Cypriniformes is an order of ray-finned fish, which includes many families and genera of cyprinid fish, such as barbs, gobies, loaches, botias, and minnows. Cypriniformes is an “order-within-an-order”, placed under the superorder Ostariophysi—which is also made up of cyprinid, ostariophysin fishes. The order contains 11-12 families, over 400 genera, and more than 4,250 named species; new species are regularly described, and new genera are recognized frequently. Cyprinids are most diverse in South and Southeast Asia, but are entirely absent from Australia and South America. At 112 years old, the longest-lived cypriniform fish documented is the bigmouth buffalo.
Danionella is a genus of danionin fish found in freshwater habitats in Myanmar and West Bengal, India. It includes some of the smallest fishes.
The blue moon danio is a species of cyprinid fish endemic to Myanmar. First described in 2009, they are found in small forested streams on the western slope of the Arakan Mountains in Rakhine State of south-western Myanmar; these streams are typically reduced to a series of interconnected pools during the dry season. This species has also been imported to Europe as an aquarium fish with the code names “TW02” and “Broken Line”.
Danio is a genus of small freshwater fish in the family Cyprinidae found in South and Southeast Asia, commonly kept in aquaria. They are generally characterised by a pattern of horizontal stripes, rows of spots or vertical bars. Some species have two pairs of long barbels. Species of this genus consume various small aquatic insects, crustaceans and worms.
Danionella translucida is an extremely small species of cyprinid fish endemic to Myanmar. When described, it was considered to be one of the smallest fish. It was collected from the roots of floating aquatic plants in a slow-flowing, shallow stream in the Pegu Division of Myanmar. It was found alongside Danio, Microrasbora, Erethistes, and Oryzias species. Observed in life, D. translucida is almost perfectly transparent except for its eyes. It has a distinctive pattern of melanophores. There are no melanophores on the dorsal surface except on the head over the posterior part of the brain. On the posterior half of the body, there a few melanophores following the horizontal midline. The sides and underside of the abdomen have melanophores. A double row of melanophores is present on the underside of the fish from the isthmus of the gills to the pelvic fins. Eggs in D. translucida has been found to range in size from about 0.3–0.6 mm (0.012–0.024 in) in diameter, with ripe eggs being at least 0.5 mm (0.020 in) in diameter. Females carried anywhere from 3 to 8 or 10 eggs. Compared to the body of the fish, these eggs are relatively large.
Paedocypris is a genus of tiny cyprinid fish found in swamps and streams on the Southeast Asian islands of Borneo, Sumatra and Bintan.
Paedocypris progenetica is a species of tiny cyprinid fish endemic to the Indonesian islands of Sumatra and Bintan where it is found in peat swamps and blackwater streams. It was discovered by Singaporean ichthyologist Heok Hui Tan. He has written a description of the fish along with another species of the same genus called Paedocypris micromegethes.
Channa harcourtbutleri, the Burmese snakehead, is a species of snakehead endemic to Inle Lake and surroundings in Myanmar. Locally called nga ohn-ma, among aquarists it is considered one of the dwarf snakeheads, but no significant import for aquarists is known. It is one of the smaller species of snakehead and has a standard length of up to 19.4 cm (7.6 in). The specific name honors Sir Harcourt Butler, a British governor in the region.
The Indian flying barb, historically flying barb, is one of the species known in the group flying barbs owing to their extremely long barbels. It was discovered as long ago as 1822 by Hamilton. However, it is rarely seen in aquaria. It is found in Myanmar, Nepal, Pakistan, Sri Lanka and India, it is found in many of the same localities as Danio rerio and Danio dangila, an example being the Jorai Rivulet, a tributary of the Sankosh river in Coochbehar district, West Bengal, India. The rare fish Borellius spp. is locally named "Boirali maach". In Nepalese Terai it is called Dedhawa.
