Kalu

This species is also traded/referred to by the vernacular name 'Ceylon fighting fish'. It differs from its only congener, B. hasselti, by its overall reddish (vs. brownish-grey) body colouration, and absence (vs. presence) of a mosaic-like patterning in the unpaired fins. At least three putative phenotypes have been recorded. The nominative, and commonest, mostly inhabits clear streams in rainier zones...

Endemic to Sri Lanka with type locality 'shaded pools of mountain streams at Akuressa, Southern Province, Sri Lanka, elevation 500 meters'. It's known from at least five localities, all of which are located in restricted to Sri Lanka's 'wet zone' in the southwest of the island, with records exis...

This species is also referred to as 'Kretser's paradisefish' and 'spotted gourami'. There exist three colour forms, two of which exhibit a greater degree of reddish or violet pigmentation in the fins, respectively. The third is more bluish and was described as M. kretseri minor by Deraniyagala (1958).

This species was considered a colour form of the related Pethia cumingii prior to its description. It can be told apart from P. cumingii by the following combination of characters: maximum standard length 33.6 mm (vs. 41.2 mm); smaller eye diameter (9.8-10.5, vs. 10.8-12.1 % SL); 11+13 (vs. 11+15) vertebrae; cleithrum with a single spine (vs. smooth); proximal arm of fifth ceratobranchial with an oval...

This species is most easily told apart from its only congener P. dayi by lacking (vs. possessing) two dark, irregular lateral stripes on the head and body, and a shorter caudal-fin in males. The results of phylogenetic analyses by Rüber et al. (2006) suggest that Pseudosphromenus is most closely-related to Malpulutta in an evolutionary sense.

These are still regarded as valid by some authorities although it's widely accepted that they represent variants of R. vaterifloris due to a lack of type material hindering conclusive study. Rasboroides nigromarginata (Meinken, 1956) has also been used to refer to a reddish form in which males differ from other populations in possessing dark fin margins, but the name is currently considered synonymous with R. vaterifloris by most sources despite the fish being rediscovered in 2010.

Prior to its description P. kamalika was referred to as P. amphibius, a putatively valid species probably restricted to western India. It differs from all congeners in the following combination of characters: 4½/1/2½ scales in a transverse line between the mid-dorsal...