Nilwala

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...

This species is diagnosable from other members of the genus primarily by its unique colour pattern which consists of 7-11 dark blue, irregularly-shaped, parallel vertical bars on the anterior portion of each flank plus a short horizontal stripe on the caudal peduncle which extends into the central caudal fin rays. Phylogenetic analyses suggest it's most closely-related to Indian Devario spp. plus D. xyrops from the western slope of the Rakhine Yoma mountains in Myanmar (Fang et al., 2009; Fang and Kullander, 2009).

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).

Little sun is able to penetrate the forest floor so aquatic habitats are shaded and water temperature may be relatively cool, while conductivity and hardness are generally low and pH slightly acid. Macrophytes are uncommon though there may be dense, marginal vegetation, sometimes overhanging the full width of the stream, the roots of which may penetrate the banks underwater. Typical substrates are sandy but covered by a layer of leaf litter with fallen twigs and branches.

Generally very peaceful making it an ideal resident of the well-researched community tank. As it places no special demands in terms of water chemistry it can be combined with many of the most popular fish in the hobby including other small cyprinids as well as tetras, livebearers, rainbowfishes, anabantoids, catfishes and loaches. It's a schooling species by nature, and at least 6-10 specimens should be purchased. Maintaining it in such...

As of 2006 only 4.6% of the old forest was left with the remainder existing only in small, highly-fragmented patches, most covering areas less than 10 km², of which some are now officially-protected reserves. Kottawa Forest is one of these and comprises just 15-20 hectares of wet, evergreen jungle, though the combined Kottawa-Kombala forest covers around 1600 ha. A number of minor, pristine streams...

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.

This species is euryhaline and mostly inhabits brackish estuaries, coastal lagoons and the lower reaches of rivers. It also occurs in freshwater habitats, however, including a number of inland lakes in Sri Lanka although it appears to have been introduced intentionally.