This species is extremely widespread and has been recorded from Pakistan, Nepal, most of India, Bangladesh, Myanmar and southern China.

Type locality is ‘Bengal and western provinces, India’.

Despite its unsuitability for the majority of home aquaria, this species is available in the aquarium trade on an irregular basis, and has also been marketed as ‘violet-gilled shark’, ‘red-gilled violet shark’ and ‘blushing violet shark’.

It appears likely that L. boga as currently recognised represents a complex of closely-related species.

This species can be identified by colour pattern comprising a brownish dorsal surface, yellowish flanks and abdomen, and a black to bluish lateral stripe extending from the eye to the caudal-fin base.

The monotypic genus Incisilabeo is separated from the closely-related taxon Bangana by presence of a unique and conspicuous transverse notch across the top of the head, comparable in position to the ethmoid furrow in Bangana species. This notch approaches the eye, and the top of the head bulges forward, with the nostrils located partially beneath this projection and immediately anterior to the eyes. Tubercles cover the upper portion of the rostral fold, lower part of the notch, and upper surface of the forehead projection…

H. wetmorei is distinguished from congeners by the following combination of characters: upper body reddish brown; robust body, not compressed; usually 4½ scale rows between lateral line and dorsal-fin origin; 8-12 rakers on first gill arch; 7-9 predorsal scales; 14 circumpeduncular scale rows; usually two scale rows separating vent and anal-fin; <29 lateral line scales; 9-14 serrations on the spinous dorsal-fin ray; distance between distal serrae on posterior margin of last unbranched dorsal-fin ray much greater than the width of their bases.

It is very similar to H. wetmorei but can be told apart by possessing yellow (vs. orange to red in H. wetmorei) pectoral, pelvic, and anal fins. It thus appears likely that yellow-finned fish marketed as H. wetmorei or ‘lemon fin barb’ in the ornamental trade are actually H. vernayi, with both species available on a regular basis.

Endemic to the Salween river system in Yunnan province, southern China, eastern Myanmar, and northwestern Thailand.

Type locality is ‘Salween River midway between Mae Sam Laep and Paleh, Mae Hong Son province, Thailand.’

Known from the middle and lower Mekong basins in Laos, Thailand, Cambodia, and Vietnam, plus the Dong Nai drainage in central Vietnam.

Type locality is ‘Rapids of Dang-nai, Bien Hoa Province, Thailand’, which corresponds to what is now the city of Biên Hòa in Đồng Nai province, southern Vietnam.

H. malcolmi is distinguished from congeners by the following combination of characters: 12-17 (usually 14-15) rakers on first gill arch; usually 16 circumpeduncular scale rows; less than 30 lateral line scales; some branched lateral line canals, but branching not extensive, median portion of dorsal-fin dark.

This species is migratory on a seasonal basis; during the dry season it can be found in larger river channels, whereas during drier months it moves into smaller tributaries and flooded forests.

Apparently displays a preference for rocky habitats and is not known to adapt to reservoirs or other artificial impoundments.