Borneo

Acanthopsoides molobrion is a dwarf horse-faced loach from Borneo, Peninsular Malaysia and southern Thailand. Like others in the genus it lives in flowing, clear-water river channels over sand, fine gravel or mud, and needs a soft, sandy substrate because it spends some of its time completely buried. Several Acanthopsoides in the trade have proven very tricky to identify. This one has 10 to 15 mid-dorsal markings and three bands in the caudal fin.

The horseface loach, Acantopsis dialuzona, is a cobitid loach from Sumatra, Borneo, Java and Peninsular Malaysia, and possibly Thailand. Most literature lists it as A. choirorhynchos, which Kottelat treats as a junior synonym, and few if any fish in the trade come from near the type locality, so they may represent an unidentified species. Juveniles are exported in large numbers but adults are uncommon in the hobby, and it needs soft sand to bury in.

The Asian banjo catfish, Acrochordonichthys rugosus, is an akysid catfish from Java, Sumatra, Borneo, Peninsular Malaysia and southern Thailand. The most commonly encountered member of the genus in the trade, it is still by no means common, and body colouration varies widely even among fish from a single locality. Like its congeners it can secrete a milky substance from the axillary pore when stressed, and this can quickly kill other fishes in the confines of an aquarium.

The silver shark, Balantiocheilos melanopterus, is a large cyprinid from Borneo, Sumatra and possibly Peninsular Malaysia. Also sold as the 'Bala shark', it is among the most commonly encountered ornamental fishes, yet it reaches 300 to 350 mm SL and long-term care is beyond most hobbyists. Wild populations have dwindled or vanished, it has been listed as Endangered by the IUCN since 1996, and fish on sale are almost certainly all commercially bred. It does not occur in Indochina.

Balitoropsis zollingeri is a balitorid loach described from Java and recorded from Sumatra, Borneo, Peninsular Malaysia, Thailand, Laos and Cambodia. An obligate dweller of swiftly flowing streams and headwaters, it lives on riffles and runs over gravel, rocks and bedrock carpeted with biofilm. It needs clean, well-oxygenated water with strong turnover in the aquarium. It lives in aggregations in nature and is less bold when kept singly or in small numbers, so a group of six or more is best.

Barbodes banksi is a cyprinid from Peninsular Malaysia, Singapore and western Borneo, plus the Anambas and Natuna islands of Indonesia. It is tentatively considered distinct from the closely related B. binotatus, differing in a dark, wedge-shaped marking below the dorsal fin in place of a midlateral spot, though the two may be colour forms of a single species. Occasionally exported as bycatch, it lives in habitats from fast hill streams to canals and floodplain ponds.

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 everetti is a cyprinid from Borneo, known from Sarawak and West Kalimantan, where it lives in clear forest streams in the foothills. Uncommon in the hobby, its name has been widely misapplied to the clown barb, B. dunckeri, from Peninsular Malaysia and Singapore. B. everetti is the less colourful of the two, with relatively small dark body markings, a dark blotch at the rear of the dorsal-fin base and 3½ scales above the lateral line.

The false spanner barb, Barbodes kuchingensis, is a cyprinid apparently endemic to western Borneo, from Sarawak into the Kapuas system. It lives mainly in shallow, clear forest streams and is rarely exported, while subadult B. everetti and some populations of B. lateristriga are regularly traded under its name. B. kuchingensis sensu stricto has a prominent row of dark spots along the lateral line and a short streak extending from the upper part of the operculum.

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.

Belodontichthys dinema is a large, open-water predatory catfish from the Malay Peninsula, Sumatra and Borneo that reaches 100 cm TL in the wild. It eats only fish and needs a very large aquarium without tankmates small enough to swallow. Fish exported from Thailand or elsewhere in Indochina under this name are likely to be B. truncatus, the species found in the Mekong and Chao Phraya basins.

The Java combtail, Belontia hasselti, is a labyrinth fish from peninsular Thailand, Peninsular Malaysia, Singapore, Sumatra, Borneo and Java. Also known as the 'Malay combtail', it mostly inhabits acidic forest peat swamps with little water movement. It differs from its only congener, B. signata, in its brownish grey body and the mosaic pattern in its unpaired fins. Growing to 200 mm SL, it will eat very small fishes and is not recommended for the average community aquarium.

Betta albimarginata is a small mouthbrooding labyrinth fish that appears endemic to the Sebuku River drainage in East Kalimantan, Indonesian Borneo. It lives among marginal plant roots and leaf litter in forest streams only 5 to 10 cm deep. With B. channoides it forms the Betta albimarginata group, and the two look very similar: in B. albimarginata the unpaired fins have a broad white distal band and a broad dark submarginal band around a plain red inner portion.

Betta antoni is a mouthbrooding labyrinth fish that appears endemic to the lower Kapuas basin in West Kalimantan, Indonesian Borneo. Known as Betta sp. 'Sanggau' before its description, it belongs to the Betta akarensis group. It inhabits quiet margins and still pools in clear, flowing forest hill streams, and live fish show blue iridescence on the body scales and a distinct black lower lip.

Betta balunga is a mouthbrooding labyrinth fish from Borneo, found from Tawau in Sabah, Malaysia, south to the Sebuku and Mahakam basins in Indonesia. A member of the Betta akarensis group, it has a reddish-orange iris in life. In the Sebuku it lives in very shallow forest streams among roots and leaf litter, and in the Mahakam basin in sluggish blackwater streams among submerged marginal vegetation.

The snakehead betta, Betta channoides, is a small mouthbrooding labyrinth fish from the Mahakam basin in East Kalimantan, Indonesian Borneo. It inhabits shallow forest streams with brownish, acidic water, among leaf litter and marginal plant roots. With the very similar B. albimarginata it forms the Betta albimarginata group, and displaying males are scarlet, with an almost entirely red dorsal fin edged by a thin white band.

