Chili Rasbora

Overview

The Chili Rasbora is one of the smallest fish in the aquarium hobby, barely bigger than half an inch long, yet it packs a punch of color. The males glow a bright, glowing red like a tiny chili pepper, with a dark red stripe running down the side. It comes from the blackwater swamps and peat forests of Borneo in Southeast Asia, where the water is soft, acidic, and stained brown from fallen leaves.

Because they are so tiny and shy, Chili Rasboras are best kept in a calm, planted nano tank in a large group, where their red bodies look like sparks drifting through the plants. They are peaceful and gentle, but their small size means they need special care with water and tankmates. For patient keepers, a shoal of glowing chilis is one of the prettiest sights in a small aquarium.

Water and tank

Chili Rasboras come from soft, acidic blackwater, so they do best in warm water that is soft and slightly acidic. A group can live in a tank as small as 10 gallons, since they are so tiny. They are sensitive to poor water, so the tank should be fully cycled and mature before they move in. Gentle filtration and steady conditions are the keys to keeping them healthy.

Aquascape and setup

A heavily planted blackwater tank is their dream home. Dried leaves and driftwood stain the water a soft tea color and make the fish feel safe, while lots of plants and mosses give them cover. A dark substrate and background make their red bodies glow even brighter. Keep the filter flow gentle, because these tiny fish are weak swimmers and do not like being pushed around by strong currents.

Diet and feeding

Chili Rasboras have very small mouths, so they need very small food. In the wild they hunt tiny creatures, so offer them micro foods like baby brine shrimp, daphnia, cyclops, and finely crushed flakes or micro pellets. Live and frozen foods bring out their brightest red color. Feed small amounts a couple of times a day and make sure the food is small enough for them to swallow.

Tankmates and temperament

These are among the tiniest fish you can keep, so they need equally tiny, gentle tankmates. Good choices include celestial pearl danios, small shrimp, and snails. Avoid anything big enough to eat them or bold enough to bully them or steal their food. Kept in a large group of ten or more, they feel secure, and the males color up and playfully display to one another.

Breeding and eggs

Chili Rasboras will quietly breed in a mature, planted tank. They are egg scatterers that lay their eggs among mosses and fine plants and give them no care afterward. Because the parents and other fish may eat the eggs and fry, a densely planted tank helps a few babies survive on their own. The tiny fry are hard to spot and need very small foods like infusoria to grow.

Fun facts

• The Chili Rasbora is one of the smallest aquarium fish, often under three quarters of an inch long.
• Males glow a bright, fiery red, which is how the fish got its spicy 'chili' name.
• They come from the soft, tea-colored blackwater swamps of Borneo.
• A big shoal drifting through plants looks like a scatter of tiny glowing embers.
• Despite their tiny size, they can live many years in a healthy, stable tank.

Frequently asked questions