Taxonomy & naming
This is an undescribed form: no scientific name, authority or type material stands behind it, and its identity and range are not documented in the sources the atlas uses. "Kali Biru" is a locality-style trade label for a New Guinea population, placed in Melanotaenia by the seller. Which drainage it belongs to is not documented in the atlas's sources.
Morphology
Imperial Tropicals says the Kali Biru form has a bright orange dorsal stripe running from the nose to the first dorsal fin, and that rainbowfish colour patterns vary a great deal with catch location.
Habitat
Imperial Tropicals says Melanotaenia are found throughout New Guinea, in populations separated by barriers such as waterfalls and dried river sections. It says the Kali Biru fish were collected in a lake with clear water, a pH of about 7.8 and fairly low conductivity, and that the strain in the trade descends from eggs collected there. These are seller statements; the atlas holds no independent record.
Feeding
Rainbowfishes are omnivores that take small invertebrates and plant material (genus-level). Imperial Tropicals recommends a quality flake food with supplements such as baby brine shrimp.
Mating
Melanotaenia spawn over fine-leaved plants or spawning mops, with males displaying to females (genus-level).
Breeding
The strain sold today comes from eggs collected from the lake, according to Imperial Tropicals. Breeding behaviour of the form is not described beyond the genus pattern of egg-scattering over fine plants.
In the aquarium
The seller's collection note gives clear water with a pH around 7.8 and low conductivity. No adult size or temperature range is given in the text the atlas holds.
Conservation
No IUCN assessment exists for this undescribed form. Its range and numbers are not documented, so its conservation status cannot be stated.