Profile Photo

Maximum size : 7 cm

Redfin Dwarf Rainbowfish - Melanotaenia maccullochi : Complete Fish Profile & Care Guide

Table of contents


Redfin Dwarf Rainbowfish (Melanotaenia maccullochi) are a favourite amongst aquarists due to their peaceful nature, adaptability to varying water conditions, and striking appearance. These hardy fish are best kept in a shoal of 6 or more to encourage the males to display their brightest colours. It is crucial to avoid housing Redfin Dwarf Rainbowfish with aggressive species as they can struggle to compete for food and may become stressed. Instead, they do well in a species-only tank or a peaceful community aquarium with other small and non-aggressive fish. These fish typically have brownish-bronze colouring on the upper half of their body and white to brownish colouring on the lower half. They display seven or eight lateral body stripes, with some being continuous and others broken, especially in younger fish. Their fins range from light yellow to orangey-red, with some displaying brown spots or lines.

Redfin Dwarf Rainbowfish Photos

Sexual Dimorphism

It is a relatively simple task to distinguish between the male and female Redfin Dwarf Rainbowfish. Sexually mature males exhibit more vibrant colors than their female counterparts, with longer dorsal and anal fins and more robust bodies. When in breeding condition, the male's colors become more pronounced, featuring prominent body stripes and intensified red fin coloration.

Quick Facts

Scientific NameMelanotaenia maccullochi
Year Described1915
Other NamesMacculloch's Rainbowfish, Dwarf Rainbowfish, Red-finned Rainbowfish
OriginsPapua New Guinea Australia
Max Size7 cm
Aquarium LevelMiddle
DifficultyBeginner - Intermediate
Best kept asGroups 6+
Lifespan3 - 5 years

Water Parameters

Water TypeFreshwater
PH5.5 - 7.5
GH8 - 15
68 - 86
20 - 30

Natural habitat

The Redfin Dwarf Rainbowfish is a captivating species that is indigenous to various regions in Northern Australia, including Papua New Guinea. These fish thrive in diverse aquatic habitats, ranging from clear, fast-flowing streams and creeks to muddy ponds stained with tannins and grassy lowland swamps. Their adaptability to the diverse water chemistry of their environment is remarkable. Seasonal variations significantly influence the natural habitats of this species. You will usually find these fish gathering around shallow water areas with low turbidity that feature a dense cover of submerged or emergent vegetation, such as logs and branches, as well as aquatic plants.

How to breed the Redfin Dwarf Rainbowfish

The breeding of Redfin Dwarf Rainbowfish is a fairly straightforward process, but the fry rearing can pose some challenges. To breed them, a separate breeding tank heavily planted with fine-leaved plants or spawning mops is necessary. The water should be slightly alkaline and somewhat hard with a temperature a few degrees higher than their usual range. An air-driven filter will ensure sufficient flow and oxygenation for optimal breeding conditions. Before breeding, it's essential to condition the fish with a high-protein diet consisting of frozen or live foods for about two weeks, simulating the flood season when they naturally spawn. When the males start displaying their vivid colours, and the females become plumper, it's a sign they are ready to mate. Select the best-looking male and the healthiest female and place them in the breeding tank. The mating pair will spawn for several days, with the male leading the female to a spawning area where she will lay eggs and attach them to plants or other surfaces with a tiny thread. The male will fertilize the eggs, and this process will continue until the female is depleted of eggs. To maximize results, it's best to check the plants or spawning mops daily for eggs and remove them to a separate grow-out tank to prevent consumption by the parents. Around seven to twelve days after the eggs are laid, they will hatch into tiny fry. For the first week, infusoria-type foods are recommended, and after that, they can consume small live foods such as brine shrimp or nauplii.

Diet & feeding

The feeding habits of Redfin Dwarf Rainbowfish are relatively simple as they are known to accept a broad range of high-quality dried foods, including flakes, green flakes and micropellets, as well as frozen and live foods such as mosquito larvae and daphnia. Nonetheless, to keep these fish in optimal health and vibrancy, it is highly recommended to provide them with several small feedings throughout the day instead of one large meal.

Other Rainbowfish you maybe interested in