Betta dimidiata is a small mouthbrooding labyrinth fish that appears endemic to the upper Kapuas drainage in West Kalimantan, Indonesian Borneo. It is often confused in the trade with B. krataios, formerly B. sp. 'Kapuas', but the caudal fin separates them: rounded in B. krataios, spade-shaped and more extended in adult B. dimidiata. It inhabits shaded forest swamp streams and pools, some only a few centimetres deep.

Betta edithae is a paternal mouthbrooding labyrinth fish from Indonesia, recorded across Kalimantan, southern Sumatra, Bangka, Belitung and Bintan. The only member of the B. edithae group, it is separated from all other Betta spp. by its opaque or translucent branchiostegal membrane and posterior opercle. Fish from Bintan differ from Bornean specimens in several characters, and it remains unclear whether all populations are conspecific.

Betta enisae is a paternal mouthbrooding labyrinth fish known only from parts of the River Kapuas basin in West Kalimantan, Indonesian Borneo. A member of the B. pugnax complex, whose species are notoriously difficult to tell apart, it has transverse bars in the caudal fin. Populations differ in colour and pattern and are often labelled with collection details such as Putussibau or Sentarum. It inhabits cool, shaded forest streams and swamp pools stained with humic acids.

Betta foerschi is a paternal mouthbrooding labyrinth fish from a handful of localities in Central and West Kalimantan, Indonesian Borneo. It lends its name to the B. foerschi group, whose members have iridescent blue or green unpaired fins and two reddish-yellow bars on the opercle. Fish traded as B. foerschi are often the closely-related B. mandor, and the two can be difficult to tell apart.

Betta gladiator is a large paternal mouthbrooding labyrinth fish presumed endemic to the isolated Maliau basin in Sabah, Malaysian Borneo. A member of the B. unimaculata complex, it grows to 90 mm SL. The type series came from heath forest with acidic water of pH 4.2-4.8, where adults were spaced around a metre apart and usually accompanied by a few juveniles. It has a reputation for aggression.

Betta hendra is a small bubble-nesting labyrinth fish known only from the Sabangau peat swamp forest near Palangkaraya, Central Kalimantan, Borneo. A member of the B. coccina group, it has bright iridescent green flanks and fins where most of its relatives are red. It has been traded as B. sp. 'Sengalang/Palangkayara' and B. sp. 'Sebangua'. The type locality is still, shaded blackwater with a pH around 4.0.

Betta ibanorum is a paternal mouthbrooding labyrinth fish from southern and western Sarawak, Borneo, where it exists in several colour forms. Most known localities are blackwater peat swamps, but it has also been collected from clear streams, roadside ditches and a pool at the top of a waterfall. A member of the B. akarensis group, it is uncommon in the hobby and apparently more often fished for food.

Betta ideii is a large paternal mouthbrooding labyrinth fish from southern South Kalimantan and Pulau Laut, Indonesian Borneo. Traded as B. sp. 'Laut' before its description, it belongs to the B. unimaculata complex and grows to 110 mm SL. It looks very similar to its closest relative B. patoti but lacks dark vertical bars on the flanks, and adult males are much darker.

Betta krataios is a paternal mouthbrooding labyrinth fish that appears endemic to the lower River Kapuas basin in West Kalimantan, Indonesian Borneo. Traded as B. sp. 'Kapuas' before its description, it is sometimes confused with B. dimidiata, the other member of the B. dimidiata group. The two are easily told apart since the caudal fin is rounded in B. krataios and spade-shaped and more extended in B. dimidiata.

Betta lehi is a paternal mouthbrooding labyrinth fish endemic to Borneo, in southwestern Sarawak and the lower River Kapuas basin in West Kalimantan. A member of the B. pugnax complex, it has green iridescent scales on the opercle and body and a light blue iridescent band on the anal fin. It inhabits forest peat swamps, acidic clearwater swamps and associated streams, where the pH can be between 3.0 and 5.5.

The Brunei beauty, Betta macrostoma, is a large paternal mouthbrooding labyrinth fish endemic to Brunei and the northern tip of Sarawak, Borneo. It grows to 100 mm SL, and males are red with a red patch on the opercle and an ocellus in the dorsal fin. It lives in still, shady pools at the top of rainforest waterfalls. Listed as Vulnerable by the IUCN, it has been banned from export by the Sultan of Brunei.

Betta mandor is a paternal mouthbrooding labyrinth fish from near Mandor and Anjungan in the lower Kapuas basin, West Kalimantan, Borneo. Known as B. sp. 'Mandor' or B. sp. 'ninja' before its description, it belongs to the B. foerschi group. Males are black and females brown, with twin red bars on the opercle. It is sometimes traded as B. foerschi, and the two can be difficult to tell apart.

Betta midas is a stout-bodied labyrinth fish from the lower Kapuas basin in West Kalimantan, Indonesian Borneo, and may also occur in western Sarawak. It has been traded as B. anabatoides in the past, and most images of it are labelled as such. It has gold iridescent scales on the opercle, belly and body. The paratype series came from a blackwater river in peat swamp forest with a pH of 4.1.

Betta ocellata is a large paternal mouthbrooding labyrinth fish from Sabah, northeastern Borneo, and the Sebuku River basin in East Kalimantan. A member of the B. unimaculata complex, it grows to 90 mm SL and has a pointed, slightly conical head. It has been collected from clear flowing streams, elevated headwater pools, turbid forest streams, ox-bow lakes and ponds in oil palm plantations.

