Ganges basin

The half-banded loach, Acoura savona, is a nemacheilid loach from Ganges tributaries draining the eastern Himalayas in India, Nepal and Bangladesh. The species is seen in the trade fairly often and is sometimes sold as 'bicolor loach' in the United States. Its colour pattern of 9-10 thin, yellowish bars on a dark upper body, with plain whitish lower parts, separates it from similar loaches, and it is among the less aggressive of them.

The badis, Badis badis, is a small badid from the Ganges river system in India, Nepal and Bangladesh, with further records in Assam and the Mahanadi. Sometimes sold as the 'chameleon fish' for its ability to change colour rapidly, especially when breeding or stressed, it was one of only two badids popular in the hobby before 2002. Several congeners share its dark cleithral spot and can be hard to tell apart. It is sluggish and retiring, and rival males can be quite aggressive towards one another in confined spaces.

Barilius bendelisis is a large, fast-swimming cyprinid from India, Bangladesh, Nepal and probably Bhutan. Occasionally sold as 'Indian hill trout' or 'Hamilton's baril', it has 8 to 12 bluish vertical bars and, in adults, a blue-black spot on each scale. It grows to around 200 mm SL and inhabits well-oxygenated, fast-flowing rivers and streams, and its speed and vigorous feeding make it unsuitable for the general community.

Barilius shacra is a cyprinid from the Himalayan foothills of Nepal and northern India, in the Ganges and Brahmaputra systems, and from Bangladesh. Poorly known in the hobby but exported on occasion, it has around 12 vertical bars on each flank and a black band in the upper third of the dorsal fin. It inhabits well-oxygenated, fast-flowing rivers with gravel, cobble and boulder substrates, and is too fast and vigorous a feeder for the general community.

Barilius vagra is a cyprinid widely distributed in the Ganges and Brahmaputra river systems of northern India, Nepal and Bangladesh. Poorly known in the hobby but exported on occasion, it has 10 to 14 vertical bars on each flank that do not extend below the lateral line. It inhabits well-oxygenated, fast-flowing rivers and tributaries with gravel, cobble and boulder substrates, and its speed and vigorous feeding make it unsuitable for the general community.

The yo-yo loach, Botia almorhae, is a botiid loach from parts of the Ganges River drainage in northern India and possibly Nepal. It is often called the 'Pakistani' loach, but that name is a misnomer. B. almorhae sensu stricto appears to belong to a group of closely-related species and has possibly never been seen in the aquarium trade, where the most commonly available members seem to be B. lohachata, B. sp. 'Kosi' and B. sp. 'Teesta', plus assorted hybrids.

The moose-faced loach, Canthophrys gongota, is a cobitid loach from the Ganges and Brahmaputra river systems in Nepal, northern India and Bangladesh. Often referred to as Somileptes gongota in aquarium literature, it is rarely seen in the trade, being notoriously delicate and difficult to ship. It mostly inhabits slow-moving, shallow tributaries and minor rivers over mud, sand or gravel.

Chagunius chagunio is a large cyprinid endemic to the Ganges and Brahmaputra river basins in northern India, Nepal and Bangladesh. Growing to 400-450 mm, it can only be considered suitable for public aquaria and a very small minority of private aquarists. Rarely seen in the trade, it looks almost identical to C. baileyi and C. nicholsi but has more circumferential and circumpeduncular scales.

Crossocheilus latius is a cyprinid widespread in India, described from the Tista River on the border with Bangladesh. It lives everywhere from boulder-strewn Himalayan hill streams to silt-laden tributaries and pools. Not often available in the trade, it sometimes turns up in shipments of Indian Garra, and its relatively plain pattern makes it unlikely to be confused with congeners. Juveniles are gregarious and active, but adults tend to become sedentary and solitary.

Devario assamensis is a deep-bodied devario from Assam and West Bengal in northeastern India, in tributaries of the lower Brahmaputra. It has been traded as Devario sp. 'Mirik red', D. sp. 'redline' and D. sp. 'blood stripe', but is very rare in the hobby. If the distribution records are correct, it occurs from around 250 m AMSL in Darrang to 1767 m at Mirik, and possibly higher in Bhutan.

Lepidocephalichthys annandalei is a cobitid loach from the mid-to-lower Ganges and Brahmaputra systems in Nepal, Bangladesh and north-east India. Rarely traded, it has been sold as L. sp. 'peacock', presumably for its caudal-fin pattern of two dark v-shaped markings, unique within the genus. Fish in the trade differ slightly from the original description, in particular lacking a notched caudal fin.

Nemacheilus anguilla is a loach endemic to the Western Ghats of southwestern India, recorded from rivers in Maharashtra, Karnataka and Kerala. Dark flank markings merged into a lateral stripe separate it from other Indian congeners, and its generic placement requires further study. It inhabits well-oxygenated, moderate to fast-flowing rivers over gravel and boulders, and is peaceful with its own kind, best kept in a group of four or more.

Traded as 'striped hill trout' or 'banded hill trout', Opsarius barna is a cyprinid from the Ganges and Brahmaputra basins in northern India. It is thought to also occur in the Mahanadi and in river systems in Nepal, Bhutan, Bangladesh and Rakhine State, Myanmar, in well-oxygenated, fast-flowing rivers over gravel, cobbles and boulders. An extremely fast swimmer and vigorous feeder, it is unsuitable for the general community.

The glass barb, Puntius guganio, is a small cyprinid widespread in the Ganges and Brahmaputra river systems of Bangladesh, Nepal and northern India. It lives in slow-moving or standing waters such as pools, ditches and minor rivers. Poorly known in the hobby, it is of uncertain taxonomic placement, and its stiff, serrated last dorsal-fin ray, incomplete lateral line and 36-39 lateral scales are shared only with 'P.' nangalensis.

Puntius mahecola is a cyprinid from rivers draining much of the Western Ghats mountains in Kerala, Karnataka and Tamil Nadu states, southern India. The name was misapplied to members of Dawkinsia for over a century, while the fish itself was widely misidentified as P. amphibius. A relatively plain fish, it has a single dark blotch on the caudal peduncle behind the anal fin. D. assimilis and other Dawkinsia species appear on trade lists as 'mahecola barb'.

The bullseye snakehead, Channa marulius, is a large snakehead recorded from Pakistan across southern Asia to southern China, Laos and Vietnam. Also called the 'giant', 'cobra' or 'Indian' snakehead, it is widely accepted to represent a complex of related species in need of further research. Reports of 120-180 cm remain to be proven, with 500-600 mm a more common adult size, and it is suitable only for public installations or the very largest private aquaria.

The Indian featherback, Chitala chitala, is a very large notopterid probably restricted to Pakistan, India, Nepal and Bangladesh. Its name has been widely misapplied in the trade, most often to the Southeast Asian C. ornata, but it is very rarely exported for aquaria and is fished and cultured for food in India. Growing to 1220 mm SL, it has non-ocellated black spots above the anal fin and is the only Chitala normally showing gold or silver bars on the back.

The bronze featherback, Notopterus notopterus, is an air-breathing notopterid from the Indian subcontinent and Southeast Asia. Also called 'Asian knifefish' or 'ghost knifefish' in the trade, it grows to 600 mm and arguably has no place in the ornamental hobby given its adult size and specialised requirements. The single species in Notopterus is likely to represent a complex of closely-related species.

Labeo angra is a benthic cyprinid from Pakistan, Nepal, northern India, Bangladesh and Myanmar, described from the Brahmaputra. It can be identified by a brownish back, yellowish flanks and belly, and a black to bluish stripe from the eye to the caudal-fin base. It undertakes annual spawning migrations within its native river systems.