Two-spot Rasbora

Geographical Origin and Habitat: Common in the vast river networks of Malaysia and Indonesia. Typically inhabits fast to moderately flowing forest rivers, populating both clearwaters and tannin-stained blackwaters. Avoids turbid or stagnant anoxic zones.

Taxonomy and Morphology: Cyprinidae. Another colossus of the Rasbora genus. Easily reaches 15-16 cm (6-6.5 inches) in length as mature adults. It has a very thick and muscular torpedo-shaped body, with a slightly upturned jaw.

Social Behavior: Extremely peaceful, but impressive in size and activity. It spends every moment of its life swimming tirelessly in the mid-water column. It MUST be kept in schools of at least 6 specimens, where it will develop spectacular swimming hierarchies.

Coloration and Sexual Dimorphism: The body shines with massive metallic silver, often with coppery or yellow-green hues on the back. The unmistakable hallmark are the two large, square 'ink blots': one exactly in the center of the flank (above the pelvic fins) and the other, smaller one on the caudal peduncle. Breeding males display dark red-edged caudal fins and are more streamlined.

Aquarium Setup: Demands almost public-aquarium dimensions: absolute minimum 150 cm (60 inches) long to house an adult school without the fish stressing out by hitting the glass. An Asian river layout (round river stones, driftwood, dense background Vallisneria) and generous powerheads will make them thrive. Secure lid is mandatory.

Diet and Feeding: Voracious omnivores. They burn massive amounts of calories due to their constant swimming. They will eagerly attack large commercial foods (floating pellets), large freeze-dried insects (crickets, silkworms), jumbo brine shrimp, and bloodworms. They will largely ignore food on the bottom.

Water Quality: An armored species. Very tolerant of parameters: accepts pH between 5.0 and 7.5, and moderate hardness (GH 2-12). The only real necessity is that the water be hyper-oxygenated and clean of nitrates (frequent 30-40% weekly water changes).

Compatibility and Cohabitation: Ideal companion (dither fish) for large Cichlids and massive Asian fish. Never pair with slow-moving fish (e.g. Angelfish) which would be terrified by them, or with tiny fish and fry which they will mistake for live food.

Aquarium Breeding: Difficult in the home aquarium solely due to space constraints. They scatter enormous amounts of adhesive eggs among leaves, showing no parental care and eventually eating them.

Risks and Diseases: They will stunt or develop severe spinal deformities if grown in 80-100 cm (3-foot) tanks. They must be able to launch into long, straight sprints without braking sharply.