Betta patoti is a large paternal mouthbrooding labyrinth fish from East Kalimantan, Borneo, described from the Mangar River near Balikpapan. A member of the B. unimaculata complex, it grows to 100 mm SL and has 10-14 dark vertical bars on the lower body. Colour varies with locality, from blackish-barred fish around Balikpapan to more reddish ones further north.

Betta pinguis is a paternal mouthbrooding labyrinth fish known only from the middle and upper Kapuas watershed in West Kalimantan, Indonesian Borneo. A member of the B. akarensis group, it has a relatively stocky body and dense dark markings on the opercle below the postorbital stripe. The type specimens came from a small, slightly tannin-stained stream in degraded forest, where B. dimidiata and B. enisae also occur.

Betta simorum is a slender bubble-nesting labyrinth fish from Sumatra and the Kapuas River system in West Kalimantan, Borneo, Indonesia. Growing to around 90 mm SL, it inhabits heavily-vegetated forest peat swamps and blackwater streams. It shares the B. bellica group with B. bellica, from which it differs in its slanted head with a concave profile behind the eye. Populations are often labelled by locality, such as Rantau Panjang or Sungai Bengkwan, to preserve pure bloodlines.

Betta sp. 'Antuta/Bulungan' is an undescribed mouthbrooding labyrinth fish from Bulungan Regency in East Kalimantan, northern Indonesian Borneo. It appears to be a member of the B. unimaculata complex, and its habitat is thought to be flowing highland streams. Adult size is unconfirmed but likely to be 90 to 100 mm. Relatively peaceful, it can be kept in a group in a tank of sufficient size with plenty of hiding places.

Betta taeniata is a mouthbrooding labyrinth fish endemic to Borneo, known from southern Sarawak in Malaysia and northern West Kalimantan in Indonesia. It is usually associated with clear, flowing hill streams, where it lives in quiet marginal zones and still pools among leaf litter and gravel. A member of the B. picta group, it has a yellowish body and fins and a blackish head. Populations such as Sri Aman, Serian and Kapuas are often labelled by locality to preserve pure bloodlines.

Betta uberis is a small bubble-nesting labyrinth fish from peat swamp forests in Central and West Kalimantan, Borneo, Indonesia. Most records come from between the lower Arut and Kumai rivers near Pangkalan Bun. Known to aquarists as Betta sp. 'Sukadana' or B. sp. 'Pangkalanbun' before its description, it belongs to the B. coccina group and is named for its high count of 14 to 17 dorsal-fin rays, which also separates it from its nearest neighbour in the group, B. hendra.

Betta unimaculata is a large mouthbrooding labyrinth fish from the upper Kayan and Mahakam river drainages in East Kalimantan, Borneo, Indonesia. Growing to around 115 mm SL, it has been collected from clear, flowing streams, elevated headwater pools and more turbid forest streams. Populations differ in colour and pattern and will hybridise, so they are labelled by locality and should never be kept together. Fish from 'Tawau' once thought to be this species have been described as B. ocellata.

The mosquito rasbora, Boraras brigittae, is a miniature cyprinid that appears to be endemic to southwestern Borneo. It inhabits blackwater streams and pools associated with forest peat swamps, where the water is very soft and acidic. The congener B. urophthalmoides is often traded under its name, but B. brigittae is larger, lacks a distinct dark blotch at the caudal peduncle and has brighter, more uniformly red patterning. Striped males of B. merah have led to speculation that the two are the same species.

Boraras merah is a miniature cyprinid from southern Borneo, described from the Jelai Bila river basin near Sukamara in Central Kalimantan, Indonesia. Sometimes sold as the 'phoenix rasbora', it lacks colour in much of the body, with the red pigmentation concentrated around dark markings that tend to form spots or blotches. Fully-striped males have led to speculation that it is the same species as B. brigittae, though Kottelat (2013) argued for two species.

The bumblebee goby, Brachygobius doriae, is a small goby from western Borneo and the Natuna Islands, described from Sarawak. Among the more frequently traded members of the genus, it is often misidentified as B. nunus or B. xanthozonus and is most easily confused with B. sabanus. It lives in fresh and brackish water in lowland coastal habitats such as mangrove swamps, estuaries and tidal streams. It is best kept in a species-specific set-up.

The Sabanus bumblebee goby, Brachygobius sabanus, is a small goby described from the Kinabatangan district of Sabah, northeastern Borneo. Among the more frequently traded members of the genus, it is easily confused with B. doriae, but the last one or two rays of its first dorsal-fin are colourless and less than half of the pectoral-fin is black. Its full range is unclear, and populations in Singapore are not thought to be natural. It lives in fresh and brackish lowland coastal habitats.

The eyespot rasbora, Brevibora dorsiocellata, is a small cyprinid from southern Thailand, Peninsular Malaysia, Borneo and Sumatra. It is also traded as the 'green-eyed', 'emerald-eyed' or 'hi-spot' rasbora. The common, commercially produced form is plain-coloured with a greenish-blue reflective patch in the eye, while a probably wild-caught form seen from time to time has russet red at the base of the tail. Some Bornean records may refer to B. cheeya.

Carinotetraodon borneensis is a small red-eyed puffer known only from southern Sarawak, Malaysia (Borneo), in the Sarawak, Sadong and Rajang rivers. Uncommon in the hobby, it is sometimes mixed among shipments of C. salivator, which has distinct dark bars on the head and body in both sexes. Males in particular tend to be territorial, but a group can be kept where there is enough cover and space.

The red-tailed redeye puffer, Carinotetraodon irrubesco, is a small freshwater puffer endemic to Indonesia, known from Sumatra and West Kalimantan. Males have a reddish caudal fin and lack the black spot at the dorsal-fin base seen in the other red-eyed puffers, and the eyes bulge clearly above the head. It has been collected only among submerged riparian vegetation of terrestrial origin, in murky brown water.

