Loaches

This fish 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 species. It was pictured in Tekriwal and Rao (1999) under the name 'A. bijulensis' but...

A. sinuata is currently considered a synonym of A. mooreh by most authorities. This appears attributable to a lack of recent study since the two differ in distribution plu...

Acanthopsoides spp. are most closely related to the horse-faced loaches of the genus Acantopsis with which they often co-occur in nature, and thus commonly referred to as 'dwarf horse-face loaches'. The genus currently comprises five species of which four were described by Siebert (1991); these were discovered in existing museum holdings...

Acanthopsoides spp. are most closely related to the horse-faced loaches of the genus Acantopsis with which they often co-occur in nature, and thus commonly referred to as 'dwarf horse-face loaches'. Most are very difficult to tell apart but A. robertsi is quite easily identified since it's the only...

Acanthopsoides spp. are most closely related to the horse-faced loaches of the genus Acantopsis with which they often co-occur in nature, and thus commonly referred to as 'dwarf horse-face loaches'.

Acanthopsoides spp. are most closely related to the horse-faced loaches of the genus Acantopsis with which they often co-occur in nature, and thus commonly referred to as 'dwarf horse-face loaches'. The genus currently comprises five species of which four were described by Siebert (1991);...

Juveniles of this 'species' (probably a group of species - see 'distribution') are traded in large numbers but it's still uncommon to see adult specimens in the hobby suggesting their needs are not catered for often enough. This is a shame as when maintained properly they're hardy, long-lived and interesting aquarium residents. Other trade names include 'long-nosed' and 'banana' loach. Please note although certain that more than one species is being tr...

This species was lost to the hobby for several years prior to the turn of the century and when commercially-produced stock first came onto the market prices were very high. It's now readily available, though, and while never particularly cheap is considerably less expensive.

Traditionally considered to be a micropredator feeding on insect larvae and suchlike (Rainboth, 1996), but a study by Herder and Freyhof (2006) revealed adult A. normani inhabiting the Duc My River in central Vietnam to be specialised grazers of cyanobacteria. In rapids the latter form hard encrustations on rock surfaces from which adults are able to bite chunks.

Known only from a handful of localities within the Xi River (Xi Jiang) drainage in Guangxi Zhuang Autonomous Region, southern China plus the Tuoniang river system in Funing County, southeastern Yunnan province. Type locality is 'West River, Longzhow Xian, Guangxi Province, China'.

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...

At time of writing there exist 18 recognised members of the genus though only B. kweichowensis is well-known in the trade with B. szechuanensis unlikely to have been exported. According to Chen, Huang and Yang (2009) it can be distinguished from similar congeners by the following suite of characters: 1 branched and 17-20 simple pectoral-fin rays...

The physical appearance of B. almorhae sensu stricto is something of a mystery. No pictures of live specimens appear in any scientific publications we've read and we've been unable to find a certified image of one anywhere meaning it's possibly never been seen in the aquarium trade. Instead the most commonly available members of the nominal species grouping seem to be B. lohachata, B. sp. 'Kosi' and B. sp. 'Teesta' (see individual notes below), plus the assorted hybrids that have appeared since the turn of the century (Grant, 2007).

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.

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.

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...

In a survey of fish diversity in the Bhadra River (which joins the Tunga to form the Tungabhadra) it was recorded alongside numerous other species including Puntius chola, Balitora mysorensis, and Mystus armatus. Dry season water paramaters were temperature 69.8°F/21°C, pH 7.0, hardness ~ 2.5°. The substrate was composed of bedrock, boulders, cobbles, gravel, sand and leaf litter in descending order of abundance with a maximum depth of around...

Known only from the Tanintharyi River drainage in Tanintharyi (previously Tenasserim) Division, southern Myanmar. Tanintharyi lies on the Kra Isthmus and the river bisects the central zone north-to-south before emptying into the Andaman Sea at Mergui/Myeik. This area is not easy to access for fish collectors due to occasional conflict between the Myanma...

E. sinensis was initially included in the genus Protomyzon where it remained until 2004 when Kottelat found sufficient geographical and morphological differences between members of the group inhabiting the island of Borneo and those from mainland East/South East Asia to warrant their separation. The genus Erromyzon was erected to accommodate the mainland fishes and there are currently three...

Erromyzon spp. are obligate dwellers of shallow, fast-flowing, highly-oxygenated headwaters/minor tributaries characterised by stretches of riffles and runs broken up by pools or cascades in some cases. Substrates are normally composed of smaller rocks, sand and gravel with jumbles of boulders, and while riparian/stream-side vegetation and patches of submerged leaf litter are common features aquatic plants aren't usually present.

