One of the more commonly-traded members of the genus and often found in mixed shipments which may contain other Gastromyzon spp. or related fishes like Beaufortia kweichowensis, these often labelled collectively as ‘Borneo sucker’, ‘Hong Kong pleco’, ‘butterfly loach’, etc. It’s sometimes misidentified as G. punctulatus, a species not currently traded which possesses yellow finnage and a lighter-coloured, less-intensely spotted body.

This species is one of several traded variously as 'butterfly loach', 'butterfly plec', 'Hong Kong plec(o)', 'Chinese hillstream loach' or simply 'hill stream loach'. In many countries it's the most common balitorid in the shops but is also often found in mixed shipments containing members of other genera.

Like all balitorids it's an obligate bottom-dweller with specialised morphology adapted to life in fast-flowing water. The paire…

Field observations have revealed that individuals almost always position themselves facing into the flow, either along the sides, behind or under rocks, their specialised morphology (see ‘Notes’) allowing them to feed and maintain position without being swept away.

Not many fishes have been able to successfully colonise this narrow ecological niche, but syntopic species in nature include Gastromyzon extrorsus (Petagas River), G. introrsus, G. lepidogaster (Pad…

Annamia spp. may be confused with related genera such as those of the genus Balitoropsis. They can be identified by their more depressed body shape, elongate lower caudal-fin lobe, and the presence of a single unbranched ray in the pectoral and pelvic fins. At least one undescribed member of the genus is thought to exist.

At one locality close to Ban Na Hwai, Chiang Mai Province, Thailand L. hasselti was collected from a shallow (<0.5 m) pool in a swampy zone between forest and rice fields. The substrate was of mud, there was no aquatic vegetation and it was being used as drinking water by local animals, with the only effluent connected to a 'small creek'. Other species found there were Physoschistura pseudobrunneana, Rasbora hobelmani and Systomus cf. orphoides.

This fish occasionally turns up as a contaminant in shipments of A. sp. 'AR01'. The latter is usually traded as A. elongatus but that species appears endemic to higher altitude waters of the Brahmaputra drainage in Darjeeling District which borders Jalpaiguri to the north east. These flow down from the Sivalik Hills whereas the Raidak I originates in Bhutan. Only three species of Aborichthys have been officially described to date meaning this is likely to represent an undescribed speci…

Within the nominal species grouping suggested by Grant (2007) almost all B. rostrata sold in the hobby are B. sp. 'upper Brahmaputra' with B. rostrata sensu stricto rarely, if ever, available. Trade names include 'Gangetic loach', 'twin-banded loach' and 'ladder loach'. The defining characters of the group are "Pattern consisiting of 8-10 black to dark brown body bars that exhibit pale and numerous spots in juveniles, and in adults the bars can anast…

Adult patterning of the different geographical forms can vary considerably though young specimens all possess 5 solid dark bars on each flank and are often confused with those species exhibiting a similar juvenile pattern, particularly B. kubotai. However the horizontal dark bars on the flanks in B. kubotai typically split at quite a young age and/or develop horizontally-orientated ‘peaks’ whereas those in B. histrionica remain solid for longer and the central bar usually has a pale spot at the top so forms a ‘y’ shape.

To date known only from the Jaintia Hills district, Meghalaya state, northeastern India meaning its natural waters are part of the Brahmaputra River system. The type locality is given as ‘Tre Rangriang, Jowai’ in the description paper, but we’ve been unable to locate this on any map. The paratypes were collected at ‘Thlu Muwi’, which probably refers to the ancient stone bridge built over the Muwi stream, a place popular with tourists due to the nearby Muwi waterfalls.

Appears to be endemic to headwaters of the Salween River basin around the border between Myanmar and Thailand. The type specimens were collected from the Megathat Chaung (Megathat stream) in the upper Ataran (known as the Kasat in Thai) River basin, Kayin/Karen State, Myanmar and another population was later discovered in the Hanthayaw River (Suriya in Thai), Tak Province, Thailand.