Sahul rainbowfish

Melanotaenia sahulensis

Also known as Sahul dwarf rainbowfish, Skull Creek rainbowfish

FreshwaterFish

Sahul rainbowfish (Melanotaenia sahulensis) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 75–86°F (24–30°C)
pH: 6.5–7.8
Adult size: 2.2 in (5.5 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Southern New Guinea and northern Australia lowlands
Family: Melanotaeniidae

Overview

A dwarf rainbowfish for a small planted community, kept in a group of a dozen small fish so the shoal looks its best and the males have rivals to display to. It is peaceful and suits other small, gentle tankmates rather than large or pushy fish. Feed fine foods: crushed flake, small granules, and frozen or live daphnia, cyclops, and baby brine shrimp. A group is happy in around 75 liters with dense planting and open patches of water to swim through.

In the wild

The Sahul rainbowfish lives in shallow, swampy lowland waters on both sides of the Torres Strait, across the northern tip of Cape York in Australia and into southern New Guinea. Keep it at 24 to 30 degrees Celsius in soft to moderately hard water around neutral, a pH of 6.5 to 7.8. A well-planted tank with a soft bottom, leaf litter or wood, and quiet open water suits it.

Good to know

Melanotaenia sahulensis, family Melanotaeniidae, was described in 2019 among the dwarf rainbowfishes split from the Macculloch's rainbowfish complex, and it stays around 5.5 centimeters. It is named for Sahul, the ancient landmass that joined Australia and New Guinea. Breeding is of medium difficulty, the fish scattering adhesive eggs among fine plants or mops daily.

Did you know

Its range spans two countries because it is older than the sea between them: the species was once continuous across Sahul, the Ice Age landmass that joined Australia and New Guinea before rising seas flooded the Torres Strait.