Betta mahachaiensis

Betta mahachaiensis is a wild bubblenesting betta found in coastal areas of Samut Sakhon Province, near Bangkok, Thailand. It is uniquely adapted to brackish water environments in Nipa palm swamps and coastal ditches, a habitat type unlike the soft blackwater preferred by most wild Betta species. Males display superb metallic green and blue iridescence.

In the aquarium, B. mahachaiensis tolerates and even benefits from a small amount of aquarium salt (1–2 g/L). It is otherwise maintained similarly to B. splendens. The species is a paternal bubblenester and males are aggressive toward each other. Their striking colouration rivals many domesticated varieties.

This species is considered Near Threatened due to rapid coastal development around Bangkok. Aquarium-raised specimens are available and their maintenance in captivity contributes to conservation awareness. Breeding is straightforward for anyone experienced with common bettas.

Water: 23–29°C, pH 6.5–8.0, soft to medium hardness; optional 1–2 g/L marine salt benefits this brackish species. Tank: 40 L minimum; floating plants for nest-building; tight-fitting lid. Feeding: betta pellets, bloodworm, daphnia, and brine shrimp — same diet as common betta. Breeding: prolific bubblenester; male guards nest vigorously; remove female after spawning. Compatibility: males must be kept alone; peaceful toward dissimilar community fish.