This species is included in the Betta waseri group/complex of closely-related species within the genus, an assemblage which also includes a handful of potentially new species such as B. sp. ‘Medas’ on an unofficial basis. Group members share the following combination of characters: base body colouration clay yellow; opercle scales iridescent gold in mature males of all species except B. tomi; throat with black markings which join with black lower jaw in some species; no chin bar.

This species is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

It can be told apart from other members of the B. pugnax group by the following characters: second postorbital stripe on opercle complete; no transverse bars in caudal-fin; 20-22 predorsal scales; preanal length 50.6-54.8 % SL. Not all authors consider it a member of this group, however, with some placing it in the B. picta complex, e.g., Schindler and Schmidt (2006).

The genus is th…

Prior to official description this species was traded as B. sp. ‘Laut’. It’s included in the Betta unimaculata complex of closely-related species within the genus, , of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in sha…

Known only forest hill streams with flowing, clear water. These are typically shaded from the sun by dense riparian vegetation. The substrate is composed of rocks or gravel, fallen leaves, branches and submerged tree roots, and presumably the fish show a preference for quieter marginal zones as with related congeners.

The type locality was described as a ‘swampy stream’ and sympatric species incl…

It can be told apart from other members of the B. pugnax group by the following characters: chin bar absent; prsence of transverse bars in the dorsal-fin; no transverse bars in caudal-fin; green iridescent scales present on opercle and body; anal fin with iridescent, light blue distal band; a pair black markings below the postorbital stripe on the opercle of females and juveniles; anal-fin rays 25-29 (mode 28); lateral scales 28-30 (mode 29); postdorsal scales 10-11 (mode 12); pelvic-fin length 34.8-50.6% SL; head length 33.4-36.8% SL; inter-orbital width 31.7-37.4% HL.

This species was known as B. sp. ‘Mandor’ or B. sp. ‘ninja’ prior to official description. It belongs to the Betta foerschi group/complex of closely-related species within the genus, of which members share the following set of characters: possession of iridescent blue or green unpaired fins; rays and interradial membranes in unpaired fins not contrasting; dorsal fin with thin, bright white distal band; opercle with two, reddish-yellow, vertical bars.

Members are regarded as being closely-related to bubble-nesting Betta species since they share exhibit certain similarities in morp…

This species is included in the Betta unimaculata complex of closely-related species within the genus, of which members share the following set of characters: body long and slender with depth at dorsal fin origin 18-25 % SL; head large and blunt with width 19-24 % SL; long maxilla and lower lip with distance from tip of lower jaw to posterior end of maxilla 27-54 % HL; caudal-fin rounded in shape, occasionally with elongated median rays; pelvic-fin short and filamentous; dorsal and anal fins relatively pointed.

This species is included in the B. pugnax complex of closely-related species within the genus, an assemblage of which members are notoriously difficult to tell apart from one another, but which can be characterised collectively by the following set of shared characters: relatively large head measuring 28-40% SL; live colouration usually brown with green or blue iridescent spots; male with similarly-coloured scales on opercle, sometimes extending to abdomen; juveniles and females usually brown with two central body stripes and a dark marking on the caudal peduncle; anal-fin in mature specimens pointed and often elongated; caudal-fin lanceolate.

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…