This fish remains in need of identification, and we've chosen to list unidentified members of the genus using an 'ER' numbering system in the absence of definitive information. It's quite easy to distinguish from congeners since it's the only species known to possess a colour pattern comprising a dark base colour and series of thin, paler vertical bars on the body and similarly-coloured spots on the head.

An obligate dwellers of swiftly-flowing streams and headwaters containing clear, oxygen-saturated water. It inhabits riffles and runs and according to studies shows a preference for shallower zones. Substrates are generally composed of gravel, rocks, boulders or bedrock carpeted with a rich biofilm formed by algae and other micro-organisms. Aquatic plants are uncommon and while riparian/streamside vegetation may be present...

It's most easily told apart from K. brevifasciata, its only congener, by body patterning consisting of dark, vertical bars running along the dorso-ventral part of the body (vs. dark bars running alongside the midventral part of the body), lips with wrinkled surfaces (vs. smooth) and barbels short (vs. long).

This is one of the most frequently-traded members of the genus and is an excellent choice for those new to keeping loaches. It's distinguishable from congeners by a combination of characters including: relatively large adult size (to at least 80 mm SL); rounded/truncate caud...

This species is almost unheard of in the hobby with the specimen pictured above the only one we're aware of. It was imported into the United Kingdom in late 2011 as bycatch among a shipment of mastacembelid eels from northern India, and the identification was subsequently confirmed by Justin Havird, senior author of the most recent revision of the genus.

This is one of the most frequently-traded members of the group and is an excellent choice for those new to keeping loaches. It's distinguishable from congeners by a combination of characters including: rounded/truncate caudal-fin; a scaleless patch on top of the head; relatively large adult size; flanks with spotted patterning in females and a solid...

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.

The family Cobitidae, often referred to as 'true' loaches, is widely-distributed across most of Eurasia with the Indian subcontinent, Southeast Asia and China representing particular centres of species diversity. Phylogenetic analyses by Tang et al. (2006), Šlechtová et al. (2007) and Šlechtová et a...

This species is available sporadically and makes an excellent choice for those new to keeping loaches. It's distinguishable from congeners by a combination of characters including: truncate/rounded caudal-fin; no scales on top of head; dark, squarish spots o...

However, according to the identification key of Rema Devi and Indra (2002), the two can be distinguished by a combination of factors as follows: body spots rounded in shape (vs. 'Y' or 'V' shaped in M. herrei); caudal peduncle relatively long (vs. relatively short); anal-fin not reaching base of caudal-fin (vs. anal-fin reaching base of caudal-fin); caudal peduncle with a dark band (vs. caudal peduncle with a dark spot); sub...

It's unclear if this species has ever been exported for the aquarium hobby outside of India but there may be a chance of finding the occasional specimen mixed in with shipments of M. guentheri or M. triangularis. It was earlier considered synonymous and may still be confused with M. guentheri since both species share similar body patterning consisting of rows of yellowish, dark-edged spots.

Type locality is 'Netravati River, Dharmasthala, Karnataka State, India', with the species subsequently recorded from the Kabini (aka Kabani) River basin and it may be endemic to these two drainages. While the Netraviti flows through Karnataka in its entirety before emptying into the Arabian Sea just south of the city of Mangalore, th...

This species was initially described as a member of Cobitis and remained as such for over 60 years until being redescribed in the new genus Microcobitis by Bohlen and Harant (2011). It can be separated from Cobitis species by a number of char...

This species is traded under various names including 'Vietnamese multi-banded zebra loach', 'hovering zebra loach', 'Laos pygmy multi-stripe loach', and 'banded dwarf loach'. It can be distinguished from related species by the following combination of characters: body with distinct vertical bars; 8 branched dorsal-fin rays; 3-10 pored lateral line scales; one pair of large papillae in median portion of upper lip; two pairs of large papillae in median portion of lower lip; lower posterior edge of opercle with 3-4 prominent indentations.

It's actually sold in the aquarium hobby on a regular basis but almost always labelled as or mixed in with Misgurnus anguillicaudatus and is thus poorly documented. Although quite simi...

'N.' anguilla can be told apart from other Indian members of the genus by possessing dark flank markings which are partially or completely merged to form a lateral stripe, and an almost-complete lateral line extending to the anal-fin. Kottelat (2012) states that its generic placement requires additional study hence the genus name i...

N. binotatus is distinguished from similar-looking congeners such as N. longistriatus and N. ornatus by its unique body patterning consisting very simply of two dark stripes, one running along the dorsal surface and the other from the tip of the snout, through the eye and along the flank. There are usually 1-3 small, vertically-orientated spots extending above the lateral stripe between the pectoral-fin and dorsal fins. These are su...

