Lake Kutubu Rainbowfish (Melanotaenia lacustris) Care Guide

A stunningly beautiful rainbowfish with a two-toned blue body — deeper cobalt on top fading to lighter turquoise below. Endemic to Lake Kutubu in Papua New Guinea.

Overview

Melanotaenia lacustris is a species in the family Melanotaeniidae. A stunningly beautiful rainbowfish with a two-toned blue body — deeper cobalt on top fading to lighter turquoise below. Endemic to Lake Kutubu in Papua New Guinea. Males intensify in color during displays. One of the most sought-after rainbowfish species.

Taxonomy

Family: Melanotaeniidae
Genus: Melanotaenia
Scientific name: Melanotaenia lacustris
Other names: Turquoise Rainbowfish, Blue Rainbowfish
Origin: Oceania

Habitat

Endemic to Lake Kutubu and its outflow into the Soro River in the Southern Highlands Province of Papua New Guinea, at about 800 m elevation. Listed as Vulnerable on the IUCN Red List; threatened by introduced fishes and watershed development.

Tank requirements

Minimum tank volume: 150 L
Temperature: 22-26 °C
pH: 7-8.5
GH: 8-20 °dGH
Water flow: moderate
Adult size: 8-12 cm
Lifespan: 5-8 years
Recommended group size: ≥ 6
Difficulty: intermediate

Diet

Classified as omnivore. Recommended feeding frequency: 2x daily. In captivity, offer a varied diet appropriate to the species — quality prepared foods supplemented with frozen or live items of suitable size.

Compatibility

Temperament: peaceful
Swimming level: middle
Compatible tank mates: Other Rainbowfish, Corydoras, Large Tetras
Avoid with: Aggressive Fish, Very Small Fish

Breeding

Breeding strategy: egg-scatterer
Breeding difficulty: intermediate