Clown rasboras live in forest streams which are heavily stained with tannins. As a result direct sunlight doesn't penetrate in to their environment and so the species does best in a low light set up. Bogwood, rockwork, twigs and dried leaves make ideal naturalistic decor for their aquarium. Clown rasboras are quite large and they are extremely active swimmers, as such they require a relatively large aquarium for their size. 250litres (typically a 48" x 18" x 18" aquarium should be considered the minimum size for a group of these fish. It is essential that these fish are kept in soft acidic water if they are to thrive. Groups of clown rasboras should have a ratio of one male to two females if possible and ideally at least twelve individuals.
In the wild their diet consists of mostly small inverts such as worms, crustaceans and molluscs. In captivity they are relatively unfussy and will accept a range of prepared food such as flake, suitably sized pellets but these should not be used alone. Fresh meaty food such as live or frozen bloodworms, daphnia, cyclops, brine shrimps, glass worms all should be a part of their regular diet in order to keep the fish in top condition.
Clown Rasboras are reliably peaceful and make excellent community fishes with other peaceful fish of a similar size.
Females are slightly larger and more heavily built, males exhibit the more vibrant colours.
With good care fry may appear on a regular basis in the aquarium but the fry are unlikely to survive. In order to raise a full brood a separate breeding aquarium will have to be used.
Use a long shallow tank with a temp of 27 to 28C filled with very soft acidic water and filtered with a mature air driven sponge filter. No lighting should be used and the tank should ideally be in shadow.
The floor area should be covered with small pebbles or marbles so that the non-adhesive eggs can fall through and out of reach of the adults. On top of this use bunches of fine leaved plants which the fish will use as a spawning mop.
Place a well conditioned pair in the tank and leave then to settle for a while, then make a small water change using slightly cooler water, this will often trigger spawning.
Remove the parents after spawning and the fry will hatch after 24 to 36 hours depending on the temperature and they will be free swimming after a further 24 to 48 hours. Once free swimming the fry can be fed using a commercial liquid fry food, infusoria or newly hatched brine shrimps.
Wild populations of Rasbora kalochroma have not been evaluated but the species is not thought to be vulnerable in the wild.
A word of caution, keep clown rasboras well covered as they are good jumpers and sooner or later fish from an uncovered aquarium will be lost.