This species was originally named Nemacheilus masyae but following ICZN rules the spelling was later corrected to N. masyai because it's named after a man. It can be distinguished from the majority of congeners by body patterning comprising 14-18 short, dark vertical bars on each flank, 12-17 saddle-like markings running along the dorsal surface, a dark spot on the caudal peduncle at the termination of the lateral line and a dark blotch in the lower half of the first few dorsal-fin rays.

This species is distinguished from similar-looking congeners such as N. longistriatus and N. ornatus by its unique colour pattern consisting of a black lateral body stripe with 9-16 vertically-orientated blotches extending along it both above and below, plus an irregular stripe running along the dorsal surface. The anterior lateral blotch is surrounded by lighter pigment, forming an ocellus similar to that seen in N. binotatus.

This species is only traded occasionally. It's distinguished from congeners by a combination of characters including: 12-16 dark, irregular, vertical bars on body, usually split vertically; lips without furrows; inco...

Images depict clear, tea-coloured forest streams with dense marginal vegetation and substrates of sand and/or small rocks and pebbles. It's also known from environments with sandy substrate and organic debris in the form of submerged roots/branches and le...

N. selangoricus is most similar to N. spiniferus since it possesses acuminate scales above and below the lateral line on the caudal peduncle, a feature not shared with any other congener. It can however be distinguished by the following characters: presence of 8-12 very regular dark bars on flanks (vs. 10-13 irregularly-shaped bars in N. spiniferus), 3-5 times...

It's a member of the N. selangoricus group of species within the genus, an assemblage first recognised by Hadiaty and Kottelat (2009) and characterised by possession of two rows of horizontally-arran...

This species is frequently misidentified as Nemachilichthys rueppelli (Sykes, 1839) but that species was described from close to Pune in Maharashtra state, well over 500 km north of Shimoga. Further, in his description of N. rueppeli Sykes states that the body colour is 'greenish yellow' and 'the lateral line marked with short dark bars'. Narayan Rao described the colour pattern of...

It's included in the P. kuhlii group of closely-related species and can be distinguished from other members by the following combination of characters: 8-11 very broad, quadrangular, regular dark body bars; orange base body colour; caudal-fin either entirely black or with a large black blotch at the base and a submarginal dark bar or row of spots. The latter feature can be useful in identifying young or newly-imported, undernourished specimens which can...

Described from close to the city of Bogor, Jawa Barat (West Java) province on the island of Java, Indonesia, but currently considered widespread with recorded occurrences on Java, Sumatra, Borneo and mainland Peninsular Malaysia. Some populations exhibit lighter...

This species is among the most frequently-misidentified in the hobby, almost always being traded as P. kuhlii. However the latter is currently considered endemic to Java, from where commercial collections are almost unheard of, and has possibly never been seen in aquaria.

Patterning is highly variable depending both within and between populations and the species may comprise an assemblage containing a number of taxa (Kottelat and Lim, 1993; Tan and Kottelat, 2009). For example, those from Singapore and Johor possessing intricate mottling on the dorsal surface while individuals from Terengganu have a series of saddle-like markings either alternating or connecting with the midlateral markings.

The fish in our images above were imported together don't correspond to any of the described species of Pangio though they can be assigned to the P. kuhlii species group with a degree of certainty. Unfortunately the live appearance of P. kuhlii itself is a mystery to aquarists since it's currently considered endemic to Java and may have never been seen in the hobby.

The fish in our images don't correspond to any of the described members of the genus but can be assigned to the P. oblonga species group with a degree of certainty. It's apparently exported as a contaminant among shipments of a uniformly brown-coloured fish with unpublished genetic analyses suggesting the two might be variants of the same species (J. Bohlen, pers. comm.). Among congeners it may be related to P. alcoides Kottela...

Pangio species are often generically referred to as 'kuhli' or 'coolie' loaches in the aquarium hobby, the latter a variation of the former which was itself derived from the surname of German naturalist Heinrich Kuhl (1797-1821). Ichthyo...

This unidentified species has been traded since the mid-00s and appears to be a member of the P. khulii-oblonga species group as per Bohlen et al. (2011). There are two similar-looking forms; one has a darker body, dark pigmentation in the pectoral fins and barbels and a blue sheen on the head, while the...

Traded under various names including 'mottled', 'eyepot', 'sand' and 'striped' loach. It's perhaps one of the better choices for those new to keeping nemacheilids being relatively hardy, peaceful and exhibiting some quirky behavioural traits. The characteristic ocellus, a dark marking at the top of the caudal peduncle that resembles an eye, is thought to have some function in predator distraction and is normally more intense in younger specimens.

This species is still considered a member of the genus Nemacheilus by some sources, but it was reclassified and placed in Acanthocobitis by Grant (2008). Acanthocobitis sinuata, generally considered a junior synonym of A. mooreh (Kottelat, 2012b), also appears distinct and differs in geographical distribution plus number of dorsal-fin rays (2-3/9-10 in A. mooreh vs. 2/8-9 in A. sinuata) and some aspects of colour pattern.

