Mosquito rasbora - Boraras brigittae

Scientific name: Boraras brigittae

Common name: Mosquito rasbora

Family: Cyprinidae

Usual size in fish tanks: 3 - 4 cm (1.18 - 1.57 inch)

014

Recommended pH range for the species: 6.3 - 7

Recommended water hardness (dGH): 5 - 14°N (89.29 - 250ppm)

0°C 32°F30°C 86°F

Recommended temperature: 23 - 27 °C (73.4 - 80.6°F)

The way how these fish reproduce: Spawning

Where the species comes from: South Asia

Temperament to its own species: peaceful

Temperament toward other fish species: peaceful

Usual place in the tank: Middle levels

Origin

Mosquito Rasboras (Boraras brigittae) are native to the lush, slow-moving waters of South West Borneo in Asia. These small fish thrive in the blackwater streams and peat swamps, where the water is typically soft, acidic, and stained with tannins from decaying plant matter. Their natural habitat is densely vegetated, providing them with ample hiding spots and a subdued light environment.

Lifespan

The expected lifespan of the Mosquito Rasbora is 4-8 years, depending on the quality of care and the conditions within the aquarium. Proper diet, clean water, and a stable environment can help these fish live to the upper end of this range.

Short Description

Mosquito Rasboras are delicate, petite fish that are best suited for species-specific tanks or peaceful nano-community setups. Their small size makes them less ideal for large community tanks where they may struggle to compete for food. It’s recommended to keep them in groups of at least 8, as they are social creatures that thrive in numbers. These fish are tolerant of a wide range of water parameters but are particularly sensitive to fluctuations, so a fully cycled aquarium is essential before introducing them. A heavily planted tank with dim lighting mimics their natural habitat and helps them feel secure. Since they originate from slow-moving waters, minimal water flow is ideal. High water quality should be maintained through regular water changes. Suitable tank mates include other peaceful, small fish like Tetras or similar-sized cyprinids.

Food and Feeding

Mosquito Rasboras are omnivores that require a balanced diet to thrive. In the wild, they feed on tiny invertebrates, zooplankton, and algae. In the aquarium, a quality micro-pellet or flake food can form the base of their diet, but it should be supplemented with live or frozen foods like Daphnia, baby Brine Shrimp, and micro-worms. These foods replicate their natural diet and promote vibrant coloration and overall health. They will also graze on algae and biofilm that form on plant leaves and decorations, so adding some leaf litter to the tank can provide them with additional foraging opportunities.

Sexing

Male Mosquito Rasboras are generally slimmer, slightly smaller, and display brighter coloration compared to females. The dominant males in the group will exhibit a deeper, more intense red hue, especially during breeding displays. Females tend to have a rounder abdomen, particularly when carrying eggs.

Breeding

Mosquito Rasboras are prolific breeders, often spawning without any special intervention from the aquarist. They are egg scatterers, laying a few eggs each day among plants or other fine-leaved decorations. To maximize fry survival, it is advisable to remove the adults after spawning, as they may consume the eggs if they find them. The eggs typically hatch after 24-36 hours, and the tiny fry should be fed infusoria or commercially available liquid fry food until they are large enough to accept newly hatched Brine Shrimp. Given their frequent spawning, it's important to have extra tanks or containers ready to house the numerous batches of fry. Air-driven sponge filters are ideal for fry tanks as they provide gentle filtration without risking the fry being sucked into the filter. Daily, small water changes will help maintain water quality without stressing the delicate fry.