Carinotetraodon salivator is a small red-eyed puffer known only from Sarawak, Borneo, in the Lupar, Sarawak and Rajang river systems. Sometimes traded as the 'striped redeye puffer' or 'zebra puffer', it has distinct dark bars on the head and body in both sexes, a colour pattern unique within the genus. Unlike most congeners, there is evidence that it prefers flowing water.

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.

The black snakehead, Channa melasoma, is a snakehead from southern Thailand, Peninsular Malaysia, Singapore, Borneo, Sumatra and the Philippines. It can be told apart from the similar C. baramensis, once considered a synonym, by lacking a black spot in the centre of many body scales and a barred caudal fin. In nature it appears to favour clear forest streams with mud and leaf litter, but it has also been recorded from acidic blackwater in peat swamp forest.

The ocellated snakehead, Channa pleurophthalma, is a snakehead native to southeastern Sumatra and the Kapuas and Barito basins of Indonesian Borneo. It lives in streams and mangroves and is among the few snakeheads known to form aggregations throughout its life. Unlike most Channa spp. it is pelagic and needs plenty of swimming room, with a tank of at least 240 x 60 cm recommended for a fish reaching 350 mm SL.

The clown loach, Chromobotia macracanthus, is a large botiid loach native to river systems of Borneo and Sumatra in Indonesia. Widely sold, it is wholly unsuitable for smaller aquaria: a group needs a tank of at least 180 x 60 cm, and a properly kept fish can live for more than twenty years. Bornean and Sumatran populations differ slightly in pattern, and in the Batang Hari, Sumatra, drifting larvae are now collected and grown on for the trade.

Crossocheilus langei is a cyprinid from Borneo, Peninsular Malaysia and Thailand, one of several near-identical fish sold as the Siamese algae eater. The trade name 'Crossocheilus siamensis' used for these fish is not valid. C. langei can be told apart by a dark blotch in front of the anal fin and a lateral line running straight through the dark body stripe.

Crossocheilus nigriloba is a cyprinid endemic to Borneo, known from the Kapuas, Belayan and Mahakam rivers in Indonesian Kalimantan. Rarely seen, it is among the near-identical congeners traded as 'Siamese algae-eater' or 'SAE' but is simple to identify: the lower caudal-fin lobe carries dark pigment suffused with red, which gave rise to the trade name 'penguin flying fox'. The lateral stripe breaks into blotches when the fish are sparring, stressed or sleeping.

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 janthochir is a cyprinid endemic to Borneo, known from West and Central Kalimantan in Indonesia. It inhabits black water streams and rivers associated with ancient forest peat swamps, where the water is very soft and acidic. Red markings in the dorsal and caudal fins plus a dark lateral stripe make it easy to identify. Specialised shops stock it from time to time, and it also turns up as bycatch among wild fish from Kalimantan.

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 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.

Desmopuntius endecanalis is a cyprinid apparently endemic to the Kapuas River basin in West Kalimantan, Borneo, including the Danau Sentarum lakes. A whitish base body colour and 8 (rarely 7) branched anal-fin rays distinguish it from congeners, and its placement in Desmopuntius was only tentative. Its habitat is unconfirmed, but related species are associated with peat swamps and black water streams.

Sometimes traded as the 'boomerang barb' or 'Foersch's fire barb', Desmopuntius foerschi is a cyprinid from East and Central Kalimantan, Borneo. Extra dark blotches between the second, third and fourth vertical bars, and a mark at the rear of the dorsal-fin base, set it apart from other vertically-striped congeners. It probably inhabits peat swamps and associated blackwater streams, and information on its range is scarce.

Normally traded as the 'pentazona' barb, Desmopuntius hexazona is a cyprinid from southern Borneo, eastern Sumatra, Singapore and the Malay Peninsula. It is almost identical to D. pentazona, which has a small dark marking at the rear of the dorsal-fin base that D. hexazona lacks. Older literature may label it 'Puntius johorensis'. In Singapore it is considered highly endangered and is restricted to the Central Catchment nature reserve.

The striped barb, Desmopuntius johorensis, is a cyprinid from southern Thailand, Peninsular Malaysia, Singapore, Sumatra and Borneo. Juveniles have 4 dark vertical bars and develop 5 or 6 broad lateral stripes as they grow, a pattern change shared with D. gemellus and D. trifasciatus. Before Kottelat (1992) it was referred to as Puntius eugrammus, while the name 'Puntius johorensis' was misapplied to D. hexazona. It lives mainly in peat swamps and black water streams.

The five-banded barb, Desmopuntius pentazona, is a cyprinid generally accepted to be endemic to northwestern Borneo, with a type locality in Sarawak. It is rare in the trade, and most fish sold as 'pentazona barb' are the closely-related D. hexazona. The two are almost identical, but D. pentazona has a small dark marking at the rear of the dorsal-fin base that D. hexazona lacks.

The snakeskin barb, Desmopuntius rhomboocellatus, is a cyprinid endemic to southern Kalimantan, the Indonesian portion of Borneo. It has been recorded from several river systems including the Kapuas, Kepayang and Barito. It most often inhabits peat swamps, black water streams and other still waters with submerged plants and dense riparian vegetation.

Desmopuntius trifasciatus is a cyprinid from Borneo, described from the Kapuas basin in West Kalimantan and also known from southern Sarawak. Like D. gemellus and D. johorensis, juveniles have 4 dark vertical bars, and fish over 40 mm have 3 or 4 broad lateral stripes, the central one broadest. It may also be confused with Striuntius lineatus.