According to Kottelat (1990) the chief distinguishing characters for the genus are: possession of 9-18½ branched dorsal-fin rays; colour pattern without black basal caudal bar, but with an ocellus at upper base of caudal-fin; upper lip with or without several rows of papillae; lower lip with a broad median interruption and a widened, papillated pad on each side.

This species is sometimes traded as 'Lake Inle red-tailed loach' and was formerly included in the genus Yunnanilus, a diverse assemblage of which the majority of members are endemic to the Yunnan plateau in Yunnan province, southern China.

This species continues to be referred to by the fictitious scientific name 'Tuberoschistura arakensis' but actually appears to be an undescribed Yunnanilus sp. and is also sometimes traded as Y. sp. 'orange' or 'Burmese pink loach' but appears to be a member of the genus Petruichthys as per Kottelat (2012). There exist more than 30 described Yunnanilus spp., the...

Fishes which inhabit similar biotopes in nature constitute the best options, especially peaceful, open water-dwelling cyprinids since the presence of one or two schools can make a visible difference to the confidence of this naturally reclusive loach.

Schistura species are omnivorous although the bulk of their diet consists of small insects, worms, crustaceans and other zooplankton with only relatively small amounts of plant matter consumed, mostly via the stomach contents of prey items. In the aquarium they will acc...

This species exhibits some interesting behaviour including a degree of social interaction plus the ability to cling to vertical or overhanging surfaces. It's sometimes sold under the name 'serpent loach'. The genus currently contains just three members all of which are known only from the Mekong basin. S. octozona is the type species and separated from the others mainly by body patterning which consists of 7-8 dark bars on each flank, these extending the full depth of the body and much wider than the pale interspaces between.

It's been suggested that these two may represent the same species but this appears not to be the case. When describing S. albisuera Freyhof (2003) used a series of specimens collected in 2000 plus some larger, spotted fish which had been collected in 1999 and preserved in New York. Although he noticed differences in dorsal patterning between the two series these weren't considered sufficient to s...

S. lineolata was first recorded by Diard over 150 years prior to its 'rediscovery' in the early-1990s. It became available to the aquarium trade in the mid-2000s and swiftly established itself as one of the more popular balitorids in the hobby due to its attractive body markings and ease of breeding. It's also sold under the names 'reticulated hillstream loach', 'Vietnamese hillstream loach' and 'gold ring butterfly sucker'. It's difficult to...

This species first became available in early 2009 and was initially identified as S. breviventralis (Freyhof and Serov, 2000) because there is a clear space between the pelvic and anal fins and body patterning is vaguely similar to that species, and also appears quite similar to S. elongata (Roberts, 1998) and S. sp. 'SEW03'. It does not fully match the original descriptions of either, however, and therefore remains in need of identification.

This fish first became available in early 2009 and was initially identified as S. breviventralis (Freyhof and Serov, 2000). However it cannot be that species because there is no discernible gap between pelvic and anal fins, which also discounts the possibility of it being S. elongata (Roberts, 1998). It therefore remains unidentified and is often imported in mixed batches with S. sp. 'SEW02', which it also resembles closely.

This fish has thus far only been imported among shipments of S. sp. 'SEW02' and S. sp. 'SEW03'. It doesn't appear to correspond to any known member of the genus and may be undescribed. Prior to the mid-1990s S. lineolata was the only species in the genus but an upturn in surveys of fresh water fauna in Vietnam and Laos has resulted in the discovery of various new taxa, several of which remain undescribed.

This species first became available in early 2010 and sometimes appears on trade lists under the vernacular names 'Laos sucker' or 'Laos Sakura sucker'. It's distinguishable from other members of the genus by the following combination of characters: body spotted and without stripes; no concentric bands on paired fins; origin of pelvic-fin below origin of dorsal-fin; origin of pectoral-fin posterior to corner of mouth; pelvic fin reaching origin of anal fin; small elevated ...

This species is also sold under the vernacular names 'golden Chinese loach' and '12-banded Chinese loach'. Along with S. robusta it's the most commonly-traded member of the genus, and the two are often imported in mixed batches, presumably because they occur and are thus collected together in nature. Like most congeners it has a highly flexible, sinuous body which makes it very interesting to observe. S. pulchra can be differentiated from...

This species not often seen in the aquarium trade and is apparently rare in its natural waters, with the occasional individual imported as bycatch in shipments of S. pulchra or S. robusta, or by private collectors. Like others in the genus it has a highly flexible, sinuous body which makes it very interesting to observe. It's told apart from congeners by the following combination of chara...

