Goldie River Rainbow - Melanotaenia cf. goldiei (Dekai)

Goldie River Rainbowfish – Dekai (Melanotaenia cf. goldiei “Dekai”)

The Goldie River Rainbowfish – Dekai, Melanotaenia cf. goldiei “Dekai”, is a larger New Guinea rainbowfish locality form valued for its active shoaling behaviour, metallic body sheen and colourful mature males. Depending on age, mood and lighting, males may show blue, green, gold, orange or red tones with stronger fin colour and a deeper body shape as they mature. This is a peaceful but energetic rainbowfish best suited to spacious planted aquariums with open swimming room, excellent water quality and a proper group.

Common Name:
Goldie River Rainbowfish – Dekai, Goldie Rainbowfish Dekai, Dekai Goldiei Rainbowfish, Goldie River Rainbowfish.

Scientific Name (Latin):
Melanotaenia cf. goldiei “Dekai”
Closely related to, or a locality form of, Melanotaenia goldiei.

Maximum Size:
Usually around 10–12 cm in aquariums, with larger mature males becoming deeper-bodied. FishBase lists Melanotaenia goldiei at up to 11.5 cm standard length.

Water Type:
Freshwater

Origin / Natural Habitat:
New Guinea. Melanotaenia goldiei is a widespread New Guinea rainbowfish associated with swamps, backwaters, tributary streams and large rivers. The Dekai form is a locality/trade strain and should not be mixed with other Goldie Rainbowfish localities if breeding purity is important.

Water Parameters:
Temperature: 24–28°C
pH Range: 7.0–8.0
Hardness or Salinity: Moderately soft to moderately hard freshwater; stable, clean water with good oxygenation is important.

Temperament:
Peaceful, active and sociable. Goldie Rainbowfish are not aggressive, but they are fast swimmers and can intimidate very shy nano fish simply through activity. They are best kept in groups so males can display naturally and the fish feel secure.

Diet:
Omnivorous. Offer quality flakes, small floating or sinking pellets, granules, frozen daphnia, brineshrimp, mysis, cyclops, mosquito larvae and occasional live foods. Some plant-based or spirulina foods can also be included. A varied diet helps maintain colour, body condition and display behaviour.

Minimum Tank Size:
A minimum of 250 litres is recommended for a group, with larger aquariums preferred. A long aquarium with open swimming lanes is much better than a small or tall-only setup.

Behaviour & Activity:
An active mid-to-upper level shoaling rainbowfish that spends much of its time swimming in open water and displaying among its own kind. Keep at least 6 individuals, with 8–10 or more preferred for confidence and natural behaviour. Mature males may become deeper-bodied and show stronger colour when kept with females. Like other rainbowfish, this species scatters eggs among fine-leaved plants, mosses or spawning mops and does not guard them.

Aquarium Category:
Community Fish
Suitable with other peaceful medium-sized community fish such as rainbowfish, larger tetras, peaceful barbs, rasboras, Corydoras-type catfish, non-aggressive loaches, bristlenose plecos and calm cichlids that enjoy similar water conditions. Avoid very tiny fish that may be intimidated, aggressive cichlids, fin-nippers, very slow feeders and cramped aquariums.

Special Requirements or Care Notes:
Provide a mature, well-filtered aquarium with open swimming space, planted margins, wood, rocks and shaded retreats. Regular water changes, good oxygenation and stable conditions are important for long-term health. Young fish can look comparatively plain, but mature males colour up strongly with age, good diet and settled group dynamics. Keep locality forms separate if breeding, as rainbowfish localities can hybridise or lose their distinct line identity if mixed.

Suitable for:
Intermediate fishkeepers

Availability:
Rare or occasional in trade / Specialist rainbowfish locality strain

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.