Crimson spot rainbowfish - Melanotaenia duboulayi

Scientific name: Melanotaenia duboulayi

Common name: Crimson spot rainbowfish

Family: Melanotaeniidae

Usual size in fish tanks: 8 - 9 cm (3.15 - 3.54 inch)

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Recommended pH range for the species: 6.5 - 7.5

Recommended water hardness (dGH): 5 - 10°N (89.29 - 178.57ppm)

0°C 32°F30°C 86°F

Recommended temperature: 22 - 25 °C (71.6 - 77°F)

The way how these fish reproduce: Spawning

Where the species comes from: Oceania

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

Food and Feeding

The Crimson Spot Rainbowfish (Melanotaenia duboulayi) is an omnivorous species that will readily accept a variety of foods in captivity. Their staple diet should include high-quality flakes or pellets designed for tropical fish, as these provide the essential nutrients needed for their vibrant colors. Additionally, offering live or frozen treats such as bloodworms or brine shrimp once a week will enhance their health and coloration. They may also enjoy small vegetable-based foods, like blanched spinach or spirulina-based flakes, which aid in digestion and provide variety. Crimson Spot Rainbowfish should be fed small amounts twice daily to prevent overeating and maintain water quality. Rotating their diet helps provide variety and prevent boredom, while occasional treats of small insects or larvae, such as daphnia, can help stimulate natural foraging behaviors.

Origin

The Crimson Spot Rainbowfish is native to eastern Australia, particularly in freshwater rivers and streams of New South Wales and Queensland. In the wild, these fish inhabit slow-moving waters that are often densely vegetated, providing natural cover and supporting a healthy population of small invertebrates and algae, essential parts of their diet. They also experience seasonal changes, such as an increase in natural food sources and cooler water during the rainy season. This change can be mimicked in captivity by adjusting the temperature slightly and varying their diet seasonally to help encourage natural behaviors and vibrant coloration.

Sexing

Sexing Crimson Spot Rainbowfish is relatively straightforward. Mature males display red stripes along their bodies, and their dorsal, anal, and caudal fins feature distinct red spots. During breeding displays, males develop a striking black margin on all their fins, adding to their vibrant appearance. Females, by contrast, have clear fins and a more subdued coloration, making them easier to distinguish from males. Additionally, during breeding periods, males may display more active or territorial behavior, making it easier to identify potential mates in a group setting.

Breeding

Breeding Melanotaenia duboulayi is achievable in a home aquarium with the right conditions. A well-planted tank is ideal, as plants provide shelter and suitable spawning sites. Using spawning mops as additional breeding sites can also encourage spawning. Typically, spawning occurs at dawn, when the fish scatter their eggs among plants or mops. To encourage breeding, maintain slightly softer water with a pH closer to neutral, around 6.5-7.0, and increase the temperature to the upper range of their comfort zone, around 25°C (77°F). Regular partial water changes and feeding live or frozen foods can also trigger spawning behavior by simulating conditions in their natural habitat. Once the eggs are laid, it is essential to remove the parents from the tank to prevent them from consuming the eggs. The eggs generally hatch within a week, and the tiny fry can initially be fed infusoria. As they grow, switch to feeding them newly hatched brine shrimp to support healthy development.

Lifespan

With proper care, Melanotaenia duboulayi can live for approximately 3-4 years. Providing stable water conditions, a balanced diet, and a peaceful environment are essential for promoting their health and longevity in captivity. Although the average lifespan is 3-4 years, they may live longer with a well-maintained tank and compatible tank mates. Avoiding overly aggressive species and high-stress environments is crucial for their well-being.

Short Description

The Crimson Spot Rainbowfish, also known as Melanotaenia duboulayi, is a peaceful and sociable species that thrives in groups. They are best kept in schools of six or more, where they can display natural social behaviors and feel secure. However, when kept with other rainbowfish species, crossbreeding is likely to occur, which can result in hybrids. For this reason, many aquarists prefer to keep Crimson Spot Rainbowfish in a species-specific tank. A spacious tank with open swimming areas and some planted sections is ideal. Their peaceful nature makes them suitable for mixed community tanks, but they truly thrive in species-only setups where their unique colors and interactions can shine. Their stunning colors and active schooling behavior make them a popular choice for aquarists looking to add a touch of brilliance to a well-maintained tank.