This species is also sold under the vernacular names 'golden Chinese loach' and '12-banded Chinese loach'. Along with S. pulchra it's the most commonly-traded member of the genus, and the two are often imported in mixed batches, presumably because they occur and are thus collected together in nature.

This species is rarely-seen in the trade due to a relative lack of commercial exports from the middle Yangtze basin. It looks very similar to S. pulchra but can be told apart by the fact it lacks irregular, brownish markings and spots on the side of the head (vs. present in S. pulchra), and like most congeners it has a highly flexible, sinuous body which makes it very interesting to observe.

This species is traded under various names including 'chocolate scissor-tailed loach', chocolate long-finned loach', 'red line cobra loach', 'spiny eel loach' and 'dragon loach'. It's apparently difficult to find in its natural habitats and thus time-consuming to collect, meaning it's rarely traded in numbers, sought after by enthusiasts and tends to carry a relatively high price tag when available. The genus currently contains just three...

Juvenile specimens were first exported for the aquarium hobby during 2009 and have since been available on a sporadic basis with prices generally reflecting its rarity and, hopefully, number of specimens being collected. The striking black-and-white-striped juvenile colour pattern inspired the vernacular name although it's sometimes labelled as 'panda goby' rather than 'panda loach'.

This specie is relatively rare in the aquarium trade and much sought after by enthusiasts as a result. It looks relatively similar to Y. splendida but can be told apart from it, and indeed all other members of the genus, by the following combination of characters: possession of 8 branched dorsal-fin rays; 32-33 vertebrae; one or two small, brownish, vertically-orientated markings on the dorsal part of the body posterior to the dorsal fi...

This species first appeared in the trade during 2009 with prices initially variable but in the main prohibitively expensive, and it remains expensive when available. We've seen it on sale under various names including 'jaguar loach', 'splendid loach' and 'yellow-tail polka dot loach'. It appears superficially similar to Y. caudipunctata, Y. longidorsalis and Y. morleti but can be distinguished from all by a combination of characters of which the most immedia...

The identity of this fish is somewhat unclear although it's available in the aquarium trade on an occasional basis. It's been considered to represent various species including Schistura beavani, S. montana and S. himachalensis but there exi...

Following Kottelat (1990) the genus Nemacheilus is characterised by a combination of characters as follows: elongate body; complete lateral line; presence of enlarged scales above and below the lateral line in some species; caudal-fin forked to deeply forked with enlarged upp...

This species may be seen listed as a member of Nemacheilus or the nomen nudum Noemacheilus in older literature and is sometimes sold as 'red tailed, striped sand loach' or 'red tailed squirrel loach'. Only two other Aborichthys have been described to...

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...

This species isn't common in the trade but occasional specimens may be found among shipments of wild caught fishes from northeast India, and it's sometimes seen on sale as 'pan...

This specie is relatively rare in the aquarium trade and much sought after by enthusiasts as a result. It looks relatively similar to A. sidthimunki but according to the original description by Kottelat and Chu (1987) can be told apart by colour patterning which uniquely consists of a solid da...

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.

An obligate dweller of swiftly-flowing streams and headwaters containing clear, oxygen-saturated water. It often inhabits riffles and runs and is likely to show a preference for shallower zones. Substrates are generally composed of gravel, rocks, boulders or bedrock carpeted with a rich biofilm formed by algae and other micro-organisms. Juveniles are often found in slower-moving stretches with gravel substrate and submerged tree roots. In both cases patches of aquatic plants are only occasionally pres...

An obligate dweller of shallow, fast-flowing, highly-oxygenated headwaters and minor tributaries characterised by stretches of riffles and runs broken up by pools or cascades in some cases. Substrates are normally composed of smaller rocks, sand and gravel with jumbles of boulders, and whil...

Following Grant (2007) this species is included in the B. dario complex of closely-related species within the genus alongside B. striata. They're characterised by body patterning consisting of a base yellow to golden colour with 7-9 blue, green, grey or black body bars usually with thinner, lighter bars between. In some individuals the...

This species is arguably one of the most misunderstood in the hobby since it's wholly unsuitable for smaller aquaria despite its ubiquitous availability. Most retailers sell it without providing what should be considered essential information regarding long-term care and most specimens undoubtedly fail to reach their potential in captivity. The purchase of a group is also a considerable investment given that if properly cared for typical life span is in excess...

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...

G. cornusaccus can be distinguished from congeners by the following combination of characters: secondary rostrum present; incomplete postoral pouch present reduced to pockets located posterior to mouth corners; sublacrymal groove present and visible when viewed laterally; juveniles with thick, cream-coloured bars and blotches on body, adults uniformly-coloured; head dorsum plain; subopercular groove absent; gill slit vertical; snout truncate when viewed dorsally; no scales on abdomen; 55-61 lateral line scale...

