''Betta raja'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of betta

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the island of

Sumatra Sumatra is one of the Sunda Islands of western Indonesia. It is the largest island that is fully within Indonesian territory, as well as the sixth-largest island in the world at 473,481 km2 (182,812 mi.2), not including adjacent i ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

. It is an inhabitant of swamps in lowland forests. This species grows to a length of SL. It is used as bait by local fishermen and has also been found in the aquarium trade. Despite its scientific epithet ''"raja"'' meaning "Prince" or "king", this species is not identical to the aquarium breed - the King betta. The derivation of the King betta is not fully known and may or may not involve crossbreeding with ''B. raja''.Juniper Russo (2009):
"King Betta" Variety Sold at Petco

References

raja ''Raja'' (; from , IAST ') is a royal title used for South Asian monarchs. The title is equivalent to king or princely ruler in South Asia and Southeast Asia. The title has a long history in South Asia and Southeast Asia, being attested f ...

Taxa named by Heok Hui Tan Taxa named by Peter Kee Lin Ng Fish described in 2005 {{Rayfinned-fish-stub