Brilliant Rasbora

Geographic Origin and Biotope: Widely distributed in the Malay Peninsula and Borneo. Lives exclusively in lowland forest peat swamps and streams cutting through dense jungles. In these habitats, light barely penetrates, and the water is coffee-colored, mineral-poor, and saturated with tannins.

Taxonomy and Morphology: Cyprinidae. A classic surface 'torpedo' of the Rasbora genus, but of medium-large size (easily reaching 8.5-9 cm / 3.5 inches). Possesses a prominent lower jaw, perfect for swallowing insects fallen into the water.

Social Behavior: Extremely gregarious and very peaceful. Incessantly patrols the upper two-thirds of the aquarium in tight schools (minimum 8 specimens). Their bulk and swimming speed may intimidate slow or shy fish, but they NEVER show interspecific aggression.

Coloration and Sexual Dimorphism: The back is bronze/olive, while the flanks emit a faint silvery/pink (periwinkle) glow under the right lighting. An unbroken, thick, unmistakable black band runs from the tip of the snout, through the eye, straight to the base of the tail. Females are noticeably plumper and deeper-bodied; males are streamlined torpedoes with slightly more intense colors.

Tank Setup: Requires long swimming spaces: minimum 100 cm (40 inch) tank. A dark layout is ideal: fine inert sand, intricate Manila driftwood, Indian almond leaves (Catappa), or alder cones on the bottom to tint the water amber. Light must be dim or heavily shielded by floating plants (Water Lettuce, Salvinia). A lid is mandatory against jumps.

Feeding and Diet: Micro-predators/Insectivores. Easily accept good quality dry food, but prefer foods that float or sink slowly. They go crazy for live insects (tiny crickets, fruit flies) and frozen bloodworms.

Water Quality: Highly resistant if the water is acidic. They despise hard, alkaline tap water: require pH between 5.0 and 7.0, low GH (1-12), and a temperature of 22-26°C (72-79°F). Excellent for those using RO water remineralized with salts.

Compatibility and Cohabitation: Excellent with medium-sized peaceful Asian fish: Clown Loaches, Kuhli Loaches, large Corydoras, and similarly sized Gouramis (Pearl Gouramis). Absolutely unsuitable for housing with nano-fish (Boraras, small Cherry Shrimp) which would inevitably be swallowed by mistake.

Aquarium Reproduction: Egg-scatterers. In a dedicated, dimly lit tank with dense bushes of fine-leaved plants (Java Moss), they will spawn hundreds of eggs at dawn. Unfortunately, they will eat them instantly: breeding must be planned by removing the parents the same morning.

Risks and Diseases: 1. Lethal organic wasting due to hard, calcareous waters. 2. Severe trauma from impacts or jumping if the aquarium is too short or lacks hiding places.