- Source: Spotfin betta
The spotfin betta or Brunei beauty (Betta macrostoma) is a species of labyrinth fish endemic to the island of Borneo. It generally inhabits pools of very slow-moving water along rivers and streams in very shallow waters of 30 cm (12 in) or less. This species grows to a length of 6.7 cm (2.6 in) in the wild, and is occasionally found in the aquarium trade; in captivity this species regularly reaches 4 inches in length.