Vietnam

The giant Chinese bitterling, Acheilognathus macropterus, is a bitterling from China, the Korean peninsula, northern Vietnam and southeastern Russia. It has been introduced to Japan and is considered invasive there. Typical adults are 100 to 150 mm, and it appears in the trade only irregularly. Like all bitterlings it spawns in living unionid mussels, and its wide range suggests it may be a group of closely-related species.

The princess carplet, Amblypharyngodon chulabhornae, is a small cyprinid from Thailand and the Mekong system in Laos, Vietnam and Cambodia. It favours wetlands and marginal zones with little water movement and plenty of aquatic and floating vegetation,. Almost unknown in the hobby, it turns up as occasional bycatch among shipments of other fishes. A very peaceful schooling fish, it should be kept in a group of at least 8 to 10.

Annamia cf. thuathienensis is a hillstream loach described from the Bô River in Thua Thien-Hue Province, central Vietnam. Its description was published in Vietnamese and very little is known about it: some major resources do not list it as valid, and Kottelat (2012) considers it a 'species inquirenda'. Its ecology should be similar to that of A. normani, which lives in riffles and rapids over rocky substrates.

The Vietnamese giraffe loach, Annamia normani, is a hillstream loach from Mekong tributaries in Vietnam, Laos and Cambodia and from coastal Vietnam. An obligate resident of riffles and rapids, it has been traded as the 'Vietnamese lizard loach' and 'Vietnamese Homaloptera'. Adults studied in the Duc My River were specialised grazers of cyanobacteria. Many of its known habitats are threatened by planned hydroelectric projects.

Bagrichthys obscurus is a bagrid catfish from the Chao Phraya, Bang Pakong and Mekong watersheds in Thailand, Cambodia and Vietnam. One of the lancers, named for the extended dorsal spine in several members of the genus, it has a uniformly brown body with no pale stripe or blotches, a small mouth and a relatively short dorsal spine. It inhabits large, turbid rivers with slow flow, and is shy, nocturnal and territorial towards other bottom-dwellers.

Barbodes aurotaeniatus is a small cyprinid from the middle and lower Mekong basin in Laos, Vietnam, Cambodia and Thailand. Uncommon in the aquarium trade, it has a single pair of maxillary barbels, lacking the rostral barbels of other Barbodes, and usually four small vertical black markings on the flanks. It inhabits streams, irrigation canals and ditches, and is apparently very peaceful, best kept in a mixed-sex group of 6 to 10.

The spotted barb, Barbodes binotatus, is a cyprinid ranging from Myanmar and Thailand through the Greater Sunda Islands to the Philippines. So ubiquitous across its range that it's often called simply 'common barb', it occurs from sea level to at least 2000 m in habitats from fast-flowing hill streams to irrigation canals and floodplain ponds. The basic pattern of a dark spot at the dorsal-fin origin and another on the caudal peduncle varies with origin.

Barbodes semifasciolatus, the green or Chinese barb, is a cyprinid from Vietnam, Taiwan, southwestern China and northern Laos. The natural green form is an infrequent find in the trade, but the selectively-bred golden variant, first produced in the 1960s, is farmed in huge numbers. Commercial fish are largely inbred, with reduced fins and other deformities not uncommon. The name 'Puntius schuberti' often given to the golden form is not an official scientific name.

The red-tailed tinfoil barb, Barbonymus altus, is a large cyprinid from Thailand, Laos, Cambodia and Vietnam. One of two species traded as 'tinfoil barb', it is usually sold at 50 to 75 mm with little information on its eventual size, and long-term care is beyond the resources of most hobbyists. Natural fish lack the black stripe along each caudal-fin lobe seen in B. schwanefeldii, and adults have a golden or bronze hue.

The tinfoil barb, Barbonymus schwanefeldii, is a large cyprinid found across much of Southeast Asia, from the Mekong to Borneo and Sumatra. Usually sold at 50 to 75 mm, it grows to 355 mm SL, and tinfoil barbs are among the species most often returned to shops having outgrown their aquarium. Selectively-bred 'golden' and 'blushing' strains exist, and the species has also been subjected to artificial dyeing.

Betta prima is a paternal mouthbrooding labyrinth fish from south-eastern Thailand and the Mekong basin in Cambodia and Laos. Before its description it was widely misidentified as B. pugnax or B. taeniata, and not all authors place it in the B. pugnax complex. It inhabits clear-water forest swamps and streams that can be still or swift, sheltering among marginal roots, leaf litter and vegetation.

Betta siamorientalis is a small bubble-nesting labyrinth fish from eastern Thailand, western Cambodia and Vietnam. It lives among submerged vegetation in marshes, flooded fields and rice paddies. Before its description in 2012 it was considered a colour form of B. imbellis known as 'black imbellis', and it has also been confused with B. splendens, but DNA analysis showed it to be distinct. Males have a dark brown to black body and a black opercle with two reddish vertical bars.

Boraras urophthalmoides is a miniature cyprinid from southern and central Thailand, Cambodia and Vietnam, including the moats of Angkor Wat. It inhabits shallow, clear, vegetated swamps, marshes, floodplains and rice paddies. Some populations develop an orange-red stripe that leads to confusion with B. brigittae, but B. urophthalmoides is smaller, with a distinct round, dark blotch on the caudal peduncle and a long, unbroken lateral stripe. It is sometimes sold as the 'exclamation-point rasbora'.

The crazy fish, Butis butis, is a flathead gudgeon of coastal and brackish waters across the Indo-Pacific, from eastern Africa to Fiji. The most commonly traded member of the genus, it has many other names, including crocodile fish, duckbill sleeper and upside-down sleeper. A nocturnal ambush predator, it often swims upside-down, and it is territorial and not sociable with conspecifics, so is best kept singly.

The redeye puffer, Carinotetraodon lorteti, is a small freshwater puffer from the lower Mekong basin and the Chao Phraya watershed in Indochina. It inhabits slow-moving to standing water in shady forest streams, minor tributaries and floodplains, often among dense vegetation. It tends to bite the fins of tankmates and is territorially aggressive, so is best kept alone, though a group can be kept with enough space and a suitable layout.