Eirmotus insignis is a small cyprinid known only from the Kapuas basin in West Kalimantan, Borneo, and Belitung Island off Sumatra. It inhabits shady, slow-moving rainforest streams and swamps with dense vegetation. One of four similar species in the genus, it is traded alongside E. octozona as the 'false eight-banded barb' and is told apart mainly by the black markings on its dorsal fin.

The flying fox, Epalzeorhynchos kalopterum, is a cyprinid from southern Thailand, Peninsular Malaysia and the Greater Sunda Islands. Fishes sold as 'false flying fox' or 'Siamese flying fox', such as Garra cambodgiensis and Gyrinocheilus aymonieri, are often confused with it, but it has white-edged red and black fins and two pairs of barbels. It grows increasingly territorial with age and can live for over 15 years.

Gastromyzon aeroides is a hillstream loach endemic to northern Borneo, recorded from western Sabah in Malaysia and the Temburong basin in Brunei. The dorsal, caudal and anal fins are blue in life, and the plain brown body separates it from the other two species in the G. punctulatus group. Like its congeners it needs swift, clean, well-oxygenated water.

Gastromyzon cornusaccus is a small hillstream loach known only from the Sungai Kinarom, a river draining Mount Kinabalu in Sabah, Malaysian Borneo. Before its description it was often misidentified as G. danumensis because of its small adult size and secondary rostrum. Juveniles have thick cream bars and blotches, while adults are uniformly coloured. Like its congeners it needs swift, clean, well-oxygenated water.

Gastromyzon ctenocephalus is a hillstream loach from western Borneo, known only from headwaters of the Sarawak and Sambas rivers. One of the more commonly traded members of the genus, it turns up in mixed shipments labelled 'Borneo sucker', 'Hong Kong pleco' or 'butterfly loach'. It is sometimes misidentified as G. punctulatus, which has yellow fins and a lighter, less intensely spotted body.

Gastromyzon extrorsus is a hillstream loach from the Kimanis and Petagas basins, draining the western Crocker Range in Sabah, Malaysian Borneo. The brown body carries up to nine thin gold stripes and the head a gold reticulate pattern. Growing to around 80 mm SL, it lives in swift, shallow streams with clear, oxygen-saturated water, and in aquaria needs clean, well-oxygenated water with strong turnover.

Gastromyzon farragus is a small gastromyzontid loach from swift hill streams in the Sadong River basin of southern Sarawak, Malaysian Borneo. It is dark brown with thin cream bars across the back and a red caudal fin, and is very close to G. ocellatus. One of the more commonly traded members of the genus, it often arrives in mixed shipments labelled 'Borneo sucker' or 'Hong Kong pleco', and needs clean, well-oxygenated water with strong flow.

Gastromyzon introrsus is a hillstream loach known only from the Padas and Labuk basins, draining the eastern Crocker Range in Sabah, Malaysian Borneo. The brown body has up to 12 cream vertical bars, and it grows to around 95 mm SL. It lives in swift, shallow streams with clear, oxygen-saturated water, and in aquaria needs clean, well-oxygenated water with strong turnover.

Gastromyzon lepidogaster is a hillstream loach from northern Borneo and the most widely-distributed member of the genus. It occurs in Sabah, Brunei and East Kalimantan. Colour is variable: large adults may be bright green, orange or barred, and can apparently change from barred to plain in a few seconds. It is occasionally available in the trade, where the orange form is particularly sought after.

Gastromyzon monticola is a hillstream loach from streams draining Mount Kinabalu into Marudu Bay, and the Wariu basin, in Sabah, Malaysian Borneo. It has a spotted back with wavy bars on the flanks and grows to around 85 mm SL. German aquarist Philipp Dickmann attempted to spawn it and published his observations in 2001. Like its congeners it needs swift, clean, well-oxygenated water.

Gastromyzon ocellatus is a small hillstream loach known only from the Sarawak River drainage in southern Sarawak, Malaysian Borneo. One of the more commonly traded members of the genus, it turns up in mixed shipments labelled 'Borneo sucker', 'Hong Kong pleco' or 'butterfly loach'. The dark brown body has cream bars that break up into an ocellus pattern on the flanks, and the caudal fin is red in life.

Gastromyzon scitulus is a hillstream loach endemic to tributaries of the Sungai Sadong basin in southern Sarawak, Malaysian Borneo. One of the more commonly-traded members of the genus, it usually arrives in mixed shipments labelled 'Borneo sucker' or 'Hong Kong pleco' regardless of species. It forms a pair of cryptospecies with the very similar G. ctenocephalus, and intermediate forms of both mean identification can sometimes be tricky.

Gastromyzon sp. 'SK01' is an undescribed hillstream loach known only from the Sungai Jorong in South Kalimantan, Indonesian Borneo. The Jorong is part of the upper Barito drainage. The 'SK' code refers to South Kalimantan, home to several unidentified members of the genus. Based on colour pattern it appears similar to members of the G. ridens group. It has occasionally been maintained by private collectors, and like its congeners it lives in swift, shallow streams with clear, oxygen-saturated water.

Gastromyzon sp. 'SK02' is an undescribed hillstream loach from the Sungai Amandit headwaters in South Kalimantan, Indonesian Borneo. The Amandit is a tributary of the Barito basin in the Meratus mountain range. Based on colour pattern this species appears similar to members of the G. ridens group, and it has occasionally been maintained by private collectors. Like its congeners it needs clean, well-oxygenated water with strong flow.

