Red-tailed rasbora

Rasbora borapetensis

FreshwaterFish

Care at a glance

Temperature: 72–79°F (22–26°C)
pH: 6.0–7.5
Adult size: 2.4 in (6 cm)
Minimum tank: 18 gal (70 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Beginner
Breeding: Medium
Rarity: Rare
Origin: Thailand, Laos, Cambodia, Vietnam
Family: Cyprinidae

Overview

These are peaceful, beginner-friendly schooling fish that need a group of at least six to feel secure and stay active. They swim in the middle and upper water and pair well with other small calm community fish in a planted tank. A 70 liter tank suits a school comfortably. Feed quality flake, micro pellets, and the occasional frozen or live food like daphnia to keep their color up.

In the wild

Red-tailed rasboras come from Southeast Asia across Thailand, Laos, Cambodia, and Vietnam, living in clear, slow streams, ponds, and rivers with thick plants and a soft sand or mud bottom. The water is neutral to slightly acidic and often shaded by overhanging growth. A planted tank with open swimming room and some shade matches their home. Keep the pH from 6 to 7.5 and temps in the low to mid 20s C.

Good to know

This is a small carp relative in the family Cyprinidae, reaching about 6 cm, with a silvery body, a dark stripe along the side, and a red base to the tail. They are egg scatterers with no parental care. The IUCN lists them as Least Concern, with stable wild populations across a wide range.

Did you know

The red tail patch is easy to miss in a quiet fish but flares up when a school is settled and well fed, and it shows most against a dark substrate and planted background. In a bare bright tank the same fish can look washed out, which is why so many people underrate them at the shop.