The Neon Blue Rasbora, scientifically known as Sundadanio axelrodi, is a captivating and relatively small species of freshwater fish native to the slow-moving streams and blackwater habitats of Southeast Asia, particularly in Indonesia. This species is highly prized by aquarists for its vibrant coloration, peaceful demeanor, and active schooling behavior, making it an excellent addition to well-maintained community aquariums, especially nano tanks.

Neon Blue Rasboras are characterized by their small, slender bodies and striking blue coloration. Their bodies typically display a shimmering blue or blue-green hue, often with iridescent highlights that reflect light beautifully. Males are generally more colorful than females, with brighter and more intense hues. Their fins are usually clear or slightly tinted, adding to their delicate and attractive appearance.

In captivity, Neon Blue Rasboras thrive in aquariums that closely mimic their natural blackwater habitat. A tank setup should include a soft, sandy substrate and plenty of live plants, such as Java moss, Anubias, and floating plants, which provide cover and create a comfortable environment. Adding driftwood and leaf litter can help replicate the tannin-rich waters they are accustomed to, enhancing their colors and providing additional hiding spots.

Water conditions should be slightly acidic to neutral, with soft to moderately hard water. Maintaining stable water parameters through regular water changes and efficient filtration is crucial for the health and well-being of Neon Blue Rasboras. They are relatively hardy fish but do best in clean, well-oxygenated water.

Neon Blue Rasboras are social fish that should be kept in groups of at least six or more to promote their well-being and natural schooling behavior. Keeping them in a school not only reduces stress but also enhances their vibrant colors and active swimming patterns. They are peaceful and can be housed with other small, non-aggressive fish, making them ideal for community tanks.

Their diet should be varied to ensure they receive all necessary nutrients. Neon Blue Rasboras are omnivorous and will readily accept high-quality micro pellets, flake foods, and live or frozen foods such as brine shrimp, daphnia, and micro worms. Providing a mix of these foods will help maintain their health, vibrant colors, and energetic behavior.

Breeding Neon Blue Rasboras in captivity can be challenging due to their specific environmental needs. They are egg scatterers, typically laying their eggs among fine-leaved plants. To encourage breeding, maintain optimal water conditions with slightly acidic, soft water and provide plenty of fine-leaved plants or spawning mops. Once spawning occurs, it is advisable to remove the adults from the breeding tank to prevent them from eating the eggs. The eggs usually hatch within a few days, and the fry can be fed with infusoria or finely crushed flake food until they are large enough to accept standard fare.

Overall, the Neon Blue Rasbora is an excellent choice for aquarists looking for a small, colorful, and peaceful species. Their striking appearance, gentle nature, and dynamic behavior make them a delightful addition to any well-maintained aquarium. With proper care and the right environment, they can thrive and bring a touch of vibrant beauty and lively activity to your aquatic setup.