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Micro rasbora

Boraras micros

Also known as Micros rasbora

FreshwaterFish

Micro rasbora (Boraras micros)
The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature
72–79°F
22–26°C
pH
5.0–6.5
Adult size
0.6 in
1.5 cm
Minimum tank
8 gal
30 L
Temperament
Peaceful
Social behavior
Shoaling
Swim level
Middle
Difficulty
Medium
Breeding
Medium
Rarity
Rare
Family
Cyprinidae
Origin
Known only from a few marshes and floodplain pools in northeastern Thailand.

Overview

The micro rasbora is one of the smallest fish in the hobby, a peaceful shoaling fish for a quiet nano tank. It is best with a little experience.

Did you know

A full grown micro rasbora is smaller than the fry of many common aquarium fish. That tiny size is part of why it stays a specialist keeper's fish.

Caring for the micro rasbora

Keep micro rasboras in a group of at least eight to ten. A quiet, mature tank of 8 gal (30 L) or more suits them. They are sensitive to swings in water quality, so stable, gently filtered blackwater conditions matter.

Give them soft, acidic water at 72 to 79°F (22 to 26°C) and a pH of 5.0 to 6.5. Feed very small foods such as micropellets, crushed flake, baby brine shrimp and microworm.

Micro rasboras are peaceful but far too small and gentle to share a tank with anything but other nano fish or dwarf shrimp. Breeding them is a moderate challenge.

Good to know

Boraras micros is the smallest member of the genus Boraras and one of the smallest known cyprinids. It was described in 1993 from marshes in the Udon Thani and Nong Khai provinces of Thailand. Its body is a pale yellow-green with small dark spots, rather than the bright red of its relatives. That plainer color makes it far less common in shops than the red chili and dwarf rasboras.

In the wild

The micro rasbora lives in shallow, still marshes, rice fields and floodplain pools in northeastern Thailand. It is known only from a few of these marshes and pools. The water there is soft, acidic and thick with plants.

Weekly picks

Tank mates

The micro rasbora is a peaceful, shoaling species that keeps to the middle. These picks share a community profile with it, are safe together in both directions, and overlap on water type, temperature and pH.

Check the full mix in the stocking calculator

Common questions

What size tank does a micro rasbora need?

A micro rasbora needs at least 8 gal (30 L). It spends most of its time in the middle.

What temperature and pH does a micro rasbora need?

A micro rasbora is comfortable at 72–79°F (22–26°C) with a pH of 5.0–6.5.

What does a micro rasbora eat?

A micro rasbora eats very small foods, such as micropellets, crushed flake, baby brine shrimp and microworm.

How big does a micro rasbora get?

An adult micro rasbora reaches about 0.6 in (1.5 cm).

Does a micro rasbora need a group?

Yes. A micro rasbora is a shoaling species and should be kept in a group, not singly.

Related species