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  or less. This species grows to a length of  in the wild, and is occasionally found in the aquarium trade; in captivity this species regularly reaches 4 inches in length. References

Fauna of Brunei
Betta
Taxa named by Charles Tate Regan
Fish described in 1910
Taxonomy articles created by Polbot
Freshwater fish of Borneo