris – Aquamarine Rainbowfish Complete Overview

Melanotaenia lacustris

The Melanotaenia lacustris (Aquamarine Rainbowfish) occurs exclusively in a highland lake and its drainage in Papua New Guinea. They are known for the following:

  • Fascinating coloring
  • Peaceful company fish
  • Suitable for beginners
  • Breedable

The males of this species are easy to recognize by the blue color of the upper half of the body.

The aquamarine rainbow fish is easy to care for if you offer it a medium-sized aquarium with space to swim and relatively hard, slightly alkaline water. With varied feeding and morning sun in the aquarium, the fish are ready to breed all year round.

Melanotaenia lacustris is known in the aquarium hobby not only as aquamarine rainbow fish but also as blue rainbowfish or Kutubu rainbowfish.

Melanotaenia lacustris (Aquamarine Rainbowfish): Quick Facts

Scientific name:Melanotaenia lacustris
Common name:Blue rainbowfish, aquamarine rainbowfish, Kutubu rainbowfish, turquoise rainbowfish, Lake Kutubu Rainbowfish
Difficulty level:for beginners
Origin / Distribution:Papua New Guinea, Lake Kutubu
Coloring:high back with intense blue tones in the upper back area and in the fins, pointed, terminal mouth, large eyes
Age expectation:6-8 years
Water parameters:GH 2-20, KH 10-15, pH 8.5-9.0, temperature 20-26 ° C
Aquarium size:from 100 l
Feeding:Omnivores, live and frozen food, but also dry food
Behavior:very peaceful
Group size:at least 6 fish

Melanotaenia lacustris (Aquamarine Rainbowfish): Distribution and habitat

The aquamarine rainbowfish, also called the blue rainbow fish or Kutubu rainbow fish, occurs in the 70m deep Lake Kutubu and in its lake outlet, the Soro River. This lake is located in the southern highlands of Papua New Guinea.

These rainbowfish live just below the water surface at water temperatures between 21 and 25 ° C and pH values ​​between 8.5 and 9.0.

Melanotaenia lacustris (Aquamarine Rainbowfish): Features, Shape and Color

The extent and intensity of the blue coloration in the aquamarine rainbow fish depends on various factors such as the food available and the water parameters.

The color spectrum of the males ranges from pure cobalt blue, steel construction, aquamarine to turquoise, with the upper half of the body being more intensely colored than the lower half.

The females are paler in color and less high back than the males.

Melanotaenia lacustris
Melanotaenia lacustris

Melanotaenia lacustris (Aquamarine Rainbowfish): In the Aquarium

The aquamarine rainbowfish is an easy-to-care-for schooling fish and is peaceful towards other ornamental fish. These rainbowfish are best kept in a large, very spacious aquarium with plenty of free space to swim in.

The aquarium water should be hard and the pH value should be in the slightly alkaline range.

This fish is completely unsuitable for soft water. It is omnivorous, but a varied diet is important. It eats live, frozen and dry food.

  • Aquamarine rainbowfish reaches a maximum length of approx. 12 cm in the aquarium
  • In the aquarium, too, they should be kept as a swarm in an aquarium with a volume of 250 liters or more, which requires around 8 fish for this species.
  • Aquamarine rainbowfish feel most comfortable with the following water values: temperature 20 to 25 ° C, pH value 7.5 to 8.5 and total hardness 12 to 20 ° dGH. They are therefore unsuitable for soft water.
  • The aquarium for aquamarine rainbowfish should be planted in such a way that as much free swimming space as possible remains for the agile fish in addition to dense planting along the edges.
  • As food, Melanotaenia lacustris can get all common small to medium-sized types of food from the aquarium trade. Melanotaenia lacustris should have a varied diet.
Melanotaenia lacustris – Aquamarine Rainbowfish in Aquarium

In order to keep Melanotaenia lacustris (aquamarine rainbowfish) as species-appropriate as possible, it is recommended that you create the following conditions.

Especially when specifying the minimum size, we ask you to note that the optimal conditions may only be achieved in significantly larger aquariums.

  • Water temperature: 20 ° to 25 ° C
  • pH value: 7.5 to 8.5
  • Total hardness: 12 ° to 20 ° dGH
  • Minimum aquarium size: 250 liters

Melanotaenia lacustris (Aquamarine Rainbowfish): Breeding

Aquamarine rainbowfish are not tied to specific breeding times; they can spawn all year round. The males begin courtship in the morning when the morning sun shines into the pool. During the mating season, the forehead of the males turns yellow. The females prefer to lay their eggs on Java moss and other fine-feathered aquatic plants.

Melanotaenia lacustris (Aquamarine Rainbowfish): Other Facts

Aquamarine rainbowfish are perpetual spawners. This means that they spawn not only in a special season, such as other fish in the rainy season, but all year round when the conditions are favorable.

Melanotaenia lacustris is an omnivore. All types of live, frozen, flake or green fodder are taken in the aquarium. A varied diet is important.

In the morning, when either the light goes on in the aquarium or the daylight that falls in is bright enough, the males begin courtship. Her forehead turns bright yellow. As a spawning substrate they prefer slender plants close to the ground, for example Java moss in the aquarium.

Be the first to comment

Leave a Reply

Your email address will not be published.