Danio margaritatus, the celestial pearl danio, often referred to in the aquarium trade as galaxy rasbora or Microrasbora sp. 'Galaxy', is a small cyprinid from Myanmar and Northern Thailand. It has so far been found only in a very small area near Hopong east of Inle Lake, at an elevation of over 1,000 m (3,400 ft). Its habitat is part of the Salween basin, namely the Nam Lang and Nam Pawn Rivers. Discovered in 2006, the species quickly appeared in the aquarium trade, where its small size and bright colours made it an instant hit.
Danio erythromicron, often known as emerald dwarf danio and emerald dwarf rasbora, is a species of cyprinid fish which is endemic to Inle Lake in Myanmar.
The Catarina pupfish was a diminutive species of fish in the family Cyprinodontidae, first described in 1972. It was endemic to a spring in Nuevo León, Mexico. In an attempt of saving the rapidly declining species, some were brought into captivity in the late 1980s and early 1990s, but it proved very difficult to maintain. In 1994 it became extinct in the wild. Gradually the captive populations also perished. The last male died in 2014 and the species became extinct.
Paedocypris micromegethes is a species of cyprinid fish endemic to Sarawak in East Malaysia, where it is found in peat swamps. It is one of the smallest vertebrates in the world, with females reaching a maximum size of 11.6 mm.
The Odessa barb is a species of cyprinid fish known from Central Myanmar, where it is known to occur in an artificial pond above the Anisakan Falls and also from the lower Chindwin River. For many years it has been known to the aquarium hobby, where it has frequently been confused with the less colourful ticto barb, but it was only described scientifically in 2008.
The danionins are a group of small, minnow-type fish belonging to the family Cyprinidae. Species of this group are in the genera clades danio and devario, based on the latest phylo-genetic research by Fang et al in 2009. They are primarily native to the fresh waters of South and Southeast Asia, with fewer species in Africa. Many species are brightly coloured and are available as aquarium fish worldwide. Fishes of the danio clade tend to have horizontal stripes, rows of spots, or vertical bars, and often have long barbels. Species within the devario clade tend to have vertical or horizontal bars, and short, rudimentary barbels, if present at all. All danionins are egg scatterers, and breed in the rainy season in the wild. They are carnivores, living on insects and small crustaceans.
Paedocypris carbunculus is a tiny species of cyprinid fish endemic to peat swamps and blackwater streams in Central Kalimantan, Borneo, Indonesia. It is the most recently described species of the three in the genus Paedocypris and it reaches up to 11.5 mm (0.45 in) in standard length. This shoaling species has been kept and bred for several generations in aquariums.
Cyanogaster noctivaga is a species of characin native to the Rio Negro, Brazil. This species is the only known member of the genus Cyanogaster and its scientific name translates as the blue-bellied night wanderer, referring to its unique appearance and nocturnal habits. It was first described in 2013, having been discovered in October 2011 on a scientific expedition organised by the University of São Paulo, Brazil.
Danionella priapus is a species of Danionella endemic to India. It is sexually dimorphic and, like other species in the genus, possesses a skeleton with fewer bones than the closely related zebrafish. However, it has a number of distinguishing features which differentiate it from others in the genus, with the most notable example being the conically projecting genital papilla between the funnel-shaped pelvic fins of males.
Red dwarf rasbora is a species of cyprinid found endemic to Lake Inle in Shan State in Myanmar. It belongs to the genus Microrasbora, which contains two small species of danionins.
Danionella cerebrum is a cyprinid fish species reported in 2021 from turbid low altitude streams on the southern and eastern slopes of the Bago Yoma mountain range in Myanmar as well as from an irrigation canal southwest of the town of Hmawbi in Yangon Division. It was previously erroneously identified as Danionella translucida due to the close resemblance and similar geographical distribution of the two species. Adult fish of the species measure only 10–13.5 mm in size and have a brain volume of just 0.6 mm3 which is thus far the smallest known adult vertebrate brain. Danionella cerebrum larvae have been shown to exhibit similarities but also differences in their locomotor activity compared to the zebrafish to which they are evolutionary closely related.
