Slender Betta (Betta bellica)

Betta bellica (Slender Betta or Penang Betta) is a large, elegant wild betta from peat swamps and blackwater streams of Peninsular Malaysia, Sumatra, and southern Thailand. Males are slender with iridescent blue-green scales on a dark body and red-edged fins displaying beautiful colouration in proper blackwater conditions. Despite their size, they are less aggressive than B. splendens and can be kept as a pair in a spacious blackwater aquarium.

Maintain extremely soft, acidic water (pH 4.0–6.5, GH <5) with tannin staining from botanicals, peat, or blackwater extract. Provide a large, well-planted aquarium with floating plants at the surface for the bubble nest. Feed live and frozen carnivore foods: crickets, mealworms, frozen bloodworm, and mysis. Keep as a bonded pair — males are semi-aggressive with each other. Tight-fitting lid essential.