Western Rainbowfish - Melanotaenia australis : Complete Fish Profile & Care Guide
Table of contents
Introduction
The Western Rainbowfish (Melanotaenia australis) is a captivating medium-sized species renowned for its peaceful nature, making it a beloved choice among enthusiasts of Rainbowfish. Furthermore, its remarkable adaptability renders it suitable even for novice aquarists, cementing its popularity in the hobbyist community. Flourishing within planted community aquariums, these vibrant fish radiate a captivating presence that adds vibrancy to any aquatic ensemble.
To ensure the optimal well-being of Western Rainbowfish, it is imperative to maintain them in groups of six or more, honouring their inherent shoaling tendencies. Furthermore, creating a harmonious gender ratio by housing multiple females for each male enhances their social dynamics. These charismatic fish demand a spacious habitat that allows them to engage freely in their energetic behaviours, underscoring their propensity for activity.
While Western Rainbowfish boast an extraordinary colouration, it is essential to note that the nuances of their appearance can significantly vary based on their geographic origin. The captivating interplay of their fins and the intensity of the mid-lateral stripe serve as a testament to the rapid speciation witnessed within the rainbowfish group. Moreover, the intricate tapestry of morphological variation among distinct populations further enriches their visual diversity.
The striking body of Western Rainbowfish typically features one to two broad, dark mid-lateral stripes, adorned with a succession of thin longitudinal stripes displaying hues of radiant orange-red, harmoniously aligned with each scale row. In addition, an iridescent sheen of purple or blue envelops their entire physique, weaving an enchanting tapestry of colour. From nearly colourless to deep red or translucent with red or green flecks, the fins of these magnificent creatures exhibit an awe-inspiring spectrum of possibilities. The second dorsal and anal fins boast rays imbued with a reddish-orange hue, accompanied by a yellow membrane and a resolute dark distal border.
While females resemble their male counterparts in body colouration, their delicate femininity manifests through a paler hue, devoid of the striking dark mid-lateral band and the zigzag stripes that grace the lower portion. Notably, the females' first dorsal spines remain modest in length, refraining from extending towards the origin of the second dorsal fin. Additionally, their anal and second dorsal fins lack the elongated posterior rays, exhibiting a more compact and rounded fin structure.
Western Rainbowfish Photos
Sexual Dimorphism
Distinguishing between male and female Western Rainbowfish is a straightforward task. However, the males of this species exhibit distinct characteristics that differentiate them from the females. Typically, the males boast a vibrant and visually striking colouration, surpassing the females in terms of size and body depth. Moreover, they possess elongated dorsal and anal fins, further contributing to their notable appearance.
Quick Facts
| Scientific Name | Melanotaenia australis |
|---|---|
| Year Described | 1878 |
| Other Names | Australian Rainbowfish, Northern Rainbowfish, Red-tailed Rainbowfish, Western Australian Jewel-fish, Western Australian Sun-fish |
| Kingdom | Animalia |
| Classification | Actinopterygii |
| Order | Atheriniformes |
| Family | Melanotaeniidae |
| Genus | Melanotaenia |
| Origins | Australia |
| Max Size | 12 cm |
| Temperament | Peaceful |
| Aquarium Level | Middle - Top |
| Difficulty | Beginner - Intermediate |
| Shoaling | Yes |
| Best kept as | Groups 6+ |
| Diet & Feeding | Omnivore |
| Reproduction | Egg Depositor |
| Average Lifespan | Up to 5 Years |
Water Parameters
| Water Type | Freshwater |
|---|---|
| pH | 6.0 - 8.0 |
| GH | 5 - 20 |
| ℉ | 72 - 82 |
|---|---|
| ℃ | 22 - 28 |
Natural Habitat
The Western Rainbowfish is a captivating inhabitant of the River systems in northwestern Australia. Its presence can be witnessed in diverse locations, stretching from the Ashburton River in the west to the vibrant Kimberley region and the northwestern reaches of the Northern Territory. As it journeys further east, the Daly River becomes its home, showcasing the remarkable adaptability of this incredible species.
These enchanting Rainbowfish have chosen their abodes carefully, favouring the sub-surface vegetation, hidden logs, and branches that adorn the small tributary streams. However, their adventurous nature also leads them to explore the depths of swamps and lagoons. Within these underwater wonderlands, they create grand gatherings, joining together amidst the margins adorned with lush vegetation and the intriguing maze of submerged logs and branches.
Nature's whims paint a dynamic canvas for these Rainbowfish, subjecting them to the ebb and flow of the seasons. As the dry season takes hold, water conditions undergo a metamorphosis, with temperatures, pH levels, and hardness undergoing significant transformations. When the rains drench the land, a symphony of change unfolds, reshaping their aquatic playground and ushering in a new chapter of life in the wet season.
Breeding
To successfully breed Western Rainbowfish, it is advisable to establish a dedicated breeding aquarium of substantial size equipped with a gentle air-driven sponge filter that ensures appropriate water circulation and filtration. Once the breeding aquarium is prepared, a group consisting of three females and two males should be carefully acclimated to their new environment.
The aquarium should be thoughtfully adorned with an abundance of fine-leaved plants or clusters of Java moss, providing the essential spawning substrate. In due course, a male will initiate courtship by positioning himself in front of a female, engaging in an elaborate display. This display is often followed by the male guiding the female across the expanse of plants, utilizing the entire length of the tank in an intricate spawning ritual.
Western Rainbowfish are known as "continual spawners," a characteristic that manifests through the occurrence of spawning over several days or even weeks. This prolonged spawning behaviour can challenge aquarists, as some adult fish may consume freshly laid eggs. However, diligent feeding practices can help mitigate this issue, ensuring the adults are well-nourished and less inclined to prey upon the eggs.
Many experienced fishkeepers have discovered that the eggs of Western Rainbowfish exhibit remarkable durability. As a result, successful breeding endeavours have been achieved by siphoning the eggs into a separate aquarium or utilizing specialized spawning mops. Employing spawning mops allows for the accessible collection of a batch of eggs, which can then be transferred to a dedicated rearing tank. Subsequently, the mop can be replaced with a fresh one to facilitate the deposition of subsequent batches of eggs.
Under optimal conditions, the eggs of Western Rainbowfish will typically hatch within 8 to 11 days, influenced by the prevailing water temperature. Once the fry has become free-swimming, their nutritional needs can be met with an initial diet of infusoria. As the fry progresses in their development, their dietary requirements can be gradually shifted to accommodate larger food sources.
Diet & Feeding
Western Rainbowfish exhibit an unfussy omnivorous diet, readily accepting a wide range of food options. These versatile fish will readily consume various types of dried, frozen, and live foods. By offering a diverse and balanced diet, you can ensure optimal colouration and overall health for your Rainbowfish.
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