TankBud

Dusky betta

Betta fusca

Also known as Brown betta

FreshwaterFish

Care at a glance

Temperature
72–79°F
22–26°C
pH
5.5–7.5
Adult size
2.8 in
7 cm
Minimum tank
21 gal
80 L
Temperament
Mostly peaceful
Social behavior
Social
Own kind
One male per tank
Tankmates
With caution
Swim level
Middle
Difficulty
Medium
Breeding
Medium
Rarity
Very rare
Family
Osphronemidae
Origin
Medan area, North Sumatra

Overview

Adults are large and boisterous for a wild betta and can rough up small fish, so keep one male with one or two females in a tank of 80 liters or more, with tank mates of similar size or none. It uses the middle of the water. Keep it at 22 to 26 C and pH 5.5 to 7.5, and it is not fussy about hardness. It takes prepared foods readily alongside frozen bloodworm, brine shrimp, and insects. The male broods for about two weeks before releasing the fry.

In the wild

The dusky betta is a Sumatran fish, but the only confirmed specimens were collected near Medan in the north of the island in 1908, and attempts to find it there again have failed. Fish sold under the name come from other parts of Sumatra, such as Pekanbaru, and were taken from pools and flowing forest streams. Set up a roomy, dim tank with sand, driftwood, leaf litter, dense planting, and gentle filtration, and keep the lid tight.

Good to know

Betta fusca is a mouthbrooder in the Betta pugnax group of the family Osphronemidae, described by Regan in 1910 and named for its dusky look, with a dark band through the eye and dark edged scales. Tan and Ng redescribed it in 2005 from just two old specimens, the lectotype 59.7 mm standard length, and concluded the species is known only from the type series. FishBase quotes 8.2 cm total length, and aquarium fish sold as fusca reach 10 cm or more, so the size here is a working figure. The IUCN lists it as Critically Endangered.

Did you know

The real Betta fusca may not exist in the hobby at all. Tan and Ng could only find Regan's two 1908 specimens from Medan, and the IBC species program notes that the fish imported as fusca are most likely Betta raja or another member of the pugnax group.

Common questions

What size tank does a Dusky betta need?

A Dusky betta needs at least 21 gal (80 L). It spends most of its time in the middle.

What temperature and pH does a Dusky betta need?

A Dusky betta is comfortable at 72–79°F (22–26°C) with a pH of 5.5–7.5.

How big does a Dusky betta get?

An adult Dusky betta reaches about 2.8 in (7 cm).

Related species