The type series was purchased from a market in Jambi province, eastern Sumatra, Indonesia and this species is also known from neighbouring Riau province plus the island province of Bangka. On Sumatra it may be restricted to the Indragiri and Batang Hari river systems.

Inhabits peat swamp forests and associated black water streams in which the water is typically stained brown with humic acids and other chemicals released by decaying organic material. The dissolved mineral content is generally negligible and the pH can be as…

This species is the only member of the B. edithae group within the genus, and separated from all other Betta spp. by the fact that the branchiostegal membrane and posterior portion of the opercle are opaque or translucent.

The original diagnosis by Vierke also states that it has relatively small eyes and short fins with a typical pattern of partial barring.

Patterning is highly variable depending both within and between populations and the species may comprise an assemblage containing a number of taxa (Kottelat and Lim, 1993; Tan and Kottelat, 2009). For example, those from Singapore and Johor possessing intricate mottling on the dorsal surface while individuals from Terengganu have a series of saddle-like markings either alternating or connecting with the midlateral markings.

The type locality is a stream in a forest swamp with dense growth of Barclaya motleyi at intervals, part of which had been turned over to cultivation of rubber trees in 1997. The water depth varied between 5-80 cm, pH was 5.8 and syntopic species included ‘Puntius‘ banksi, Rasbora einthoveni, Trigonopoma pauciperforatum, Hemirhamphodon pogonognathus, Betta pugnax, Sphaerichthys osphromenoides, Trichogaster trichopterus, Channa gachua and C. lucius.

B. chloropharynx 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. The easiest way to distinguish these is by examining the throat markings which vary according to species.

In this case the lighter of these form a shape that roughly resembles a horizontal figure of ei…

This species is very rare in the trade and is normally imported only as bycatch among shipments of other fishes.

It can be told apart from its well-known congener B. dorsiocellata by a combination of characters as follows: lateral line complete (25-30 pored scales vs. 4-9); more scales in the lateral row (29-32 vs. 25-27); larger adult siz…