Rutten's rasbora

Rasbora rutteni

Also known as Rutteni rasbora, Blue cardinal rasbora

FreshwaterFish

Rutten's rasbora (Rasbora rutteni) — The Wet Spot Tropical Fish · Used with permission

Care at a glance

Temperature: 73–81°F (23–27°C)
pH: 5.5–7.0
Adult size: 2.2 in (5.5 cm)
Minimum tank: 20 gal (75 L)
Temperament: Peaceful
Social behavior: Schooling
Swim level: Middle
Difficulty: Medium
Breeding: No record
Rarity: Rare
Origin: Borneo, Indonesia
Family: Danionidae

Overview

Rutten's rasbora is a peaceful, mid-water schooling fish best kept in a group of at least eight, where it settles and shows a soft blue sheen along the side. It suits a calm community of other Bornean or Southeast Asian fish and holds to the middle of the tank. Feed a varied diet of flake, small sinking granules, and small frozen or live foods such as daphnia, cyclops, and brine shrimp. A planted tank of around 75 liters with soft, gently flowing water and open swimming space keeps a group content.

In the wild

It lives in small, clear softwater forest streams in Borneo, over mixed sand and gravel among vegetation, with gentle flow. Match that with a planted tank, sandy substrate, some driftwood, and quiet, well-filtered water. Soft and slightly acidic to neutral is ideal, with the temperature between 23 and 27 C and the pH from 5.5 to 7.0.

Good to know

Rasbora rutteni, family Danionidae, grows to about 5.5 centimeters and is also traded as the blue cardinal rasbora for the bluish stripe along its flank. It is named after Louis Rutten, a Dutch geologist who worked in Borneo. Its aquarium breeding is not documented, though as a rasbora it is expected to be an egg-scattering spawner without parental care.

Did you know

The fish honours a geologist: Louis Rutten surveyed Borneo for an oil company in the early twentieth century, and animals collected on such expeditions often ended up carrying the names of the people who led them.