Betta pugnax

Betta pugnax is one of the larger wild mouthbrooding bettas, reaching up to 10 cm in length. It originates from forest streams, ditches, and slow-moving waters of Peninsular Malaysia and Singapore. Males display an olive-brown base colouration with vivid metallic blue-green scale iridescence and red-edged fins that intensify during courtship displays.

As a paternal mouthbrooder, spawning follows an elaborate embrace sequence. The male collects and incubates the eggs in his buccal cavity for approximately two weeks before releasing free-swimming fry. The species is relatively robust compared to other wild bettas and tolerates a broader pH range, making it more accessible to intermediate keepers.

A spacious, well-planted tank of at least 60 litres is recommended. The tank should have tight-fitting lids, as B. pugnax is an accomplished jumper. It can be kept as a pair or in a harem of one male with two or three females in larger setups.

Water: 23–28°C, pH 5.0–7.0, soft to medium (GH 2–10) — prefers slightly acidic conditions. Tank: 60 L minimum, heavily planted with ample hiding spots and a tight-fitting lid. Feeding: accepts live and frozen foods readily; can be trained onto quality floating pellets. Breeding: paternal mouthbrooder; male holds fry ~14 days; best moved to brooding tank. Compatibility: keep as a pair or species group; generally ignores other peaceful, dissimilar fish.