Known only from northwestern Sumatra, Indonesia with definitive records existing from the Singkil area in Aceh province and around Sibolga in North Sumatra (Sumatera Utara) province.
Type locality is given by Perugia as ‘Lago Toba, Siboga’, with the latter an alternative or misspelling of ‘Sibolga’, although it’s not thought to inhabit the lake itself which lies at an altitude of around 900 m AMSL.
Other former localities for B. rubra are currently considered to refer to the closely-related B. dennisyongi and it’s unclear if the two occur together naturally in some locations due to human interference (Tan, 2013).
All rivers in northwestern Sumatra drain into the Indian Ocean and the region is hydrogeographically isolated from the remainder of the island by the Barisan mountain range, resulting in it being considered a distinct ichthyofaunal province due to the high proportion of endemic species occurring there.
Much of this area has been beset by violence for many years due to an ongoing struggle between the Gerakan Aceh Merdeka (better known as the Free Sumatra Movement in the West) and the Indonesian Government resulting in B. rubra being known only from the type specimens for around 100 years.
Following a peace agreement in 2005 the area seems to have become safer as the species began to appear in the aquarium hobby during early 2007.
Most recently collected from a highly-disturbed tract of former peat swamp forest which in 2009 had been cleared for possible planting of oil palms with much of the water drained via man-made ditches.
The fish were collected from a stagnant blackwater pool with a pH of 5.5 and no other fish species were present, while surrounding pools and a nearby river were not found to contain any specimens.
Temperature: 22 – 27 °C
pH: 5.0 – 6.5
Hardness: 18 – 90 ppm
© Haji Badaruddin