| Danionella | |
|---|---|
 | |
| Danionella priapus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Cypriniformes |
| Family: | Cyprinidae |
| Subfamily: | Danioninae |
| Genus: | Danionella T. R. Roberts, 1986 |
| Type species | |
| Danionella translucida T. R. Roberts, 1986 | |
| Species | |
See text | |
Danionella is a genus of danionin fish found in freshwater habitats in Myanmar and West Bengal, India. It includes some of the smallest fishes.
Four out of Five Described species of Danionella are found in Myanmar. D. translucida is described from the Ayeyarwady River basin, and D. mirifica was described from the Kamaing area in upper Myanmar. [1] Danionella priapus is endemic to India. [2]
When first described, Danionella translucida was the smallest ostariophysan and the smallest adult vertebrate to inhabit fresh water. [3] Its adult size ranges from 10–12 millimetres (.43–.47 in) SL. [3] D. mirifica gets slightly larger, at about 14 mm (.55 in) SL, but is still one of the smallest freshwater fishes. [1] [4]
Danionella species lack scales and barbels, [3] but possess a lateral line. [5]
D. mirifica has a single row of melanophores between the pelvic fins and the tips of the cleithra, and there is a lack of melanophores on the underside of the abdomen. [1]
D. dracula reaches 17 mm in length. It is neotonous, lacking 44 bones that develop late in the related zebrafish Danio rerio. They have teeth made of bone, rather than the true teeth of other fishes, and the males have a pair of boney fangs which may be used during male-male competitions over nesting sites. Britz et al. believe the lineage lost true teeth about 50 Ma. [6]
| Species | Common Name | Image |
|---|---|---|
| Danionella cerebrum Britz, Conway & Rüber, 2021 |  | |
| Danionella dracula Britz, Conway & Rüber, 2009 | Dracula fish | |
| Danionella mirifica Britz, 2003 | ||
| Danionella priapus Britz, 2009 | | |
| Danionella translucida T. R. Roberts, 1986 |  |
Cyprinidae is a family of freshwater fish commonly called the carp or minnow family, including the carps, the true minnows, and their relatives the barbs and barbels, among others. Cyprinidae is the largest and most diverse fish family, and the largest vertebrate animal family overall, with about 3,000 species; only 1,270 of these remain extant, divided into about 200 valid genera. Cyprinids range from about 12 mm (0.5 in) in size to the 3 m (9.8 ft) giant barb. By genus and species count, the family makes up more than two-thirds of the ostariophysian order Cypriniformes. The family name is derived from the Greek word kyprînos.
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.
The ticto barb or twospot barb is a species of subtropical freshwater fish belonging to the family Cyprinidae. It is a native of the upper Mekong, Salwen, Irrawaddy, Meklong and upper Charo Phraya basins in the countries of Nepal, India, Pakistan, Myanmar, Bangladesh, Thailand, and Sri Lanka. It has frequently been confused with the Odessa barb in the aquarium trade, but in that species the male is reddish-orange.
Sundadanio is a genus of cyprinid fishes from freshwater habitats, typically peat swamps and blackwater streams, in Borneo and Sumatra in southeast Asia. At up to 2.3 cm (0.91 in) in standard length they are very small, but still larger than their close relatives Paedocypris. Species of the two genera are often found together.
Dwarf snakehead is a term coined by aquarists to describe a group of Channa snakehead fishes growing to about 25 cm (10 in) maximum. They are found in freshwater habitats in South and Southeast Asia, and southern China.
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, the dwarf goby, 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.
The dracula fish is a species of tropical danionin fish from the cyprinid family. It is a freshwater fish endemic to Myanmar. A close relative is Danio rerio, the zebrafish of aquariums. It is named dracula after its unusual "fangs"; male dracula fish have protruding tooth-like bones stemming from their jawbones. Males have been observed using their fangs to spar with other males.
Microdevario is a small genus of danionin cyprinids. It was recently described to include species previously in the genus Microrasbora. These small freshwater fish are native to Burma (Myanmar) and adjacent parts of Thailand, and reach up to 1.5–2.3 cm (0.6–0.9 in) in length depending on the exact species involved.
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.
The silver hatchet chela is a danionins fish in the family Cyprinidae. Endemic in South Asia, it is found in Pakistan, India, Bangladesh and Myanmar.
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.
Devario fangae is a species of small cyprinid fish endemic to Myanmar.
Fang Fang Kullander, née Fang Fang, was a Swedish-Chinese ichthyologist.
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.