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 has probably not been seen in the aquarium trade yet but has been maintained by a few private collectors. It can be distinguished from congeners by the following combination of characters: secondary rostrum present; complete postoral pouch present; body colour brown with up to 9 thin gold stripes; head dorsum dark brown with gold reticulate pattern; subopercular groove absent; gill slit vertical; sublacrymal groove present; sno...

In fact G. farragus and G. ocellatus represent one of 12 pairs of cryptospecies to be found in the genus, differing in subtle aspects of patterning. Cryptospecies are defined as morphologically similar, but reproductively isolated species which in fishes often inhabit adjacent river basins but in some cases occur sympatrically. The phenomenon may be a result of parallel evolution, and is not normally considered to represent an early stage of speciation.

The type locality was a fast-flowing, shallow (50 - 80 cm deep) river between 5-10 metres in width with a substrate of gravel and large rocks. PH was measured at 7.7 and the habitat was unshaded with on...

This species is variable in terms of colour. Large adults may be bright green, orange or barred but are apparently capable of changing from barred to plain in just a few seconds. These different forms have been recorded in the same natural habitats, and some individuals also possess prominent nuptial tubercules covering much of the body.

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. In nature G. monticola occurs sympatrically alongside Garra borneensis, Osteochilus ingeri, Gastromyzon auronigrus, G. cornusaccus, Nemacheilus olivaceus,...

Some individuals do appear very similar to G. farragus, with noticeable spotting on the head, but can usually still be told apart by examining the caudal-fin which tends to contain only a single thick, dark vertical bar in G. farragus whereas in G. ocellatus there are more often two bars, one thick, one thinner. Intermediate forms do exist though meaning identification is sometimes tricky.

It can be distinguished from congeners by the following combination of characters: gill slit angular; presence of subopercular groove, running continuous to origin of pectoral-fin; body black with numerous, small, evenly-spaced light brown spots; head dorsum black with numerous cream spots; pectoral and pelvic fins with cream spots; caudal-fin with iridescen...

This undescribed species has probably not been seen in the aquarium trade yet but is occasionally maintained private collectors. The 'SK' numbering system used here refers to 'South Kalimantan', home to several unidentified members of the genus. Gastromyzon spp. are placed into various 'species groups' (artificial assemblages of species which may or may not be monophyletic) for ease of reference, and based on colour and patterning G. sp. 'SK01' appears similar to members of the G. ridens group which also includes G. crenastus, G. stellatus and G. zebrinus.

Known only from headwaters of the Sungai (river) Amandit, a tributary of the larger Barito basin in the Meratus mountain range, Kalimantan Selatan (South Kalimantan) province, Indonesian Borneo. There currently exist 36 officially-described members of the genus, all of which are endemic to the island with over half restricted to a single river basin or sub-basin.

Gastromyzon spp. are obligate dwellers of swift, shallow streams containing clear, oxygen-saturated water and have been recorded from sea level to 1350 m amsl throughout hill regions of Borneo. They typically inhabit riffles and runs and are often found above or below cascades and waterfalls. Substrates are generally composed of gravel, rocks, boulders or bedrock carpeted with a rich biofilm formed by algae and other micro-organisms.

For long-term success it's best to provide a mature aquarium with a plentiful supply of algae-covered rocks and other surfaces. If unable to grow sufficient algae in the main tank or you have a community containing numerous herbivorous fishes which consume what's available quickly it may be necessary to maintain a separate tank in which to grow algae on rocks and switch them with those in the main tank on a cyclical basis.

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 are typically labelled 'Borneo sucker', 'Hong Kong pleco', 'butterfly loach', etc. regardless of species. It's sometimes misidentified as G. punctulatus, a species not currently traded which possesses yellow finnage and a lighter-coloured, less-intensely spo...

Many loaches from the families Nemacheilidae, Balitoridae and Gastromyzontidae are also suitable but research your choices before purchase in order to be sure as some are excessively aggressive or otherwise competitive. Gastromyzon spp. tend to exist in lo...

Much of the natural diet is likely to be composed of benthic algae plus associated micro-organisms which are rasped from solid surfaces. In captivity it will accept good-quality dried foods and meatier items like live or frozen bloodworm but may suffer internal problems if the diet contains excessive protein. Home-made foods usi...

Current knowledge suggests that H. formosanus is the most widely-distributed and following Chen and Fang (2009) it can be distinguished by the following suite of characters: 3+7 dorsal-fin rays; 10-12 pectoral-fin rays (modally 11) +9-11 (modally 10)...

Most importantly the water must be clean and well-oxygenated so we suggest the use of an over-sized filter as a minimum requirement. Turnover should ideally be 10-15 times per hour so additional powerheads, airstones, etc. should also be employed as necessary. Base substr...