Gastromyzon sp. 'SK03' is an undescribed hillstream loach from a tributary of the Sungai Riam Kiwa in South Kalimantan, Indonesian Borneo. The Riam Kiwa feeds the Martapura, a major tributary of the Barito. The 'SK' code refers to South Kalimantan, home to several unidentified members of the genus. Based on colour pattern it appears similar to members of the G. ridens group, and it has occasionally been maintained by private collectors.

Gastromyzon stellatus is a hillstream loach from the Sarawak, Sadong and Lupar River drainages in southern Sarawak, Malaysian Borneo. Its dark brown head and body carry many small yellow spots. It forms a pair of cryptospecies with G. zebrinus and is often confused with it, since both show intermediate colour patterns. One of the more commonly-traded members of the genus, it usually arrives in mixed shipments labelled 'Borneo sucker' or 'Hong Kong pleco'.

Gastromyzon viriosus is a hillstream loach known only from the Tatau River drainage in central Sarawak, Malaysian Borneo. A dark brown body with 8-10 complete vertical cream bars and a thin, cream, reticulated pattern on the head identify it. It is occasionally seen in the trade, most often in mixed shipments labelled 'Borneo sucker', 'Hong Kong pleco' or 'butterfly loach' regardless of species.

Gastromyzon zebrinus is a hillstream loach known only from the upper Sambas River in West Kalimantan, Indonesian Borneo. Its black body carries 11-13 thin cream bars on the dorsal surface. It forms a pair of cryptospecies with G. stellatus, separated from it by an outcrop of the Müller range, and intermediate colour patterns mean the two are often confused. It is one of the more commonly-traded members of the genus.

Gymnochanda filamentosa is a small glassfish known from Johor in southern Peninsular Malaysia and the Kapuas system in West Kalimantan, Borneo. Males carry filamentous dorsal and anal-fin rays, and the body is transparent to translucent yellowish-brown in life. It occurs in swampy, acidic waters over silt and peat, and has appeared in the ornamental trade but is evidently delicate and recommended only to experienced aquarists.

The 'freshwater' moray eel, Gymnothorax tile, is a moray from coastal regions of the Indo-West Pacific, from eastern India to the Philippines. Although typically sold as a freshwater fish, this is not strictly the case, and the profile treats a marine salt mix as mandatory. It has small pale spots on a darker head and body, where the congener G. polyuranodon has much larger dark spots on a paler background. Highly piscivorous, it is best kept alone in all but the very largest aquaria.

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.

The saddle-back loach, Homaloptera orthogoniata, is a 'lizard' loach endemic to Borneo, known from rivers in Sarawak and Kalimantan. It was historically said to occur across much of Indochina. It is rare in the hobby, and most images online and in the literature show H. confuzona or H. parclitella. It always has three large, saddle-shaped markings on the back, the third between the dorsal and caudal fins.

Homalopteroides nebulosus is a small hillstream loach described from the Sok River in northern Peninsular Malaysia and since recorded from Borneo. Poorly known in the aquarium hobby, it may never have been exported for the ornamental trade. Its eyes sit in a comparatively raised position on the head, as in H. tweediei, but it has more lateral line scales. Little is known of its habitat, which is presumed to be swiftly-flowing streams and headwaters.

Homalopteroides stephensoni is a hillstream loach from Borneo, recorded from Kalimantan in Indonesia and from Sabah and Sarawak in Malaysia. Poorly known in the aquarium hobby, it may never have been exported for the ornamental trade. Originally described in Homaloptera, it was placed in Balitoropsis by Kottelat (2012), who subsequently followed Randall and Page (2012) in treating it as a Homalopteroides. Like its congeners it inhabits swiftly-flowing, clear, oxygen-saturated streams.

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.

Homalopteroides weberi is a hillstream loach from Sarawak in Malaysian Borneo, described from the Akar River and possibly endemic to the state. Poorly known in the aquarium hobby, it was questioned as a possible synonym of Balitoropsis stephensoni by Kottelat (2012), but Randall and Page consider it distinct. It inhabits swiftly-flowing streams and headwaters with clear, oxygen-saturated water.

Hypergastromyzon humilis is a small hillstream loach known only from the Melawi basin of the Kapuas system in West Kalimantan, Indonesian Borneo. Not traded specifically, it sometimes turns up as bycatch among shipments of wild-collected Gastromyzon. It is told from those by its small mouth without papillae, and from H. eubranchus, the only other species in the genus, by its 7-8 cream-coloured dorsal bars.

Kottelatlimia hipporhynchos is a small cobitid loach known only from Central Kalimantan in Indonesian Borneo. It lives in slow-moving forest streams with clear, tannin-stained water over white sand, where it rests on the substrate or dives into it, so it must be given a soft sandy substrate. The largest member of the genus, it differs from its congeners in having papillae covering the lips, barbels and lobes of the mouth.

Kottelatlimia pristes is a small cobitid loach from Peninsular Malaysia, Sumatra and Borneo, the most widely-distributed member of its genus. It inhabits small, slow-moving forest streams and peat swamps with tannin-stained water, often in piles of leaf litter. It turns up occasionally in the trade, sometimes as bycatch among other species and under names such as 'Sumatran mini royal loach' or Cobitis cf. sumatranus.

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.

The blue sheatfish, Kryptopterus cryptopterus, is a silurid catfish from the Malay Peninsula, Singapore, Sumatra, Borneo and Java. It inhabits flowing rivers and larger streams with turbid water, and is sometimes traded as 'smokey glass catfish'. Populations from Thailand, Cambodia, Laos and Vietnam once considered conspecific are now referred to K. geminus, its closest relative, from which it differs in having a wider head and a shorter snout and anal fin.

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.