The Chinese snakehead, Channa asiatica, is a snakehead native to central and southern China and northern Vietnam. One of several Channa lacking pelvic fins, it is told apart from them by vertical black bars on a brownish body and numerous white spots on the body and fins. It is best kept in a species tank. Pairs build no bubble nest, and both parents defend several thousand floating eggs and the fry.

The dwarf snakehead, Channa gachua, is a snakehead recorded across an enormous range from Iran to Taiwan and Bali. There is significant evidence that C. gachua as currently understood is a complex of similar-looking species in need of taxonomic review. A mouthbrooder bred regularly in captivity, it can share a well-chosen community with peaceful fishes too large to be prey, but populations should not be mixed as some may hybridise.

The forest snakehead, Channa lucius, is a predatory snakehead from Indochina, Peninsular Malaysia and the Greater Sunda Islands. Also referred to as the 'splendid' or 'shiny' snakehead, it occurs on Sumatra, Borneo and Java, grows to 400 mm SL and favours forest swamps and tributaries. Like others in the genus it breathes atmospheric air, and it needs a dimly-lit tank with plenty of cover and a tightly-fitting lid, since Channa spp. are notorious for their ability to escape.

Crossocheilus atrilimes is one of several near-identical cyprinids traded as the Siamese algae eater, native to the Mekong and Chao Phraya drainages. Telling it apart from C. langei and the undescribed C. sp. 'citripinnis' takes a combination of characters, including a black stripe running to the tip of the caudal fin that broadens and pales when the fish spar. A shoaling fish of flowing streams, it needs spotless, well-oxygenated water and a group of six or more.

Usually offered as the reticulated or fishnet flying fox, Crossocheilus reticulatus is a cyprinid from the Chao Phraya and Mekong basins. A silvery body, dark-edged scales and a dark caudal peduncle blotch set it apart from similar congeners. Patterning varies with collection locality, which led to several names now treated as synonyms. A fish of flowing streams, it is best kept in a group of six or more, since weaker individuals can be bullied in smaller numbers.

The beardless barb, Cyclocheilichthys apogon, is a cyprinid ranging from Myanmar to Vietnam and south via Peninsular Malaysia to Borneo and Sumatra. Also sold as 'skinhead barb', it lacks barbels and has a black blotch at the caudal-fin base plus rows of dark spots along the scale rows. It favours slower-moving or still water and grazes the biofilm on submerged roots and branches. Rarely imported in numbers, it most often arrives as bycatch.

Cyclocheilichthys armatus is a cyprinid ranging from the Mekong region through Thailand and Peninsular Malaysia to Borneo, Sumatra and Java. It forages from mid-water to the bottom of rivers in the dry season and is thought to migrate into flooded forest to breed. Rarely imported in numbers and most often arriving as bycatch, it makes a peaceful, unusual addition to larger aquaria in a group of at least six.

Cyclocheilichthys heteronema is a cyprinid ranging from Myanmar east to Vietnam and south to Peninsular Malaysia, Borneo and Sumatra. Its fimbriated barbels, extended downwards while it browses, are unique in the genus. It doesn't appear to be common in nature, with most records from Peninsular Malaysia, and it reaches the trade only as occasional bycatch. Very peaceful but retiring, it is easily outcompeted by boisterous tankmates.

Cyclocheilichthys repasson is a cyprinid with an enormous range, from the Mekong region and Myanmar through Peninsular Malaysia to Borneo and Sumatra. It grows to around 280 mm SL and favours slower-moving or still water, grazing the biofilm on submerged roots and branches. It is not often seen in the hobby. Most populations have a dark caudal peduncle spot, stripes formed by dark markings on the scales, and two pairs of barbels.

The pearl danio, Danio albolineatus, is a small cyprinid recorded from Myanmar and Indochina south to Peninsular Malaysia and Sumatra. Colour and patterning differ between localities, and doubts remain whether it is a single species or a group of closely related fish. Wild examples are rare in the trade, with most produced commercially in South East Asia or eastern Europe, and some of the fish traded are likely to be hybrids with D. roseus.

The silver tiger perch, Datnioides polota, is a tiger perch widely distributed in southeastern Asia, from India and Bangladesh east to Indonesia. Mostly found in brackish habitats such as estuaries, mangroves and coastal lagoons, it has a highly variable colour pattern with up to 7 dark bars. The name D. quadrifasciatus is sometimes applied to it, but that name is a junior homonym and polota takes precedence.

The Mekong tiger perch, Datnioides undecimradiatus, is known only from the middle and lower Mekong basin in Thailand, Laos, Cambodia and Vietnam. An efficient, largely piscivorous predator of large, deep lowland rivers, it is marked with 4 relatively thin dark bars. The names 'Siamese tiger fish' and 'gold datnoid' are sometimes applied to it, but more typically belong to D. pulcher.

The Mekong flying barb, Esomus longimanus, is a cyprinid from the Mekong basin in Thailand, Laos, Cambodia and Vietnam, and the Tonlé Sap system. It favours shallow, slow-moving and standing waters with dense aquatic vegetation, such as ditches, marshes and rice paddies. Like other Esomus it has greatly enlarged pectoral fins and very long maxillary barbels, and it jumps well enough to escape through the tiniest gaps.

The striped flying barb, Esomus metallicus, is a cyprinid found from the Salween basin in Myanmar east across Thailand to Laos and Cambodia. It is abundant over most of this range and moves into rice paddies and other flooded ground at the onset of the wet season, returning to permanent water when the flooding recedes. Its lateral stripe grows more intense towards the tail and ends at the caudal-fin base.

Folifer brevifilis is a large cyprinid from the Mekong, Salween and Ayeyarwady systems of southern China, Myanmar, Thailand, Laos and Vietnam. It has also been recorded from Hainan and Hong Kong. Growing to 300 mm SL, it is unsuitable for the majority of home aquaria and extremely rare in the ornamental trade. It inhabits flowing middle and lower sections of major rivers and may migrate seasonally to spawn.

The false SAE, Garra cambodgiensis, is a cyprinid from the Mekong, Chao Phraya and Mae Klong basins and northern Peninsular Malaysia. It is still traded as Garra taeniata and is often confused with the Crossocheilus species sold as 'Siamese algae eater'. In this species the dark lateral stripe ends at the caudal peduncle, and a sucker formed by the lower lip is present. It inhabits swiftly-flowing headwaters and tributaries.

