Micro rasbora

Boraras micros

Also known as Micros rasbora, Least rasbora

FreshwaterFish

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: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: Medium
Rarity: Rare
Origin: Known only from a few marshes and floodplain pools in northeastern Thailand.
Family: Cyprinidae

Overview

Keep micro rasboras in a group of at least eight to ten in a mature tank of 30 litres or more, with soft, acidic water at 22 to 26 C and a pH of 5.0 to 6.5. They are sensitive to swings in water quality, so stable, gently filtered blackwater conditions matter. Feed very small foods such as micropellets, crushed flake, baby brine shrimp, and microworm. They are far too small and gentle for anything but other nano fish or dwarf shrimp.

In the wild

Boraras micros lives in shallow, still marshes, rice fields, and floodplain pools in northeastern Thailand, in soft, acidic water thick with plants. It is one of the smallest fish in the hobby, barely over a centimetre long. The body is a pale yellow-green with small dark spots rather than the bright red of its relatives. It suits a quiet, mature nano tank with stable water.

Good to know

Boraras micros is the smallest member of the genus Boraras and one of the smallest known cyprinids, maturing at around 1.5 cm. It was described in 1993 from marshes in the Udon Thani and Nong Khai provinces of Thailand. Its plainer color makes it far less common in shops than the red chili and dwarf rasboras.