We’ve been unable to obtain a diagnosis for this species to date but it can at least be distinguished from those congeners traded as ‘Crossocheilus siamensis’ (an invalid name synonymous with C. oblongus, which is itself of questionable identity), ‘Siamese algae eater’, or ‘SAE’ by the fact that the dark lateral stripe does not extend into the caudal-fin.

Members of Crossocheilus are characterised by…

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.

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.

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.

This species is also referred to as ‘giant’, ‘great’, ‘cobra’, or ‘Indian’ snakehead.

Although currently-considered to be distributed throughout much of southern Asia it is widely-accepted to represent a complex of related species in need of additional research.

A number of geographical variants exhibiting diffe…

This species has not yet entered the aquarium trade but is maintained by a handful of private collectors.

Though described in 2012 it was in fact first collected in the latter half of the 19th century with Day (1875-1878) having mentioned the presence of Badis dario in ‘Wynaad’ and its occurrence “along the Western Ghats” (the chain of mountains in southwestern India).

This species was considered to be a phenotype of the similar-looking P. gelius prior to its description.

Following Knight (2013) it is included a group of closely-related species alongside P. gelius and P. canius, the trio being distinguished from other members of the genus Pethia by the following combination of characters: lateral line incomplete with 3-4 por…

This species’ identity was settled and a neotype designated by Knight (2013), with its validity having been discussed since the late 19th century.

P. canius and the closely-related P. gelius were both described by Hamilton (1822) and share the type locality of ‘northeastern Bengal’. Although Hamilton did not provide drawings M’Clelland (1839) included colour illustrations depicting two quite different-looking species.

Appears endemic to tributaries of the Bhavani river system in the Nilgiri Hills of Tamil Nadu state, southern India including the Pykara, Avalanche and Kaity streams.

Type locality is ‘Ootacamund Lake, Pykara, Avelanche and Kaity streams, Neilgherry Hills, India’, with the former now often shortened to Ooty Lake.