Garra fasciacauda is a cyprinid native to the Mekong river system in Thailand, Laos, Vietnam and Cambodia, including the Tonlé Sap basin. It has a black submarginal stripe on both caudal lobes and a plain dorsal fin. It inhabits swiftly-flowing water and migrates seasonally, with many fish moving from the Tonlé Sap system to the Khone Falls in the dry season.

The sucking 'loach', Gyrinocheilus aymonieri, is a stream fish from the Mae Klong, Chao Phraya, Mekong and Dong Nai basins in Indochina. Often sold as a loach, or as the 'Indian' or 'Chinese' algae eater, it is neither a loach nor native to either country. It can live for more than 15 years and is largely unsuitable for the general community aquarium. It is farmed in large numbers, including albino, 'golden', 'piebald' and 'short-bodied' forms.

The kissing gourami, Helostoma temminkii, is an anabantoid from southern Indochina and the Malay Archipelago, and the sole member of its family. The widely traded pinkish-white form is a leucistic variant bred for ornamental purposes, and the 'balloon' variety is intentionally disfigured and much shorter-lived. Its often belligerent behaviour, adult size and life span of over 20 years make it unsuitable for most home aquaria. The 'kissing' appears at least in part related to establishing social dominance.

Homalopteroides smithi is a hillstream loach from Thailand, Peninsular Malaysia and parts of the Mekong basin in Laos, Cambodia and Vietnam. Perhaps the best-known member of the genus, it is relatively common in the aquarium hobby, and Rainboth (1996) considered it 'probably the commonest member of the genus in the Mekong'. An obligate dweller of swiftly-flowing streams and headwaters, it needs clean, well-oxygenated water.

Homalopteroides tweediei is a small hillstream loach from Peninsular Malaysia, the Mekong system and West Kalimantan in Indonesian Borneo. It is often confused with the congener H. smithi. Rainboth (1996) found it less likely to occur in riffles or runs than other members of the genus, and it shows a preference for moderately-flowing stretches of clear, oxygen-rich streams among patches of live or dead vegetation.

Hypsibarbus vernayi is a cyprinid widespread in mainland Southeast Asia, from the Mekong basin in southern China to northern Peninsular Malaysia. Very similar to H. wetmorei, it has yellow pectoral, pelvic and anal fins (orange to red in H. wetmorei), so yellow-finned fish sold as H. wetmorei or 'lemon fin barb' appear likely to be this species. It prefers flowing water with abundant riparian vegetation and migrates seasonally.

Kryptopterus bicirrhis is a silurid catfish from much of Southeast Asia, including the Mekong and Chao Phraya and the Greater Sunda Islands. Uncommon in the aquarium trade, its name was widely misapplied to K. vitreolus in older literature, but the two are easily told apart because K. bicirrhis does not have a transparent body in life. It tends to form schools, so four or more should be kept.

Kryptopterus geminus is a silurid catfish from the lower and middle Mekong in Thailand, Laos, Cambodia and Vietnam, and the lower Chao Phraya. Wild populations were formerly considered K. cryptopterus, and it is likely to be traded as that very similar species. It differs in having a narrower head, a longer snout and anal fin and more laterally-placed eyes, and inhabits flowing rivers and larger streams with turbid water.

Kryptopterus limpok is a silurid catfish widely distributed through Southeast Asia, including the Mekong and the Greater Sunda Islands. It can be told from its congeners by an extremely long mental barbel extending beyond the tip of the pectoral fin. It inhabits flowing rivers and larger streams with turbid water, grows to 260 mm and is almost unheard of in the ornamental trade.

Labiobarbus leptocheilus is a large cyprinid widespread in Southeast Asia, from the Mekong and Salween to the Greater Sunda Islands. Different populations vary somewhat in appearance, and it may turn out to represent a group of closely-related species. The Cambodian Mekong population has been considered a distinct species, Labiobarbus lineatus, and that name is widely used in the ornamental trade although it is currently a synonym. It grows to 260 mm SL and needs spotless, well-oxygenated water.

Laubuka siamensis is a cyprinid from the Mekong, the Chao Phraya and Mae Klong in Thailand, and smaller drainages south to Peninsular Malaysia. Long considered synonymous with L. laubuca, it seems likely to be the species behind many of the fish entering the trade under that name. A conspicuous dark stripe, iridescent blue in life, runs uninterrupted along the rear of the body to an oval blotch on the caudal peduncle. It swims in groups at or just below the surface and is an accomplished jumper.

Lepidocephalichthys hasselti is a cobitid loach described from Java and recorded from Myanmar to Vietnam, Peninsular Malaysia, Sumatra and Borneo. Its wide distribution makes it relatively common in the aquarium hobby. Colour and pattern vary with locality and have led to problems with identification, and the flanks usually show a row of dark blotches or a solid stripe with a light, unpigmented stripe above.

Lepidocephalichthys kranos is a cobitid loach from the Chao Phraya system in Thailand and the Mekong in Thailand, Laos and Vietnam. Some private collectors have kept it. Its colour pattern tends to form a mosaic, unlike the irregular spotting of most congeners, and the body deepens steeply behind the snout to give a 'hunched' appearance. It can often be found living with L. hasselti.

The Vietnamese marbled hog-faced loach, Lepidocephalichthys sp. 'LE1', is a cobitid loach from central Vietnam. Unconfirmed reports suggest it is collected in the coastal province of D'Nang. It has been traded only a handful of times and referred to as Lepidocephalichthys cf. hasselti and Lepidocephalus cf. thermalis, but appears to be an undescribed member of the former genus.

Lepidocephalichthys zeppelini is a tiny cobitid loach from the Mekong system in Thailand and Vietnam and the Chao Phraya drainage in central Thailand. Adults reach only 25.8 mm SL, and the lamina circularis of mature males forms a large, finely serrated flange. Many adults at the type locality were collected from remnant ephemeral pools in otherwise dry agricultural land.

Lobocheilos melanotaenia is a grazing cyprinid from the Mekong in Laos, Thailand, Cambodia and Vietnam, plus the Dong Nai, Chao Phraya and Mae Klong. One of the most abundant species in the seasonal cyprinid migrations of the mainstream Mekong, it is available on a sporadic basis. It is told from L. rhabdoura by its deeper body, narrower mouth and a dark area in the dorsal-fin. It can be aggressive at feeding times and is not particularly tolerant of conspecifics.

