Macculloch's Rainbowfish (Melanotaenia maccullochi) Care Guide
Melanotaenia maccullochi is a small striped rainbowfish from northern Australia and New Guinea, an aquarium classic since its 1915 description.
Compiled by Aquairi from published sources · Published · Updated
Overview
Melanotaenia maccullochi is a small rainbowfish of the family Melanotaeniidae, reaching about 7-7.5 cm. It was described in 1915 by James Douglas Ogilby, who named it after the ichthyologist Allan Riverstone McCulloch, and it has been kept in the aquarium hobby ever since. The silvery body carries several dark longitudinal stripes, with males more vividly coloured than females.
Taxonomy
- Family: Melanotaeniidae
- Genus: Melanotaenia
- Scientific name: Melanotaenia maccullochi
Habitat
Found across northeastern Australia and Papua New Guinea in swamps, streams and creeks. FishBase notes lowland swamps and small streams with clear, acidic water and plenty of cover from logs or vegetation, with natural pH around 5.5-7.0.
Tank requirements
- Minimum tank volume: 100 L
- Temperature: 22-28 °C (72-82 °F)
- pH: 6.5-7.5
- GH: 8-20 °dGH
- School size: 8 or more individuals
- Lifespan: 4-6 years
Diet
An omnivore: Wikipedia reports a wild diet of aquatic invertebrates, algae and terrestrial invertebrates. In captivity it readily accepts frozen foods, flakes and granules.
Compatibility
A peaceful, small mid-water schooler suited to community aquaria. Keep in groups of eight or more alongside other peaceful species such as small catfish and tetras.
Breeding
Wikipedia notes the species breeds readily in captivity. Spawning occurs in the early morning, with the pair pressing together and trembling as eggs are deposited among aquatic plants; sexual maturity is reached at about five months and 3 cm.
Conservation status
IUCN Red List: Least Concern (assessed 2019).
Breeding Maria's Rainbowfish (Melanotaenia maccullochi)
Overview
Melanotaenia maccullochi is found in Papua New Guinea and Australia across habitats ranging from clear streams to tannin-stained ponds, reaching a maximum standard length of about 7 cm. Seriously Fish describes it as not a difficult species to breed, being an egg-scatterer, although the fry can prove somewhat tricky to raise.
Sexing
Males display more vibrant colouration and have elongated dorsal and anal fins, while females have a deeper body shape and stay plainer. The intensified colour and extended finnage of males make a conditioned spawning group easy to read.
Conditioning
The adults are best conditioned as a group in a separate aquarium with plenty of live and frozen foods. Good conditioning fills the females out and brings the males into constant display before spawning.
Breeding Setup
- Spawning occurs over fine-leaved plants or synthetic spawning mops, with no substrate required.
- A separate, well-oxygenated tank with gentle air-driven filtration works well.
- Keep the water clean and stable throughout the extended spawning period.
Spawning Behavior & Trigger
Pairs produce eggs daily over several weeks, with the eggs attached to surfaces by a small thread among the plants or mop. Rather than a single mass spawn, females release a steady trickle of eggs across the spawning period.
Egg & Fry Care
The eggs hatch in 7-12 days depending on temperature. The fry initially require infusoria-type foods before transitioning to free-swimming foods such as brine shrimp nauplii after about one week.
Common Challenges
Although spawning is easy, the small fry can be tricky to raise and depend on suitably tiny first foods and clean water. Moving the spawning medium to a rearing tank protects eggs and fry from hungry adults. Because the species ranges across very different waters in the wild, from clear streams to tannin-stained ponds, it adapts to a fairly broad range of clean, stable aquarium conditions for breeding rather than demanding one narrow profile, which makes consistent water quality and conditioning, rather than exotic chemistry, the main keys to success.