This rarely-traded species is a member of the H. ocellata 'group' of closely-related congeners, an assemblage which currently comprises H. ocellata, H. bilineata, H. confuzona, H. orthogoniata, H. ogilviei and H. parclitella. Following Tan and Ng (2005) these share possession of a colour pattern with reddish tints and dark brown head markings, elongate head, slightly compressed body, 61-77 lateral line scales and dorsal-fin origin placed in advance of pelvic-fin origin.

Most records pertain to the Mekong River basin downstream of the Khone waterfalls in Laos and Cambodia, but this species is also known from some smaller river drainages in southern Thailand, including parts of the Mae Klong system. Type locality is 'Khlong Fit at Ban Kraduk Chang, road 3157 from Trat to borai, about 2-3 kilometers after junction w...

The reason that the paired fins are orientated vertically, as opposed to horizontally in other members of the genus, is unclear but Roberts (1989) suggest it may be an adaptation to this species' ecology, in that it displays a preference for submerged vegetation or woody structures as opposed to rocky environments. They're certainly adapted for a rea...

This species appears is rare in the aquarium hobby with the majority of images both online and in the published literature instead depicting H. confuzona or H. parclitella. All three are members of the H. ocellata 'group' within the genus which currently contains H. ocellata, H. bilineata, H. confuzona, H. orthogoniata, H. ogilviei and H. parclitella. Following Tan and Ng (2005) these share possession of...

The water at the type locality is described as 'clear and fast-flowing over a rocky substratum'. H. parclitella was observed in shallow water among the rocks, and sympatric species included Garra cambodgiensis, Neolissochilus soroides, Poropuntius smedleyi, 'Puntius' binotatus, Homaloptera nebulosa and Amblyceps mangois.

Homalopteroides spp. are specialised micropredators feeding on small crustaceans, insect larvae and other invertebrates. In captivity some sinking dried foods may be accepted but regular meals of live or frozen Daphnia, Artemia, bloodworm, etc., are essential for the maintenance of good health.

The genus Homalopteroides was revalidated by Randall and Page (2012) and is told apart from the related Homaloptera by the following character combination: dorsal-fin origin above pelvic-fin; ≤ 60 lateral-line scales; ≤ 30 predorsal scales; oral morphology consisting of two thin and widely separated rostral barbels on each side of the mouth, thin crescent-shaped lips, the absence of any structure such as a mental pad or lobes between the lateral portions of the lower lip, and a chin that extends anterior to the lateral portions of the lower lip.

Described from close to the village of Ban Khiri Wong, Nakhon Si Thammarat Province, southern (peninsular) Thailand but since recorded throughout much of the country, including the Chao Phraya and Mekong river systems. It's also known from Peninsular Malaysia and parts of the Mekong basin in Laos, Cambodia and Vietnam. Rainboth (1996) considered it 'probably the commonest member of the genus in the Mekong' and in a 2008 study of balitorid habitats in centra...

Tan (2009) redescribed H. stephensoni and it possesses the following unique character set: sub-inferior mouth with thin barbels; five principle, 12-13 secondary pectoral fin rays (usually 12); scaleless belly; pattern of keeled scales on anterior, dorsal portion of body consisting of a single central keel in the posterior third of each scale; 43-50 lateral line...

Described from Kota Tinggi district, Johor state, Peninsular Malaysia but since recorded throughout much of the country as well as parts of the the Mekong river system in Thailand, Laos, Cambodia and Vietnam plus the Kapuas and several other river basins in Kalimantan Barat (West Kalimantan) province, Indonesian Borneo. In the Kahang River, part of the Endau drainage in Jo...

An obligate dweller of swiftly-flowing streams and headwaters containing clear, oxygen-saturated water. It often inhabits riffles and runs and is likely to display a preference for shallower zon...

Type locality is given as 'Lake Meninju, Sumatra, Indonesia', currently known as Danau (lake) Maninjau, but conceivably the fish may have been obtained from the outflowing Antokan river rather on its western side than the lake itself.

Fowler (1940) described this species as the unique member of his new genus Homalopterula on the basis of a single specimen, separated from related genera by the curved shape of the jaws, truncate caudal-fin and scaleless ventral surface.

The differences in pelvic-fin structure and gill openings led Roberts to redefine the genus when describing H. eubranchus, whereas Tan (2006) expressed doubts that the two are even congeneric but was unable to reach a definitive conclusion in the absence of fresh material. At any rate both species can be easily differentiated from Gastromyzon and Neogastromyzon spp. by observing the mo...

It appears that I. hugowolfeldi, I. longicorpus and I. yongdokensis form a biogeographic lineage distinct from I. koreensis and I. pumila, with the former group distributed to the south of the Taebaek and Noryeong moutnain ranges and the latter to the west. This is further evidenced by the fact that the lamina circularis in males of the southern gro...

