Western Rainbowfish

The western rainbowfish was long known as a subspecies of Melanotaenia splendida (M. s. australis) and was later recognized as a separate species. It carries a blue-green sheen on its silvery body, thin orange-red stripes along its sides and reddish fins with dark edges. It grows to 8–10 cm.

The colors of populations living in the disconnected river systems of northwestern Australia differ markedly; for this reason it is also sold in the hobby under the name of the place where it was collected. It is a very hardy species that adapts to a wide range of water values and breeds easily.

It lives in the rivers of the Kimberley and Pilbara regions, in their spring-fed pools and in pools that shrink during the dry season. In these regions water temperature and hardness vary greatly with the season; the species has adapted to these fluctuations.

• Volume: at least 150 liters and 100–120 cm in length for a school of 6–10.
• Water: 24–27°C, neutral to slightly alkaline, moderately hard water; it has a wide tolerance. 25–30% water changes every week.
• Decor: Plants, roots and rocks along the edges; plenty of swimming space in the middle.
• Lighting: Good lighting and a dark substrate make the orange stripes stand out.
• Lid: It jumps; the lid must fit tightly.

Omnivorous and not fussy. It is fed quality flakes and granules, frozen brine shrimp, mysis, bloodworms and daphnia; foods with plant content support digestion. Feed small amounts 2–3 times a day.

Peaceful, active and curious. Males display to each other; during this their colors darken and a light-colored stripe appears on the forehead. Because it has a big appetite, it leaves slow fish behind at feeding time; it eats shrimplets.

Good companions: rainbowfish from other genera, medium-sized tetras, peaceful barbs, corydoras, bristlenose plecos, botias.

Avoid: slow long-finned fish, aggressive cichlids; if you plan to breed, other Melanotaenia species.

At least 6, ideally 10 or more individuals. A female-heavy group (2 females per male) is balanced. Having several males increases display behavior and color; in a large school the fish become bolder.

An easy-breeding egg scatterer. With the morning light, pairs lay a few eggs every day on fine-leaved plants or a wool spawning mop. Move the eggs, which have sticky threads, to a separate container; the parents eat eggs and fry. The fry hatch in 7–12 days; start with infusoria and liquid fry food, then move on to newly hatched brine shrimp.

Hybridization: It hybridizes easily with the eastern rainbowfish (M. splendida) and other Melanotaenia species. Do not mix different locality forms either; pass on the fry with information on their origin.

• White spot: can appear after a sudden temperature drop.
• Bloating: caused by overfeeding.
• Fading color: a sign of stress and poor water.
• It is one of the hardiest species in the group.

Males are larger, deeper-bodied and more colorful; their orange-red stripes are distinct, and their fins are reddish with dark edges. Females are smaller and slender; the stripes on their silvery bodies are faint, and their fins are colorless or slightly yellowish.