Western Rainbowfish

Melanotaenia australis

Animalia›Chordata›Actinopterygii

📍 Australia

A rainbowfish native to rivers in Western Australia, displaying a silvery body with a reddish stripe and blue-green iridescence that varies with lighting; males develop deeper coloration. Hardy and adaptable to a broad pH and temperature range, it is peaceful and does best in schools of 6+ in a well-planted tank of 30+ gallons.

Size4"

Min Tank30g

School4+

peaceful

Zonemid

Care Guide

Diet

Western Rainbowfish are omnivorous and thrive on a varied diet of high-quality flake foods, small pellets, and regular offerings of frozen foods such as brine shrimp, daphnia, and bloodworms. Feed once daily in small portions that can be consumed within 2-3 minutes; they will also graze on algae and plant matter in the tank.

Behavior

These are active, schooling fish that spend most of their time in the mid-water column, displaying vibrant colors especially when kept in groups of 6 or more. Males exhibit competitive displays and color intensification around other males, but remain peaceful toward other species; they are most active during daylight hours and appreciate open swimming space.

Breeding

Breeding in captivity is possible but requires patience and specific conditions including dense plants or spawning mops, slightly elevated temperatures (26-27°C), and excellent water quality. Eggs are typically scattered among plants and hatch in 7-10 days; fry are small and require infusoria or liquid fry food initially. Breeding is moderately difficult for beginners.

Tank Mates

Emerald Dwarf Rasbora

Similar size, peaceful temperament, and mid-water swimming zone; compatible water parameters

excellent

Rummy Nose Tetra

Peaceful schooling fish with overlapping pH/temperature range and similar size

excellent

Sterbai Corydoras

Bottom-dweller that doesn't compete for space; tolerates the same water conditions

good

Bristlenose Pleco

Peaceful algae eater that occupies different tank zone; hardy and compatible with rainbowfish

good

Boesemani Rainbowfish

Closely related species with identical care requirements; compatible schooling behavior

excellent

Red Cherry Shrimp

May be preyed upon by larger rainbowfish; best in heavily planted tanks with plenty of hiding spots

caution

Common Diseases

Ich (Ichthyophthirius multifiliis)

Symptoms

White spots on body and fins, flashing against objects, rapid breathing, lethargy

Treatment

Raise temperature gradually to 28-29°C, perform daily 25% water changes, use aquarium salt (1 teaspoon per 5 gallons) or commercial ich treatment; maintain for 10-14 days

Fin Rot

Symptoms

Frayed or deteriorating fin edges, discoloration at fin bases, progressive fin loss

Treatment

Improve water quality with frequent partial water changes, reduce stocking density, treat with antibacterial medication if severe; ensure adequate filtration and avoid sharp decorations

Columnaris (Flexibacter columnaris)

Symptoms

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

Treatment

Perform large water changes immediately, raise temperature to 28°C, treat with antibacterial medication; isolate affected fish if possible and improve tank conditions