Lobocheilos rhabdoura is a grazing cyprinid from Indochina, found in the Mekong, Chao Phraya and Mae Klong systems and south to Peninsular Malaysia. One of the most abundant species in the seasonal cyprinid migrations of the mainstream Mekong, it is available on a sporadic basis. It differs from L. melanotaenia in its shallower body, wider mouth and larger snout tubercules. It can be aggressive at feeding times and is not particularly tolerant of conspecifics.

Luciosoma bleekeri is a slender, pike-like cyprinid from the Mekong in Laos, Thailand, Cambodia and Vietnam, and from central and western Thailand. Subadults are traded regularly as 'apollo shark' or 'shark minnow' and it is frequently confused with L. setigerum, which has a series of black spots on the lateral line scales that this species lacks. It needs the largest private aquaria, and feeds mainly on terrestrial insects taken at the surface.

The apollo shark, Luciosoma setigerum, is a slender cyprinid found across much of Southeast Asia, from the Mekong basin to Borneo, Sumatra and Java. Subadults are traded regularly and are frequently confused with L. bleekeri, which lacks the series of black spots on the lateral line scales. A similar fish of unknown origin with no stripe on the front of the body is also common in the trade, listed as L. cf. setigerum. It needs the largest private aquaria.

Macropodus erythropterus is a paradisefish from coastal hill streams of central Vietnam, in Quang Binh and Quang Tri provinces. Occasionally traded, sometimes as 'red-backed paradisefish', it is often misidentified as M. spechti, which lacks red in the dorsal, anal and caudal fins. Whether the two represent the same taxon has been debated. A bubble nester, it is relatively peaceful unless breeding.

The paradise fish, Macropodus opercularis, is a labyrinth fish from China south of the Yangtze, including Taiwan and Hainan, plus Vietnam and Laos. Imported to France in 1869, it was among the very first ornamental fish brought to Europe. Wild examples are uncommon in the hobby since it is farmed extensively, and xanthic, albino, red, blue and stripeless strains exist. Males are territorially aggressive, especially when breeding, and should not be housed together unless the aquarium is very large.

The black paradise fish, Macropodus spechti, is a labyrinth fish from central Vietnam, known with certainty from the Thu Bồn and Hương river systems. Its name is frequently misapplied to the similar-looking M. erythropterus, easily identified by reddish pigmentation in the dorsal, anal and caudal fins. Older literature sometimes refers to it as M. concolor. Relatively peaceful unless breeding, it is kept in pairs.

The fire eel, Mastacembelus erythrotaenia, is a spiny eel recorded from Laos, Vietnam, Cambodia, Thailand, Malaysia and Indonesia. It usually inhabits sluggish lowland waters including floodplains and slow-moving rivers, and is also a food fish in its native countries. In the aquarium it hides away during the day and often buries itself, so it needs a sand substrate, plenty of cover and a close-fitting hood.

Microcobitis misgurnoides is a small cobitid loach from central Vietnam and the Mekong system in eastern Laos, growing to 41 mm SL. It was described in Cobitis and stayed there for over 60 years until Bohlen and Harant (2011) moved it to the new genus Microcobitis. It apparently lives in groups, and a soft, sandy substrate probably suits it best.

Micronemacheilus cruciatus is a small nemacheilid loach that appears to be endemic to the coastal rivers of Vietnam. It is traded under names including 'Vietnamese multi-banded zebra loach' and 'hovering zebra loach', and its colour pattern is a dark lateral stripe with numerous vertical cross-bars. It can be susceptible to swings in water chemistry and should not go into a biologically immature aquarium.

Mystacoleucus obtusirostris is a riverine cyprinid found from Myanmar and southwestern China to Vietnam, Borneo, Sumatra and Java. Referred to as M. marginatus for decades, it is the most widely distributed member of the genus, and populations vary somewhat in colour pattern. It is occasionally marketed as 'Burmese rainbow barb'. A group of six or more is the smallest to consider, and like all Mystacoleucus it has a forward-pointing predorsal spine that can snag in a net.

Nemacheilus pallidus is a nemacheilid loach from the Mae Klong, Chao Phraya and Mekong systems in Thailand, Laos, Cambodia and Vietnam. It inhabits streams and small rivers with clear to turbid water and substrates of mud, sand or small rocks. The similar-looking N. masyae is sometimes traded under this name, but N. pallidus has a deeper body and dark bars and saddles thinner than the light interspaces between them.

Nemacheilus platiceps is a nemacheilid loach native to the Mekong basin in Laos, Thailand, Cambodia and Vietnam, and the Dong Nai system. It has been collected from shallow, slow-moving hill stream pools where leaf litter collects, and from faster-flowing stretches over gravel. It is only occasionally available in the aquarium trade and has 12-16 dark, irregular body bars, usually split vertically.

Opsarius koratensis is a cyprinid of the middle and lower Mekong in Thailand, Laos and Cambodia, and the Chao Phraya, Mae Klong and Dong Nai systems. It apparently inhabits larger, deeper and more turbid rivers than many congeners. Genetic evidence from Tang et al. (2010) suggests it may represent a distinct genus, and it occasionally appears in the ornamental trade.

Traded as 'butterfly barb' or 'mackerel barb', Opsarius pulchellus is a cyprinid from the Chao Phraya and mid-to-lower Mekong basins. It occurs in Thailand, Laos, Cambodia and Vietnam, typically in submontane headwaters and fast-flowing minor rivers and streams. Also sold as 'royal opsarius', it carries 7-10 elongate vertical bars on each flank, and like its congeners is too fast and vigorous a feeder for the general community.

The medaka, Oryzias latipes, is a ricefish from Japan, Korea, Taiwan, eastern China, Laos and Vietnam. Long used as a model organism in genomic and experimental biology, it was the first vertebrate animal to mate in space, in the mid-1990s. The ornamental 'golden' variant is more often seen than the natural form, and a transgenic 'glowing' form is illegal to buy, sell or own within the European Union.

Traded as 'eel loach', Pangio anguillaris is a cobitid loach from Borneo, Sumatra, Peninsular Malaysia and the Chao Phraya and Mekong basins. It has an extremely elongated, worm-like body with 69-71 vertebrae and no nasal barbels, and is most commonly available as bycatch among shipments of other fishes. The species as currently recognised appears to represent a complex of closely-related taxa.