The striped glass catfish, Kryptopterus macrocephalus, is a silurid catfish from Thailand, Malaysia, Singapore and the Greater Sunda Islands. A stenotypic inhabitant of peat swamp forests and associated blackwater streams, it is also known as the false, mottled or tawny glass catfish. Striped and mottled colour forms exist that may or may not be conspecific, and the similar K. piperatus has a pale brown body with scattered dark spots.

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.

Labiobarbus ocellatus is a cyprinid from Peninsular Malaysia, Sumatra and Borneo, with a black spot on the shoulder and one on the caudal peduncle. It is occasionally available in the ornamental trade, typically under a name such as 'Bornean eye-spot silver shark' or the invalid scientific name Cirrhinus chinensis. A pelagic species of rivers and some lakes, it moves into seasonally inundated floodplains and forest during the wet season, and grows to 180 mm SL.

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.

Lepidocephalus macrochir is a cobitid loach described from Sumatra and since recorded from Thailand, Peninsular Malaysia, Java and Borneo. It is traded sporadically as the 'pinky loach', 'deep water kuhli loach' and 'Borneo high body cave loach'. Although sometimes said to be a cave loach, Thai collectors report it from deep water, and in aquaria it spends a lot of time buried in soft substrates.

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.

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 saravacensis is a nemacheilid loach from Borneo, recorded from drainages in Sarawak (Malaysia) and West Kalimantan (Indonesia). It inhabits clear, tea-coloured forest streams with low mineral hardness and pH. Rare in the aquarium hobby, it may only have appeared as bycatch, and it carries 13-17 irregular dark blotches along the lateral line with a similar number of saddles across the back.

Nemacheilus selangoricus is a nemacheilid loach ranging from southern Thailand through Peninsular Malaysia and Singapore to western Borneo and Sumatra. It is most common in shallow, flowing forest streams over sand, gravel and detritus. It belongs to the N. selangoricus group and is most similar to N. spiniferus, from which it differs in its 8-12 very regular dark bars on the flanks.

Nemacheilus spiniferus is a nemacheilid loach from Borneo, recorded from Sarawak, Brunei and Kalimantan, plus the Natuna and Anambas islands. It is most common in shallow, flowing forest streams with clear to slightly tannin-stained water. A member of the N. selangoricus group, it is rare in the aquarium hobby and differs from N. selangoricus in its 10-13 irregularly-shaped dark bars.

The Javanese ricefish, Oryzias javanicus, ranges through Peninsular Thailand, Malaysia, Singapore and Indonesia as far east as Lombok and Sulawesi. Typically found in coastal, normally brackish, streams, pools and mangrove swamps, it tolerates a wide salinity range and has also been recorded in fresh water. It is exported on occasion and sometimes referred to as the 'blue-eyed ricefish'.

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.

Traded as 'eel loach', Pangio doriae is a worm-like cobitid loach from Sarawak in Borneo and from Peninsular Malaysia. Some authors have suggested it is synonymous with P. anguillaris, but it can be told apart by a pair of prominent nasal barbels. The Sumatran population once identified as this species was described as P. bitaimac in 2009. It is most commonly available as bycatch among shipments of other fishes.

Pangio malayana is a barred kuhli loach from Peninsular Malaysia, the Batang Hari drainage in Sumatra and the Kapuas system in Indonesian Borneo. It has 10-16 dark saddles on the upper half of the body and a black bar at the base of the caudal-fin, and looks most similar to P. cuneovirgata, which has a truncate caudal-fin. It is most often encountered as bycatch among shipments of similar-looking congeners.

The black kuhli loach, Pangio oblonga, is a plain-bodied cobitid from Java, Sumatra, Borneo, Peninsular Malaysia and Thailand. Among the more readily available Pangio in the hobby, it is also traded as 'Java loach', 'cinnamon loach' and 'chocolate kuhli loach'. The species will probably turn out to be a complex of closely-related taxa, with at least four genetic lineages identified.

Pangio piperata is a slender kuhli loach from Peninsular Malaysia, Riau Province in Sumatra and the Rajang river drainage in Sarawak. Its yellowish-brown body is peppered with small dark spots forming a rough stripe along the lateral line. Some populations of the variable P. shelfordii look similar and the two often occur together, but P. piperata is generally plainer and has fewer vertebrae. It is exported occasionally, most often as bycatch among congeners.

Usually sold as the 'kuhli' loach, Pangio semicincta is a cobitid loach from Peninsular Malaysia, Sumatra and Borneo. It lives in shallow forest streams and swamps, often in black water, and is typically abundant in leaf litter. P. kuhlii itself is currently considered endemic to Java and has possibly never been seen in aquaria, so the common aquarium 'kuhli' is more likely to be this species or an unidentified relative.

Pangio shelfordii is a variably patterned kuhli loach from Peninsular Malaysia, Singapore, Sumatra and Borneo. Its patterning varies within and between populations, and as currently understood the species represents an assemblage containing a number of unidentified taxa. Some Sumatran and Bornean populations resemble P. piperata, which often occurs alongside it. It is exported occasionally, often as bycatch among shipments of congeners.

Parosphromenus allani is a liquorice gourami from Sarawak in Borneo, East Malaysia, to which it appears endemic. Its type description was a hobbyist-magazine announcement with limited diagnostic information, and fish from around Lundu with a different fin pattern, known to aquarists as P. sp. 'Stunggang' or P. sp. 'Lundu', may or may not be the same species. Much of its habitat has been lost and it is considered in grave danger of extinction.

Parosphromenus anjunganensis is a liquorice gourami known only from a handful of localities near Anjungan in Kalimantan Barat, Indonesian Borneo. Males have uniformly reddish-brown dorsal, anal and caudal fins with a thin bluish to whitish margin. A stenotypic inhabitant of peat swamp forests and blackwater streams, it may be highly threatened, since some habitats in its range have been cleared and drained for agriculture.

