Brilliant rasbora

Rasbora einthovenii

FreshwaterFish

Care at a glance

Temperature: 72–82°F (22–28°C)
pH: 6.0–7.5
Adult size: 3.5 in (9 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Easy
Breeding: No record
Rarity: Very rare
Origin: Malaysia, Thailand, Sumatra
Family: Cyprinidae

Overview

Brilliant rasboras are peaceful, sociable shoaling fish that should be kept in a group of at least eight, as numbers give them the confidence to come out and swim in the open. They occupy the middle water and move as a loose, coordinated group along the length of the tank. Their calm nature makes them ideal for a quiet community with other small, gentle species, and they should not be housed with boisterous or fin nipping tankmates. Feed small foods they can take mid water, such as fine flake, micro pellets, and frozen or live daphnia and cyclops. A tank around 75 liters or larger suits a proper shoal.

In the wild

This rasbora lives in the peat stained blackwater streams and forest pools of Malaysia, Thailand, and Sumatra, where the water is soft, acidic, and dimly lit beneath overhanging vegetation. It shows best in warm water of about 22–28 C and a pH toward the lower end of 6.0–7.5. Recreate its home with a dark substrate, plenty of driftwood and leaf litter, and tannin stained water from botanicals such as dried leaves or alder cones. Gentle filtration, subdued lighting, and patches of planting help it feel secure and bring out its colors.

Good to know

Rasbora einthovenii is a slender member of the family Cyprinidae that reaches around 9 cm. Its defining feature is a bold blue black stripe that runs from the snout straight through the body and onto the central rays of the tail fin, edged above by a fine gold line that can gleam in good light. Like other rasboras it is an egg scattering, non guarding spawner that deposits eggs among fine leaved plants. There is no well documented account of it being bred at home, and most fish offered for sale are wild caught or farmed abroad.

Did you know

The name brilliant rasbora comes from the way the dark lateral stripe catches the light, throwing a blue to green metallic sheen along an otherwise plain silver body. In the tea colored blackwater it comes from, that flash of color stands out clearly against the dark background.