Maximum size : 10 cm

Clown Rasbora - Rasbora kalochroma : Complete Fish Profile & Care Guide

Table of contents


The Clown Rasbora (Rasbora kalochroma) is a charming and peaceful schooling fish that should be kept in groups of 8 to 10 specimens to foster their natural behaviour and reduce stress levels. By doing so, their captivating colours and unique patterning will be on full display, and the males will engage in a delightful display of competition for female attention while maintaining a harmonious environment. Due to their delicate nature, these Rasboras are not recommended for beginner aquarists.

While they are suitable for community aquariums, it is essential to keep tankmates that share a similar temperament and size, as this species can be quite delicate. A selection of appropriate companions may comprise Loaches, diminutive and tranquil barb species, as well as Chocolate Gouramis. Expanding the scope, several medium-sized South American Tetras and Corydoras Catfish represent commendable choices for harmonious tank cohabitation.

The Clown Rasbora finds its optimal habitat in spacious soft water aquariums. To best emulate their natural surroundings, the aquarium should exhibit a mature state characterized by an abundance of dark decor, prominently featuring intertwined driftwood formations and robust vegetation. While a subdued luminance is preferred, a marginally brighter illumination is acceptable under the condition that the presence of floating plants or larger, broad-leaved flora serves to diffuse the light, engendering an array of shaded areas.

In light of their natural habitat, which encompasses highly acidic, tannin-infused softwater forest swamps, the incorporation of peat filtration within the aquarium is recommended to replicate the desired blackwater conditions. Augmenting this effect, the presence of driftwood assumes significance alongside the beneficial addition of dried Indian almond leaves. The infusion of tannin-stained water serves a dual purpose, enhancing the display of the fish's striking red hues while simulating their natural environment.

The Clown Rasbora's striking appearance is characterised by its pinkish-red body colouration and two large dark blotches, one behind the gill cover and the other in the midsection of the flank between the anal and dorsal fins. Some variations of this species display spot-like markings that connect the two dark blotches, adding a unique touch of beauty to any aquarium.

Clown Rasbora Photos

Sexual Dimorphism

Distinguishing male and female Clown Rasboras is a straightforward process. Females are generally larger and possess a more robust build, while males tend to be slimmer and exhibit more vibrant colours compared to their female counterparts.

Quick Facts

Scientific NameRasbora kalochroma
Year Described1851
Other NamesBig Spot Rasbora
Max Size10 cm
Aquarium LevelAll Levels
DifficultyIntermediate - Advanced
Best kept asGroups 8+
Diet & FeedingOmnivore
LifespanUp to 5 Years

Water Parameters

Water TypeFreshwater
pH 5.0 - 7.5
GH 2 - 10
Ideal Temperature
73 - 82
22 - 27

Natural Habitat

Endemic to the Malay Peninsula, the Greater Sunda Islands in Borneo, and Sumatra in Indonesia, the Clown Rasbora hails from Southeast Asia. Inhabiting soft, acidic rivers and forest streams associated with peat swamps, these fish thrive in waters that are heavily stained with tannins due to decaying plant matter. Their natural substrate consists of scattered twigs, fallen leaves, and branches, often shaded by the lush forest canopy overhead. 


The Clown Rasbora is an egg-scattering, continuous spawning species that exhibits no parental care. In a densely planted community tank with a plentiful food supply, small numbers of fry may successfully emerge. However, to maximise yield, a separate breeding tank is necessary. This tank should be shallow, dimly lit, and feature mesh, marbles, or pebbles at the bottom to allow non-adhesive eggs to fall through or delicate-leaved plants to protect eggs and fry from adult predation.

The water should be slightly acidic and filtered with a mature air-driven sponge filter, with the temperature slightly elevated compared to their standard requirements. Breeding Clown Rasboras in pairs is recommended, with spawning induced through small, cold-water additions to simulate rainfall and the conditioning of pairs with live foods.

Following spawning, adults should be removed to prevent predation on the eggs and fry. The incubation period varies depending on temperature, with eggs typically hatching within 24-48 hours. Newly hatched fry should be initially fed infusoria or commercial liquid fry food before gradually accepting baby brine shrimp and similar offerings as they grow.

Diet & feeding

The Clown Rasbora is a low-maintenance species in the home aquarium, readily accepting a range of food types. To promote optimal physical condition and vibrancy of colouration, a diverse diet consisting of daily portions of frozen and live foods such as daphnia, bloodworms, and artemia, complemented by high-quality dried flakes, granules, and freeze-dried offerings, should be provided.

Other Rasboras of interest