The giant kuhli loach, Pangio myersi, is a barred cobitid loach from the lower Mekong basin in Laos, Cambodia, Vietnam and Thailand. Traded regularly and also known as 'Myer's loach', it has 8-11 very broad dark bars on an orange body. A submarginal dark bar or row of spots on the caudal-fin separates young or undernourished imports from P. kuhlii and P. semicincta. Albino and leucistic forms are also available, though it is unclear whether these occur naturally.

Puntigrus partipentazona is a small cyprinid recorded from numerous river basins in Vietnam, Cambodia, Laos, Thailand and Peninsular Malaysia. It is easily told from congeners because the dark blotch on its dorsal fin extends onto the body. Typically found in heavily vegetated parts of rivers and sluggish streams, it is generally peaceful, though rival males continually battle for position within the group.

Rhinogobius giurinus is a goby found through much of China, plus Taiwan, the Korean Peninsula, Japan and the Red and Pha river basins in Vietnam. It appears to exist in a number of forms that differ in colour pattern, morphology or both, and it is unclear whether all of them are conspecific. Newly-imported wild fish tend to be aggressive towards conspecifics, so unlike most Rhinogobius it is best kept in sexed pairs.

Rhinogobius leavelli is a goby ranging from northeastern Laos through northern Vietnam to the Pearl drainage in Guangxi, southern China. It appears to exist in a number of forms that differ in colour pattern, morphology or both, although those in the aquarium trade all look similar. Fish identified as this species tend to have an orange blotch at the base of the caudal fin and a dark vertical bar at the base of the pectoral fin.

Rhinogobius mekongianus is a goby from the middle and upper Mekong basin in Laos, Vietnam and Thailand. Its name has been misapplied in the aquarium trade to the congener R. chiengmaiensis, and it does not appear to have been on the market itself. It has 7-8 irregular dark markings on the body (vs. 5 in R. chiengmaiensis), and records from the Chao Phraya drainage most likely refer to that species.

Schistura callichromus is a nemacheilid loach recorded only from the Babianjiang River in the Red River basin, Yunnan Province, China. It is expected to occur in Vietnamese waters as well, and Kottelat (2012) amended the spelling of its name to 'callichroma'. Wild specimens have been observed living in social aggregations of up to six in clear, well-oxygenated headwater streams.

Schistura laterivittata is a nemacheilid loach recorded only from the Babianjiang River in the Red River basin, Yunnan Province, China. Most recent authors have treated it as a synonym of S. caudofurca, but this appears to be a case of misidentification: S. caudofurca has a deeply forked caudal-fin and no dark lateral body stripe. It is expected to occur in Vietnamese waters as well.

Sewellia albisuera is a hillstream loach known only from a handful of localities in the Thu Bon river system, Quang Nam province, central Vietnam. It is very rarely traded but resembles S. sp. 'SEW01', from which it differs in its network of irregular dark reticulations (many small light spots in SEW01). It inhabits shallow, fast-flowing, highly-oxygenated headwaters and tributaries, and the type locality is apparently suffering from pollution.

Sewellia elongata is a hillstream loach from the Bolovens plateau in southern Laos, also recorded in the upper Se Kong drainage in central Vietnam. The largest described Sewellia, growing to at least 73 mm SL, it is most similar to S. diardi but has a relatively slender, elongate body. It appeared in the aquarium trade during 2010 and inhabits shallow, fast-flowing, highly-oxygenated headwaters with riffles and runs.

The tiger hillstream loach, Sewellia lineolata, is a gastromyzontid loach from fast-flowing headwaters in Vietnam and on the Mekong in Laos. Three to five dark stripes on the body make it difficult to confuse with any other member of the genus. The water must be clean, fast-flowing and well-oxygenated, and Sewellia species are arguably the easiest of all loaches to breed in aquaria.

The spotted butterfly loach, Sewellia sp. 'SEW01', is a hillstream loach from Quang Nam province in central Vietnam. One of the more readily available members of the genus, it is also called S. sp. 'spotted' or S. sp. 'special' and has many small, light spots on a dark background. It resembles S. albisuera, and it has been suggested the two are the same species, but this does not appear to be the case.

Sewellia sp. 'SEW02' is an undescribed hillstream loach whose trade specimens are thought to originate in Hue province, central Vietnam. It first became available in early 2009 and was initially identified as S. breviventralis, but it does not fully match that species or S. elongata and remains in need of identification. It is sometimes sold as 'butterfly loach', a generic name used for several balitorids.

Sewellia sp. 'SEW03' is an unidentified hillstream loach thought to originate in Hue province, central Vietnam. First available in early 2009 as S. breviventralis, it cannot be that species because there is no discernible gap between the pelvic and anal fins. It is often imported in mixed batches with S. sp. 'SEW02', which it resembles closely, and needs shallow, fast-flowing, highly-oxygenated water.

Sewellia speciosa is a hillstream loach that appears endemic to the Xe Kong river drainage in central Vietnam and southern Laos. It first became available in early 2010 and sometimes appears on trade lists as 'Laos sucker' or 'Laos Sakura sucker'. The spotted body without stripes separates it from the morphologically similar S. lineolata, which is striped, and it inhabits shallow, fast-flowing, highly-oxygenated headwaters.

Sinogastromyzon tonkinensis is a hillstream loach that appears endemic to the lower Red River drainage in southern China and northern Vietnam. It is poorly known in the hobby but appears to have been exported on a handful of occasions. It occurs alongside three congeners, which are most easily separated by the barbels and mouth width, and it dwells in swiftly-flowing streams and headwaters.

The banded tiger loach, Syncrossus helodes, is a botiid loach from the Mekong in Laos, Cambodia, Vietnam and Thailand, and the Chao Phraya. Reaching 250-300 mm, it lives in flowing waters from headwater streams to main channels and migrates into flooded areas in the wet season to feed and spawn. It is sometimes confused with S. hymenophysa but has small dark markings on the lower body, no dark spot in the dorsal fin and 10-12 bars without bluish borders.