Among them it's most similar to I. pumila which was initially described as a subspecies but is now considered distinct. The two are most easily-separated by colour pattern; I. koreensis has 10 or...

All Iksookimia species are endemic to Korea, and I. pumila is known only from the Baek River drainage in south-western Korea where its presence has been undermined at some localities due to construction of a dam in the middle reaches of the river during the late 1990s. Type locality is 'Paikchon stream at Sangso-myon, Puan-gun, Chollabuk-do, South Korea'. The reservoir formed by the dam has also be...

Among them it's most similar to I. longicorpus and I. hugowolfeldi but can be distinguished by the following combination of characters: body patterning consisting of 9-13 dark vertical bars along the flanks plus a small dark spot at the base of the upper caudal-fin lobe; no black blotch or markings posterior to the operculum; reduced lamina circularis in males; interorbital width measures 14.7-17.8% o...

This species may not yet have been seen in the aquarium trade outside its native country but has been maintained by a few private collectors. There are currently three species recognised in the genus, all endemic to the Yangtze river drainage, and they're separated from other balitorids by a combination of characters including: relatively long, deeply-forked caudal-fin; roun...

This species differs from congeners in the presence of papillae covering the mouthparts (lips, barbels, and lobes) which are absent in other species. It's also the largest species in the genus and the serrae on the second pectoral fin rays in males form a broa...

We're unaware of this species having yet appeared in the aquarium trade although a few private collectors have experience with it. Among congeners it uniquely possesses a simple suborbital spine and further differs from K. pristes by: smaller adult size (13.5 mm SL vs. 40); presence of a long nasal barbel (vs. absence); anatomy of the modified second pectoral ray in males (6-7 fine, narrow serrae vs. 8-11 pointed, anteriorly-orientated serrae). In K. hipporhynchos the serrae on the second pectoral ray in males form a broad, contiguous blade-like structure but other differences are the same as for K. pristes.

The genus Kottelatlimia was erected by Nalbant (1994) to accommodate K. katik which had previously been assigned to Lepidocephalichthys but differs in various aspects noted earlier by Kottelat and Lim (1992) including: relatively small adult size; scaleless...

Sand-dwelling loaches from the families Botiidae, Cobitidae and Nemacheilidae are also suitable but proper research is essential as some can be excessively territorial or otherwise aggressive. A community based around fishes from its natural waters could include species such as Badis badis,...

This species is not traded often but may occasionally be exported as bycatch among shipments of other species. It can be distinguished from congeners by the following combination of characters: presence of large, exposed scales on top of head; dorsal-fin origin posterior to pelvic-fin origin; moderate to small size (to 29 mm SL); caudal-fin emarginate and with dark reticulations; caudal-fin lobes with dark, elongated spots along upper and lower edges.

This species is not traded often but is occasionally available as bycatch among shipments of other species. It can be told apart from congeners most easily by the prominent, dorsally-orientated, roughly semi-circular lamina circularis in males, a feature unique within the genus. Other distinguishing characters include a combination of: forked caudal-fin; relatively small adult size; dark <-shaped mark at the base of the caudal-fin; a black spot at the base of branched caudal-fin rays 3-5.

Endemic to Sri Lanka with type locality 'shaded pools of mountain streams at Akuressa, Southern Province, Sri Lanka, elevation 500 meters'. It's known from at least five localities, all of which are located in restricted to Sri Lanka's 'wet zone' in the southwest of the island, with records exis...

According to Kottelat (2012) L. manipurensis Arunkumar, 2000, which was described from Moreh, Manipur state, northeastern India, close to the border with Myanmar, is a syonym of L. micropogon. Havird and Page (2010) differentiate the two based on caudal-fin patterning, predorsal length and ver...

This fish has only been traded on a handful of occasions to date. It's been referred to as Lepidocephalichthys cf. hasselti and Lepidocephalus cf. thermalis but appears to be an undescribed member of the former genus. Following a...

This fish may only have been exported for aquaria on a single occasion to date. It exhibits characters reminiscent of both L. alkaia and L. guntea, and has been referred to as L. cf. guntea) but is most likely an undescribed species (Havird, pers. comm.).

This species is not traded often but may be available occasionally bycatch among shipments of other species. It can be told apart from congeners most easily by the following combination of characters: truncate caudal-fin; scaleless patch on top of head; caudal-fin with reticulated patterning, sometimes appearing as a series of thin vertical bars; body reddish brown with darker markings; 3-7 predorsal and 3-6 postdorsal thin, transverse dark bars running across the dorsal surface; relatively deep...

The type locality consisted of remnant ephemeral pools in otherwise dry agricultural land, and many adults were collected from such habitats. Other species present included the congener L. hasselti plus members of Anabas, 'Puntius', Rasbora, Channa, and Hampala.