Chilli Rasbora Care Guide - Aquarium Setup, Diet & Breeding

The Chilli Rasbora is one of the smallest and most colourful members of the rasbora family. Its slender body is usually a rich ruby-red to orange-red, marked by a darker lateral stripe and subtle black accents. Mature males often develop especially vivid colouration, making a lively group look like a collection of tiny sparks moving through the aquarium.

These fish are peaceful, alert and naturally sociable. In a group, they spend much of their time weaving through vegetation and hovering in the middle and upper areas of the water, with males sometimes displaying to one another by intensifying their colours and briefly sparring without causing serious injury.

In the wild, Chilli Rasboras are associated with shaded waters beneath dense rainforest cover. Fallen leaves, submerged roots and peat-rich substrates release tannins into the water, creating the dark, tea-coloured conditions typical of Bornean blackwater habitats.

Their diminutive size and gentle nature have made them particularly popular among aquarists who enjoy carefully designed nano aquariums. Despite their small stature, they are active and expressive fish, and a well-established shoal displays much more natural behaviour than an isolated pair or a very small group.

Chilli Rasboras come from the island of Borneo, particularly the Indonesian province of South Kalimantan. They inhabit slow-moving blackwater streams, peat swamps and forest pools with soft, acidic, tannin-stained water.

A group should have at least a 30-litre aquarium, with a footprint of around 45 × 30 cm or larger being preferable. Use gentle filtration and create a densely planted layout with fine-leaved plants, mosses, floating cover, driftwood and subdued lighting. A dark sand or fine gravel substrate helps their colours stand out, while leaf litter and botanicals can recreate the sheltered, tannin-rich character of their natural blackwater habitat. Keep the aquarium mature and stable, with plenty of open swimming space among the vegetation.

Up to approximately 2 cm (0.8 inches). Females are usually slightly larger and deeper-bodied than males; males are generally slimmer.

Offer a varied diet of very small foods, such as finely crushed quality flakes, nano pellets, powdered preparations, baby brine shrimp, daphnia and microworms. Their mouths are tiny, so food must be appropriately sized. Regular portions of small live or frozen foods help maintain their colour and condition, while feeding little and often reduces waste.

Chilli Rasboras are best kept with other peaceful, similarly tiny species. Suitable companions include small shrimp, snails, pygmy Corydoras, Otocinclus and other gentle nano rasboras, provided the aquarium offers plenty of cover. Avoid large, boisterous or predatory fish, including angelfish, larger barbs, many gouramis and most cichlids, as they may intimidate or eat these very small rasboras.

Chilli Rasboras are egg-scattering fish that may spawn regularly among fine-leaved plants, mosses or other dense cover. For intentional breeding, use a mature, softly filtered breeding aquarium with slightly acidic, warm water and protect the eggs from the adults. The tiny fry become free-swimming after several days and initially need infusoria or another suitably small first food before progressing to newly hatched baby brine shrimp and fine powdered foods.

Males are typically smaller, slimmer and more intensely red, especially when displaying. Females are slightly larger with a rounder abdomen and often show paler, more orange or pinkish colouration, becoming noticeably fuller when carrying eggs.