Systomus orphoides is a large cyprinid ranging from Myanmar to Vietnam and south through Peninsular Malaysia to Borneo, Sumatra and Java. It mostly inhabits flowing tributaries and large streams, moving onto inundated farmland and forest in the wet season to feed and spawn. Not often available in the trade and usually seen as bycatch, it grows to 250 mm SL, is quite boisterous, and needs more-or-less spotless water.

The White Cloud Mountain minnow, Tanichthys albonubes, is a small cyprinid from Guangdong and Hainan in southern China and from northeastern Vietnam. It appears to have been extirpated from White Cloud Mountain itself and is considered endangered in China, but all the fish on sale are commercially bred. Inbreeding among farm-bred stock has left many genetically weak and prone to disease or deformity, and permanent exposure to warmer conditions is likely to shorten its life.

Tanichthys micagemmae is a small cyprinid from the Ben Hai river system in north central Vietnam. Sold under trade names such as 'Vietnamese minnow', 'cardinal minnow' and 'royal white cloud', it is smaller than T. albonubes, lacks that species' reddish-brown body colour and has reddish ventral and anal fins. At the type locality it was found only in the margins of a fast-flowing, shallow stream where the flow was much reduced.

Tanichthys sp. 'Vietnam' is a small cyprinid known only from Da Nang province in central Vietnam, first collected in 2009. Sold as T. sp. 'lemon' or 'yellow white cloud', it has also been misidentified as T. thacbaensis, a valid species from much further north in Vietnam. Its ventral and anal fins are bright yellow, and it is smaller than T. albonubes and lacks that species' reddish-brown body colour.

The sparkling gourami, Trichopsis pumila, is a small labyrinth fish from the lower Mekong basin and central and southern Thailand. Also known as the pygmy gourami, it has a solid dark midlateral stripe topped by a row of dark blotches, which with its small size separates it from T. schalleri. Both sexes produce audible 'croaking' sounds with a specialised pectoral mechanism, and most traded fish are produced commercially.

Trichopsis schalleri is a croaking gourami from the lower Mekong basin and the Chao Phraya watershed in Thailand, Laos, Cambodia and Vietnam. Sometimes called the Mekong croaking gourami or three-stripe gourami, it is larger than the similar T. pumila, and its upper body stripe varies with mood and sometimes fades entirely. Peaceful unless breeding, it can be kept in a pair or a group.

The croaking gourami, Trichopsis vittata, is a labyrinth fish found through much of Indochina, Peninsular Malaysia and Singapore. The largest of its genus, it produces audible sounds with a specialised pectoral mechanism unique within the Osphronemidae. Wild populations vary in colour pattern, and records from Borneo, Sumatra and Java might refer to a distinct species.

Xenentodon canciloides is a freshwater needlefish from Borneo, Sumatra, Peninsular Malaysia and Thailand, and is considered to occur in the Mekong. Rarely seen in the ornamental trade, it is far less common there than its congener X. cancila, from which it differs in its slender, delicate jaws and smaller size, not exceeding 30 cm TL. A near-exclusive inhabitant of the upper water column, it is surprisingly peaceful with anything too large to swallow and is best kept in numbers of four or more.

The sun loach, Yasuhikotakia eos, is a botiid loach from the middle and lower Mekong in Laos, Cambodia and Thailand, and the Dong Nai in Vietnam. Its yellow to reddish brown body with a metallic sheen and a large dark marking on each side of the caudal peduncle make it difficult to confuse with any congener. It has a reputation for aggression and can be fiercely territorial where space or shelter is limited, so it suits only larger, well-structured aquaria with other sturdy fishes.

The silver loach, Yasuhikotakia lecontei, is a botiid loach from the middle and lower Mekong and the Chao Phraya and Mae Klong drainages of Thailand. Sometimes confused with Y. modesta, it is a slimmer, more elongate fish, usually brownish with a gold/green sheen, and its roundish caudal peduncle markings do not meet on the ventral surface. It forages under cover of dusk and darkness, and SF members report it milder in temperament than Y. eos and Y. morleti.

The redtail loach, Yasuhikotakia modesta, is a botiid loach from the middle and lower Mekong and the Chao Phraya and Mae Klong drainages of Thailand. One of the more commonly encountered botiids in the hobby, it is also sold as 'blue', 'orange-finned' or 'red-finned' botia. Some fish are dyed and sold as 'blueberry' or 'raspberry' loach, and their health is normally compromised by the process. Deeper-bodied than the similar Y. lecontei, it grows to 250 mm and needs an aquarium with a base of at least 150 ∗ 45 cm.

The skunk loach, Yasuhikotakia morleti, is a botiid loach from the middle and lower Mekong and the Chao Phraya and Mae Klong drainages of Thailand. Common in the hobby, where most fish are farmed commercially, it is also sold as 'skunk botia' or 'Hora's loach'. The dark stripe over its dorsal surface separates it from the similar Y. longidorsalis. It can be combative, nipping fins and harassing tankmates, especially when kept in smaller groups.

Acrossocheilus iridescens is a barred cyprinid known from Laos, northern Vietnam, Yunnan province in southwestern China and Hainan Island. Adults carry wide black vertical bars on the flanks, each six to eight scales across, and lack the filament on the dorsal fin seen in its closest relative, A. longipinnis. Some populations are of questionable taxonomic status, and the species sensu stricto may be restricted to Hainan, where the type locality lies.

The climbing perch, Anabas testudineus, is a labyrinth fish found from Pakistan and Sri Lanka east to southern China, Indonesia and Singapore. It lives in almost every kind of lowland water from rice paddies to main river channels, and can cross several hundred metres of land provided it stays moist. Its taxonomy is confused, and additional taxa probably exist. Its size and predatory nature make it unsuitable for the general community.

Bagarius rutilus is a sisorid catfish from the Red River and other drainages of northern Vietnam and Yunnan in southern China, possibly also Laos. Reaching 700 to 1000 mm SL, it is clearly unsuitable for the home aquarium, and small numbers are only occasionally exported. It has orange fins in life. Adults live in fast, turbulent rapids in large river channels and perform spawning migrations when rivers swell between March and June.

