Type locality is given only as ‘Sarawak state, Borneo, East Malaysia’, with the material deriving from Sibu Division in western Sarawak.

It’s since been recorded at other localities within Sarawak, to which it appears endemic, but it remains unclear whether all represent a single species or not with those from the area around Lundu in northwestern Kuching Division in par…

The genus Betta is the most speciose within the family Osphronemidae with almost 70 recognised members and looks set to grow further with new ones continuing to be described on a regular basis since the turn of the century. Member species have successfully adapted to inhabit a variety of ecological niches from stagnant ditches to flowing hill streams including some extreme environments such as highly acidic peat swamp forests.

Like others in the suborder Anabantoidei this species possesses an accessory breathing organ known as the labyrinth. So-called due to its maze-like structure this organ allows the fish to breathe atmospheric air to a certain extent. Comprising paired suprabranchial organs formed via expansion of the epibranchial (upper) section of the first gill arch and housed in a chamber above the gills, it contains…

An ideal species for the newcomer to 'oddballs'. It is exceptionally hardy, long-lived (it can survive for over 15 years when cared for properly) and exhibits some interesting behaviour. It appears to have evolved convergently with leaf fish of the genera Polycentrus and Monocirrhus (they're not closely related). All these species mimic leaves and other aquatic debris to assist them in hunting their prey. If you add live food to its tank, you will see the typical stalking behaviou…

This species isn't especially popular in the aquarium trade but is undoubtedly interesting despite its lack of colour. In addition to its survival ability in the absence of water it's also capable of producing audible sounds though the purpose of these has not been fully-studied. Naturally-occurring xanthic and albino forms have also been recorded.

There is considerable confusion as to the taxonomic status of the two species currently occupying this genus, with ichthyologists widely…

This species lends it name to the B. bellica group/complex of closely-related species within the genus, an assemblage of which members share the following set of characters: long and slender body with dorsal and ventral margins almost parallel; body depth 23-28 % SL; 30-33 anal-fin rays; 11-13 dorsal-fin rays; 32-34 total vertebrae; body dark brown in colour with iridescent green markings on each individual scale.