Eastern Rainbowfish

Melanotaenia splendida

Animalia›Chordata›Actinopterygii›Melanotaeniidae

📍 Eastern Australia & New Guinea

Robust Australian rainbowfish with vivid red-orange flanks and iridescent scales. Very hardy and adaptable. A great community fish that colours up beautifully under good conditions.

Size4.5"

Min Tank30g

School6+

peaceful

Zonemid

Care Guide

Diet

Eastern Rainbowfish are omnivores that thrive on a varied diet of high-quality flake foods, small pellets, and regular offerings of frozen foods like brine shrimp, daphnia, and bloodworms. Feed small amounts once daily, providing only what they can consume in 2-3 minutes. Supplement with vegetable matter such as blanched spinach or spirulina-based foods to support coloration and overall health.

Behavior

These are active, schooling fish that spend most of their time in the mid-water column, constantly swimming and foraging. They are peaceful and social, displaying best colors and behavior when kept in groups of at least 6 individuals where they establish a loose hierarchy. Males may display mild fin-flaring to each other, but aggression is minimal and rarely causes injury.

Breeding

Breeding in captivity is moderately difficult and requires patience, as these fish are egg-scatterers with no parental care. Condition breeding pairs with live foods, provide fine-leaved plants or spawning mops, and maintain water temperatures around 26-27°C with slightly acidic to neutral pH. Expect 100-300 eggs per spawn; remove parents immediately after spawning to prevent egg predation, and fry will free-swim in 7-10 days.

Tank Mates

Emerald Dwarf Rasbora

Similar size, peaceful temperament, and mid-water swimming habits make them ideal companions

excellent

Rummy Nose Tetra

Comparable water requirements and peaceful schooling behavior; both thrive in groups

excellent

Dwarf Gourami

Peaceful mid-water dweller with similar temperature preferences; monitor for any territorial behavior

good

Bristlenose Pleco

Nocturnal algae-eater that doesn't compete for food or space in the mid-water zone

excellent

Red Cherry Shrimp

Small invertebrates that occupy different ecological niches; ensure adequate hiding spots for shrimp

good

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, rapid gill movement, fish rubbing against objects, lethargy

Treatment

Raise temperature gradually to 28-30°C, perform daily 25% water changes, use aquarium salt (1 teaspoon per 5 gallons) or commercial ich treatment; maintain treatment for 10-14 days

Fin Rot

Symptoms

Frayed or disintegrating fin edges, white or gray coloration on fin margins, progressive fin deterioration

Treatment

Perform 50% water change immediately, improve water quality and filtration, treat with antibacterial medication or salt baths; isolate severely affected fish if possible

Columnaris (Flexibacter columnaris)

Symptoms

Whitish film on body or fins, loss of appetite, lethargy, rapid gill movement, mouth erosion

Treatment

Increase aeration, perform daily 30% water changes, treat with antibacterial medication; maintain water temperature at 24-25°C and avoid stress factors

Velvet Disease (Oodinium)

Symptoms

Fine golden or rust-colored dust on body, rapid gill movement, scratching behavior, clamped fins

Treatment

Reduce light exposure, raise temperature to 28°C, treat with copper-based medication or salt; perform daily water changes and maintain treatment for 7-10 days