The goonch, Bagarius yarrelli, is a very large sisorid catfish recorded from the Indus in Pakistan east through Indochina to Sumatra and Borneo. Also known as the 'giant devil catfish' and 'sand shark', it reaches 1300 to 2000 mm and is fished for food across much of its range. That wide distribution appears doubtful, and Indian and Southeast Asian populations may prove not to be conspecific. It lives among boulders in the fast, turbulent rapids of large rivers.

The schooling bumblebee goby, Brachygobius aggregatus, is a small goby described from the Philippines and recorded from the lower Mekong in Vietnam. The name appears on ornamental trade lists quite often but seems to be routinely misapplied to other species, particularly B. doriae-type fishes. It is very similar to B. kabiliensis, and both are best considered nominal taxa for now since several species might be involved. Small live foods are probably essential.

The Kabili bumblebee goby, Brachygobius kabiliensis, is a tiny goby described from the Kabili River in Sabah, northeastern Borneo. Its reported range is disjunct, with records from Brunei, Singapore and the lower Mekong in Vietnam and Cambodia. The name is often misapplied to B. doriae-type fishes in the trade. It lives in fresh and brackish lowland coastal habitats and prefers harder water than some congeners. It grows to just 15 to 18 mm.

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 giant snakehead, Channa micropeltes, is a predatory fish from Southeast Asia that grows to well over a metre. Juveniles are sold as 'red' or 'redline' snakehead, but it is suitable only for public installations or the very largest private aquaria. Unlike most Channa species it is pelagic and needs plenty of room to swim, and adults become aggressive at sexual maturity.

The royal featherback, Chitala blanci, is a very large notopterid endemic to the Mekong drainage in Laos, Thailand, Vietnam and Cambodia. Also sold as the 'royal knifefish', it reaches 1200 mm SL and arguably has no place in the ornamental hobby, being suitable only for public installations or the very largest private aquaria. Many small dark spots on the front of the body merge into oblique stripes, and it is thought to be threatened by dam construction.

The clown featherback, Chitala ornata, is a large notopterid native to the Mae Klong, Chao Phraya and Mekong river systems of Thailand and Indochina. Also traded as the 'clown knifefish', it has rows of large ocellated spots above the anal-fin base and is regularly misidentified as C. chitala. It grows to 1000 mm SL and arguably has no place in the ornamental hobby, yet it remains popular, with albino and leucistic forms line-bred for the purpose.

Crossocheilus cobitis is a cyprinid ranging from the Mekong drainage in Laos, Vietnam and Thailand south to Sumatra, Borneo and Java. Primarily a lowland species, it lives in the turbid lower reaches of rivers over mud, close to submerged logs and similar objects. Given its wide range it has probably reached the trade as the invalid 'Crossocheilus siamensis', and it is likely to represent a group of similar-looking, closely related species.

The grass carp, Ctenopharyngodon idella, is a large cyprinid native to the Amur River system in eastern Russia and northeastern China. Adults typically reach 800 to 1200 mm, making it a wholly unsuitable aquarium subject, though an albino form is traded. Widely introduced for aquaculture and weed control, it has caused serious damage to natural waters, and unwanted fish should never be released.

Cyclocheilos enoplos is a large cyprinid from the Mekong region and Thailand south through Peninsular Malaysia to Borneo, Sumatra and Java. Growing to around 750 mm SL, it is clearly unsuitable for aquaria and scarce to non-existent in the ornamental trade. In the Mekong it makes long seasonal migrations, and adults move upstream above Khone Falls in what appear to be spawning migrations.

The Siamese tiger perch, Datnioides pulcher, is a large tiger perch from the Mae Klong, Chao Phraya, Mekong and Dong Nai river systems. Wild populations are hypothesised to have declined by more than 90% since the mid-1980s, and it has been locally extinct in Thailand since the 1990s. Highly sought after by aquarists, it usually has 4 broad dark bars, and D. microlepis is sometimes sold as D. pulcher to raise prices.

Garra fuliginosa is a cyprinid from the Mekong basin in Thailand, Laos, Vietnam and Cambodia, and the Chao Phraya and Mae Klong in Thailand. It tends to inhabit swiftly-flowing headwaters and tributaries with clear, oxygen-saturated water. Like other Garra it has a lower lip modified to form a mental adhesive disc for clinging to surfaces. The body is dark with random lighter scales.

The hampala barb, Hampala macrolepidota, is a cyprinid ranging from Myanmar through Thailand to the Mekong, and south to Borneo, Sumatra and Java. Also known as 'jungle perch' or 'sidebar barb', it can grow to over 2 feet and 5 kg and is a powerful, pelagic predator and not an aquarium subject in all but the most extreme circumstances. Prized as a food and sport fish, it has been introduced to numerous water bodies.

Hemibagrus spilopterus is a bagrid catfish from the Mekong and several other river systems in Laos, Vietnam, Cambodia and Thailand. Relatively common in the ornamental trade, it has been widely misidentified as H. nemurus, a Javan species that may never have been exported for aquaria. Given its size of up to 500 mm SL, its aggressive nature and a lifespan of several decades, it shouldn't be considered a home aquarium subject in all but the most exceptional circumstances.

The crystal-eyed catfish, Hemibagrus wyckii, is a bagrid with an enormous distribution across central Indochina and western Indonesia. Juveniles are sometimes available in the aquarium trade, but buying them is strongly discouraged: it reaches 710 mm SL, is aggressively territorial and can live for several decades. Despite the common name, the blue eye is not given as a distinguishing character in any diagnosis we've seen.

The Asian red tailed catfish, Hemibagrus wyckioides, is a bagrid from the Mekong system in China, Laos, Vietnam, Cambodia and Thailand. It also occurs in the Chao Phraya drainage. The largest bagrid in central Indochina, it reaches at least 900–1000 mm and 70–80 kg, and the largest specimen known measured 1300 mm. Juveniles are sometimes sold, but buying them is strongly discouraged given its size, aggression and a lifespan of several decades.

Incisilabeo behri is a large cyprinid native to the Mekong river system in southern China, Laos, Thailand, Vietnam and Cambodia. Growing to 450 to 550 mm, it is patently unsuitable for the home aquarium, though juveniles are available on a relatively regular basis. The only member of its genus, it is separated from Bangana by a conspicuous transverse notch across the top of the head, and migrates seasonally up the Sekong, Sesan and Srepok rivers.

