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.

This species is seen in the aquarium trade on a relatively frequent basis and is sometimes sold as ‘bicolor loach’ in the United States.

It can be distinguished from congeners by its unique colour pattern comprising 9-10 thin, yellowish bars on a dark background in the upper part of the body, and plain whitish colouration in the lower portion.

Type locality is the ‘river below Calcutta’ which corresponds to the western side of the Ganges River delta south of Kolkata, West Bengal state, with reports as to its wider distribution varying significantly.

It’s sometimes said to be present throughout India plus both mainland and maritime southeast Asia, but is more likely restricted to India, Bangladesh, Sri Lanka, and possibly Myanmar.

Barilius spp. are near-exclusive surface-feeders preying mostly on flying insects in nature with some small fishes and benthic invertebrates probably taken as well but in the aquarium they’re largely unfussy and will accept most foods.

Like many fishes that naturally inhabit running waters it’s intolerant to the accumulation of organic wastes and requires spotless water at all times in order to thrive. It also does best if there is a high proportion of dissolved oxygen and moderate degree of water movement so external filters, powerheads, airstones, etc., should be employed as necessary.

This species has been widely regarded as a member of the genus Nemacheilus since the late 1970s with the vast majority of subsequent authors considering it as such, although in the aquarium hobby it’s more commonly referred to Schistura.

Probably a micropredator feeding on small insects, worms, crustaceans and other zooplankton in nature. In the aquarium it should accept dried foods of a suitable size but should not be fed these exclusively.

Daily meals of small live and frozen fare such as Daphnia, Artemia, Moina, etc., along with good quality flakes and granules will result in the best colouration and encourage the fish to come into breeding condition.

Type locality is given as ‘Cedawáti [Vedawati] stream, headwaters of Krishna River near Heriuru, Mysore, India’, with the species currently considered to occur throughout India, Bangladesh, Nepal, and probably Bhutan.

It’s also been recorded in Pakistan, Myanmar, Thailand and Sri Lanka although some or all of these reports may refer to other species.

This species occasionally appears in the ornamental trade, usually as ‘striped hill trout’ or ‘banded hill trout’.

It can be distinguished from congeners by the following combination of characters: lateral line complete with 40-42 scales; barbels absent; 10-13 anal-fin rays; body with 9-11 dark blue vertical bars; last dorsal-fin ray extending to caudal-fin base.