Probably endemic to northern India, Bangladesh, and Nepal. Records from Sri Lanka, southern India, Myanmar, Thailand, Laos, Cambodia, Vietnam, Malaysia, and Indonesia appear to represent other species.

Given the distribution of L. siamensis, it seems likely that many of the fish entering the aquarium trade are this species and not L. laubuca. The two species can be distinguished b…

Following Roberts (1997) G. ariza can be diagnosed by the following combination of characters: body with variably intense thin stripes dustributed mostly above the lateral line; larger individuals sometimes with a broad midlateral stripe; 32-35 lateral scales; 7-8/1/5-6 transverse scale rows; 8-9 branched dorsal-fin rays 8-9; 22-24+ 11-12=34(4), 35 (3) vertebrae; live colour pattern variable, overall dull dirty white to greyish, silvery or yellow.

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.

Found in various types of habitat but shows a marked preference for shallow, slow-moving and standing waters such as rice paddies and other temporally-inundated environments with dense aquatic vegetation.

Despite being a wholly unsuitable aquarium subject, C. idella is often traded as such, with an albino form having been developed specifically for the ornamental market.

Individuals which have outgrown their aquarium or pond should never be released into natural waters, either, since this species has proven capable of causing serious environmental damage under a wide range of climatic conditions.

It is currently the only valid member of the genus but it is possible that additional taxa exist, particularly in Myanmar, while a number of former species are contained within the Laubuka assemblage, to which C. cachius is closely related. Phylogenetic studies suggest the existence of a monophyletic clade consisting of the genera Devario, Chela, Laubuca, Microdevario and Microrasbora plus the genus Betadevario.

There is considerable confusion surrounding the identity of B. bagarius with its name having been widely applied to a relatively small species that is said to reach only 200 mm SL and considered to be common in northern India and much of Indochina.

This species is clearly unsuitable for the home aquarium given its eventual size and natural behaviour, and we know of only a handful of private aquarists with the facilities required to house it long-term.

The grouping currently contains four species but is in urgent need of review with a number of additional taxa thought to exist and B. yarrelli possibly representing a synonym of B. bagarius.