The black shark, Labeo chrysophekadion, is a large cyprinid from Southeast Asia, including the Mekong, Chao Phraya and the Greater Sunda Islands. Also known as the black sharkminnow, it reaches 600 mm and is aggressively territorial towards conspecifics and similarly-shaped fishes. It continues to be sold despite its patent unsuitability for the home aquarium, and an albino form has been selectively bred for the trade.

The red-finned cigar shark, Leptobarbus rubripinna, is a large pelagic cyprinid from the Mekong, Chao Phraya and Mae Klong river systems of Indochina. For decades it was referred to as its congener L. hoevenii, and both are still traded under the same name. A popular sport fish growing to 800 to 1000 mm, it is wholly unsuitable for private aquaria despite being readily available at 100 to 150 mm. It has a broad dark midlateral stripe and orange to red pelvic and anal fins.

The giant sword minnow, Macrochirichthys macrochirus, is a large pelagic cyprinid widespread in Southeast Asia, from the Mekong to Borneo and Sumatra. Growing to 600 to 800 mm and becoming increasingly piscivorous as it grows, it is unsuitable for the majority of private aquaria, although juveniles are traded on occasion. It is thought to have been extirpated from the Chao Phraya, Mae Klong, Lake Songkhla and Java, and the Mekong populations have been drastically reduced.

Mekongina erythrospila is a large cyprinid endemic to the middle and lower Mekong River system in Laos, Thailand, Cambodia and Vietnam. It tends to inhabit medium to large river channels with fast-flowing water and rocky beds. Occasionally in the ornamental trade, it grows to 400 to 450 mm and is unsuitable for most private aquaria. It can be aggressively territorial towards conspecifics and similarly-shaped fishes.

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.

Phalacronotus apogon is a large silurid catfish from much of Southeast Asia, including Thailand, the Mekong basin and the Greater Sunda Islands. It reaches 700 mm and arguably should not be considered a home aquarium subject at all, but juveniles are sometimes sold as 'blue neon sheatfish' or 'metallic cheatfish' without adequate information on long-term care. It is an important food fish across much of its native range.

The Asian arowana, Scleropages formosus, is an osteoglossid from the Mekong system, eastern Thailand, Peninsular Malaysia, Sumatra and Borneo. Highly valued in the aquarium trade since the 1970s and listed on Appendix I of CITES since 1975, it is now extirpated across much of its range. It occurs in several colour forms, such as the 'super red' of the upper Kapuas, and three were described as species in 2003, though the majority view treats all of them as S. formosus pending review.

Amblyrhynchichthys micracanthus is a riverine cyprinid from the Mekong catchment in Laos, Thailand, Cambodia and Vietnam, and the Chao Phraya system. It moves into inundated forest during the wet season, and wild fish feed on periphyton, plankton and benthic algae. Older records of A. truncatus from mainland Indochina all refer to this species, which has a straighter snout profile, a shorter dorsal-fin spine and fewer gill rakers.

The blotched snakehead, Channa maculata, is a snakehead from coastal drainages of southeastern China, including Hong Kong, and northern Vietnam. It is frequently confused with C. argus but has fewer fin rays and lateral line scales and carries 2-3 rounded blotches on the caudal peduncle. An important food fish, it has become established in Japan, Taiwan, the Philippines, Madagascar and Hawaii, and hybrids with C. argus appear to be quite common in aquaculture.

Elopichthys bambusa is a large predatory cyprinid of eastern Asia, from the Amur River in Russia to the Lam drainage in northern Vietnam. Growing to 2 m and 40 kg, it is entirely unsuitable for the home aquarium, though young individuals appear in the ornamental trade on an irregular basis. The only species in its genus, it is an important food fish over much of its range.

Garra imberba is a cyprinid without barbels from the upper Yangtze, Mekong and Red River basins in southern China, and the upper Red in Vietnam. Records from the Salween system result from confusion with the similarly-named G. imberbis. With G. micropulvinus it is placed in the Semilabeoina, for which the name Ageneiogarra has been suggested. It tends to inhabit swiftly-flowing headwaters and tributaries.

Gymnostomus lobatus is a cyprinid from the middle to lower Mekong basin in Laos, Thailand and Cambodia, and the Chao Phraya and Mae Klong in Thailand. It is considered one of the most abundant species in the massive seasonal migrations of cyprinids in the mainstream Mekong, and enters inundated forests in the wet season. The body is relatively slender and plain silver, with no dark marking on the caudal peduncle, and the snout often projects strongly.

The Siamese mud carp, Gymnostomus siamensis, is a cyprinid from the Mekong, Chao Phraya and Mae Klong basins in Laos, Thailand, Cambodia and Vietnam. Common in the Mekong main channel and larger tributaries, it moves into inundated zones to spawn in the wet season and is abundant in the massive seasonal migrations of cyprinids. It has a relatively deep, plain silver body and a large, broad head.

The yellow eyed silver barb, Hypsibarbus pierrei, is a large cyprinid from the middle and lower Mekong basin in Laos, Thailand, Cambodia and Vietnam. It also occurs in the Dong Nai drainage, and migrates seasonally from larger river channels in the dry season to spawning grounds that remain unknown. Reaching at least 300 mm, it is a valued food fish, and most Hypsibarbus species are thought to be in decline because of the damming of rivers and agriculture.

Labeo pierrei is a large cyprinid from the Mekong river system in southern China, Laos, Thailand, Cambodia and Vietnam, and the Dong Nai in Vietnam. It grows to 800 mm and inhabits main river channels and large, deep tributaries. It migrates seasonally, moving upstream into the Sekong, Sesan and Srepok rivers at the onset of the wet season and returning downstream in the dry months.

Metzia formosae is a small cyprinid from northern Taiwan, Hainan, Hong Kong, southern China and northern Vietnam. It is identified by its upturned mouth and a black stripe along the flank from the gill opening to the caudal-fin base. It inhabits slow-moving to still, well-vegetated waters, including streams, rice paddies, ditches and canals. The genus remains unresolved in taxonomic terms.

Metzia lineata is a cyprinid from southern China, Hainan, Hong Kong and the Red River basin of northern Vietnam. Populations from the upper Pearl River and from Vietnam differ from those elsewhere, which suggests several species may be included under the name. It lives in slow-moving to still, well-vegetated waters. It has been introduced to other river systems in China and to northern Laos.