The Maculata Rasbora (scientific name Boraras maculatus) is one of the smallest freshwater aquarium fish in the world. Aquarists often call it the Dwarf Rasbora because of its tiny size and peaceful behavior. It is very popular in nano aquariums and planted tanks.

Basic Information

• Scientific name: Boraras maculatus

• Common names: Maculata Rasbora, Dwarf Rasbora, Pygmy Rasbora

• Family: Cyprinidae (carp family)

• Origin: Southeast Asia

• Natural habitats: Peat swamps, blackwater streams, slow forest creeks

Countries where it is commonly found:

• Indonesia

• Malaysia

• Southern Thailand

• Singapore

These fish live in soft, acidic, tannin-rich water with lots of plants and leaf litter.

Size and Lifespan

• Adult size: 1.5–2 cm (about 0.6–0.8 inches)

• Lifespan: 3–5 years in a well-maintained aquarium

Because they are extremely small, they are ideal for 5–20 gallon nano tanks.

Appearance

Key features:

• Bright red or orange body

• Three dark spots along the body

• Transparent fins with red tones

• Slim torpedo-shaped body

Males

• Brighter red coloration

• More slender

Females

• Slightly larger

• Rounder belly

Behavior & Temperament

Maculata Rasboras are:

• Very peaceful

• Schooling fish

• Shy but active

They should always be kept in groups.

Recommended school size:

• At least 8–10 fish

• 15+ fish is ideal

Larger groups make them less shy and more colorful.

Ideal Aquarium Setup

Tank Size

• Minimum: 5 gallons

• Ideal: 10–20 gallons

Water Parameters

• Temperature: 22–28°C (72–82°F)

• pH: 4.5–7.0

• Hardness: very soft to soft

Tank Setup

Best environment includes:

• Dense plants

• Floating plants

• Driftwood

• Leaf litter (Indian almond leaves)

• Dim lighting

• Dark substrate

They feel safest in heavily planted aquariums.

Diet

Maculata Rasboras are micro-predators in the wild.

Feed small foods such as:

• Micro pellets

• Crushed flakes

• Baby brine shrimp

• Daphnia

• Cyclops

• Microworms

• Vinegar eels

Because of their tiny mouths, food must be very small.

Tank Mates

Good tank mates include other nano peaceful fish:

• Chili Rasboras

• Phoenix Rasboras

• Ember Tetras

• Pygmy Corydoras

• Otocinclus

• Small shrimp (Cherry shrimp, Amano shrimp)

Avoid:

• Betta (sometimes aggressive)

• Angelfish

• Large tetras

• Barbs

• Any fish that can eat them

Breeding

Breeding is possible but not very common in community tanks.

Conditions needed:

• Soft acidic water

• Heavy plants or moss

• Low light

Spawning process:

1. Males court females among plants.

2. Eggs are scattered in moss.

3. Adults do not guard eggs.

4. Eggs hatch in 24–48 hours.

Fry require:

• Infusoria

• Liquid fry food

• Later baby brine shrimp

Differences From Chili Rasbora

Many people confuse them with Chili Rasbora.

Interesting Facts

• One of the smallest aquarium fish in the world

• Perfect for nano aquascapes

• Looks best in blackwater aquariums

• Very sensitive to poor water quality

• Colors intensify in soft acidic water

✅ Quick summary

• Size: ~2 cm

• Temperament: peaceful schooling fish

• Tank: planted nano tank

• Group size: 10+ recommended

• Difficulty: easy to moderate