Turquoise Rainbow (2-2.5”)

Scientific Name: Melanotaenia lacustris

• Size: 4.5–5 inches (11–13 cm)

• Lifespan: 6–8 years, occasionally longer with excellent care

• Minimum Tank: 40 gallons for a small group. 75+ Gallon is recommended for larger groups/community setup. They also prefer long tanks with open swimming space and moderate flow

• Temperature: 74–80°F (23–27°C)

• pH: 7.0–8.0

• Water Changes:

  • 30–40% weekly recommended

  • Stable water quality is essential; they are sensitive to poor maintenance

• Strong oxygenation and clean water; they thrive in moderate to high flow

General Care Notes:
Turquoise Rainbows are active, hardy, and colorful, but they exhibit the best coloration when kept in clean water and in large social groups. Provide open areas for swimming plus tall plants to give them security. They can be jumpy—use a tight lid.

Tankmates:

• Other Larger Species of Rainbowfish , Congo Tetras, Clown Loaches,          Small-Medium Sized Barbs, Larger Livebearers, Corydoras, Gouramis (non-aggressive species)

Avoid:

• Slow, long-finned fish (may outcompete them at feeding)

• Very small nano fish (may be too timid or seen as prey)

• Aggressive cichlids

Diet

Turquoise Rainbows are omnivores with a strong preference for protein-rich foods.

Recommended Diet:

• High-quality flakes or micro-pellets for daily feeding

• Frozen or live foods: brine shrimp, bloodworms (Feed 1-2 Times Weekly)

• Vegetable matter: spirulina based foods

Feed small portions 1-2 times daily to mimic natural grazing behavior and improve color.

Overview

The Turquoise Rainbowfish is one of the most striking Melanotaenia species, known for electric blue-green coloration, deep-bodied shape, and active midwater schooling.  Their peaceful nature, hardiness, and constant activity make them ideal for medium- to large-sized community aquariums.

Natural Environment

Native to Lake Kutubu and the Soro River system in Papua New Guinea, Turquoise Rainbows inhabit clear, sunlit freshwater lakes and rivers with abundant vegetation. Waters are alkaline, hard, and extremely clean. The species is accustomed to open swimming areas with submerged plants along the margins.

Breeding

Turquoise Rainbows are typical egg scatterers.

Breeding Requirements:

• Separate spawning tank around 20–30 gallons

• Fine-leaf plants or spawning mops for egg deposition

• Slightly higher temperature (78–80°F / 25–27°C)

• Soft to medium water aids hatching but not strictly required

Process:

• Condition adults heavily with live foods

• A pair or small group will scatter eggs daily over 1–2 weeks

• Remove adults after eggs appear; they may eat them

• Eggs hatch in 6–12 days depending on temperature

• Fry are tiny; feed with infusoria, green water, then baby brine shrimp

Color develops gradually and becomes impressive by 6–9 months.