Brunei Beauty

Geographic Origin and Biotope: Endemic to Brunei (north-western Borneo). Inhabits pools and slow clear water flows in forest streams. Usually found under waterfalls where the water is highly oxygenated and surprisingly cool for the area.

Taxonomy and Morphology: Brunei Beauty (Betta macrostoma). The "Holy Grail" of wild Betta lovers. It is one of the largest Bettas; "macrostoma" means large mouth, necessary for oral incubation. Massive body, large scales and straight dorsal profile.

Social Behavior: Extremely aggressive towards conspecifics. Can only be kept singly or in a bonded pair. Even females can be brutal with each other or with the male. A continuous visual escape route must be provided in the tank.

Coloration and Sexual Dimorphism: The male has an inimitable livery: coal-black head (in breeding dress), bright rust-red flanks and a dorsal fin decorated with a showy ocellus (black spot) bordered in red and white. Brown females with two blackish longitudinal stripes.

Aquarium Setup: Dedicated 80-100 cm (32-40 inches) tank. Clear water, smooth rocks and woods. FUNDAMENTAL an absolutely hermetic cover (they jump through millimetric cracks) and strong aeration with moving water, unlike swamp Bettas.

Diet and Feeding: Large carnivorous predator. In nature it eats insects, small fish and amphibians. In the aquarium it requires an abundant mix of live and frozen food (bloodworms, mysis, chopped earthworms). Prone to obesity if overfed with industrial pellets.

Water Quality: Requires very clean and cooler waters than the typical Betta (22-26°C / 71-79°F). Temperatures constantly above 27°C (81°F) weaken the immune system leading them to death by parasitosis in a few months. Nitrates close to zero.

Compatibility and Tankmates: To be strictly kept in a tank dedicated to the single pair. Their size and aggressiveness make them a danger to small fish, and they get fatally stressed in the presence of territorial Cichlids or fast fish.

Aquarium Reproduction: Mouthbrooder. Difficult to achieve. Mating is very violent. The male holds the eggs for 18-35 days! Any minimum disturbance (a finger on the glass, a water change) will lead him to instantly devour the eggs.

Risks and Diseases: Very expensive and delicate. Suffers dramatically from drops in water quality and summer temperature peaks. Protected species by the Sultan of Brunei, export of wild specimens is illegal; legal specimens come from captive breeding.