Parosphromenus linkei is a liquorice gourami from Central Kalimantan province in Indonesian Borneo, described from creeks near Sukamara. Said to be slightly easier to maintain than most congeners, it has been traded as 'moonspot licorice gourami'. Males have one to three black blotches in the midlateral stripe and a lanceolate caudal fin, and populations that differ in colour should be kept apart. It appears in danger of extinction.

Parosphromenus opallios is a liquorice gourami endemic to Central Kalimantan province in Indonesian Borneo, in the Arut and Benipah river systems. It appeared in the trade on a handful of occasions as P. sp. 'Sukamara' before its description, and occurs alongside P. linkei at Sukamara. A stenotypic inhabitant of peat swamp forests and blackwater streams, it appears in danger of extinction.

Parosphromenus ornaticauda is a liquorice gourami from West Kalimantan, Indonesian Borneo, in the Kapuas drainage near Anjungan and the Pawan system. Sometimes sold as 'ornate licorice gourami', it has occasionally appeared in the trade in substantial quantities but is not easy to maintain and is often susceptible to disease post-import. Males are identified by their caudal-fin pattern and the large amount of black in the dorsal and anal fins.

Parosphromenus quindecim is a liquorice gourami known only from the Pawan and Liong river basins in West Kalimantan, Indonesian Borneo. Before description it was traded as P. sp. 'Manis Mata', though that name apparently refers to a place some 100 km from the type locality where the fish do not occur. Said to be slightly easier to maintain than most congeners, it occurs alongside P. ornaticauda at some localities.

Puntigrus anchisporus is a small cyprinid endemic to Borneo, recorded from Kalimantan in Indonesia and much of Sarawak in Malaysia. One of the four-barred species once called the 'Puntius tetrazona group', it has a complete lateral line, a black dorsal fin with a red outer band and red pelvic fins. It occasionally appears in the hobby, but the trade relies largely on commercially-produced 'tiger barbs' of questionable origin.

Puntigrus pulcher is a small cyprinid endemic to the Indonesian part of eastern Borneo, with records from the Kayan and Mahakam rivers. Considered a synonym of P. anchisporus for decades following Alfred (1963), it was revalidated by Kottelat and Tan (2011). It has an incomplete lateral line, an entirely black dorsal fin and black pelvic fins, and occasionally appears in the hobby, though the trade relies largely on commercially-produced 'tiger barbs'.

The lined barb, 'Puntius' lineatus, is a laterally-striped cyprinid from Peninsular Malaysia, Sumatra and Borneo, found mostly in peat swamps. It is most often confused with 'P.' johorensis, the two being the most common of the striped species in the trade, but it has no more than one pair of barbels, lacks vertical bars as a juvenile and grows smaller. Its habitats include black water streams stained brown with humic acids, with pH as low as 3.0 or 4.0.

The silver rasbora, Rasbora argyrotaenia, is a cyprinid from Peninsular Malaysia, Singapore, Sumatra, Java, Borneo and the Palawan islands. One of the larger rasboras at up to 140 mm TL, it is a plain, silvery fish with a faint dark stripe, and fish pictured under this name with a bold black stripe are probably a regional variant of R. daniconius. A DNA barcode study found two mitochondrial lineages under the name, and the species as currently recognised is likely to be split.

Rasbora dusonensis is a cyprinid from Sumatra, Peninsular Malaysia and Borneo, found in larger river channels and peat swamp blackwaters. Its identity was unclear for decades before its redescription by Ng and Kottelat (2013). It is very similar to R. tornieri, which shares the Musi river with it, but has a bright yellow caudal fin with a broad dark margin, against carmine red in R. tornieri. One specimen measured 162 mm SL, although 95 to 105 mm is a more commonly reported adult size.

Rasbora tornieri is a cyprinid from Sumatra, Borneo, Peninsular Malaysia and the Mekong drainage in Cambodia. Its identity was unclear for decades before its redescription by Ng and Kottelat (2013). It is very similar to R. dusonensis, which shares the Musi river with it, but its caudal fin is carmine red, against bright yellow in R. dusonensis. It lives in flowing streams and peat swamp blackwaters alike.

The giant chocolate gourami, Sphaerichthys acrostoma, is a small gourami known only from the Mentaya River drainage in Indonesian Borneo. It is far from common in the hobby and is traded under several other names, including 'sharp-nosed gourami'. Its colour pattern sets it apart from the other members of the genus. A paternal mouthbrooder, it chiefly inhabits peat swamps and associated black water streams.

The chocolate gourami, Sphaerichthys osphromenoides, is a small gourami from Peninsular Malaysia, Sumatra and Borneo. By far the best known member of the genus, it mostly inhabits peat swamps and black water streams where the pH can drop to 3.0 or 4.0. A maternal mouthbrooder, it is slow-moving and easily outcompeted for food by more boisterous tankmates.

The crossband chocolate gourami, Sphaerichthys selatanensis, is a small labyrinth fish from southern Borneo, Indonesia. It probably inhabits peat swamps and associated black water streams, and is only occasionally seen in the hobby, sometimes sold as 'cherry chocolate gourami'. Originally described as a subspecies of S. osphromenoides, it differs in fin-ray counts and an additional light vertical bar on each flank.

Vaillant's chocolate gourami, Sphaerichthys vaillanti, is a labyrinth fish that appears to be endemic to the Kapuas drainage in Indonesian Borneo. It is also traded as the 'samurai gourami', a misleading name since the fish is neither especially combative nor from Japan. Unlike S. osphromenoides and S. selatanensis it is a paternal mouthbrooder, and females carry alternating red and green vertical bars.