''Phycocharax rasbora'' is a small

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

freshwater fish Freshwater fish are those that spend some or all of their lives in fresh water, such as rivers and lakes, with a salinity of less than 1.05%. These environments differ from marine conditions in many ways, especially the difference in levels of s ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Characidae Characidae, the characids or characins is a family of freshwater subtropical and tropical fish, belonging to the order Characiformes. The name "characins" is the historical one, but scientists today tend to prefer "characids" to reflect their st ...

and the only member in the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

''Phycocharax''.Ohara, W.M., Mirande, J.M. & Lima, F.C.T.d. (2017)
''Phycocharax rasbora'', a new genus and species of Brazilian tetra (Characiformes: Characidae) from Serra do Cachimbo, rio Tapajós basin.
''PLoS ONE, 12 (2): e0170648.'' It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to the

Brazilian Amazon Brazilian commonly refers to: * Something of, from or relating to Brazil * Brazilian Portuguese, the dialect of the Portuguese language used mostly in Brazil * Brazilians, the people (citizens) of Brazil, or of Brazilian descent Brazilian may also ...

, where only known from the upper Braço Norte River (

Serra do Cachimbo Serra do Cachimbo ( en, Cachimbo Mountains) is a low mountain range in Brazil, in the southern part of the state of Pará, located mostly in the municipalities of Altamira, Itaituba, Jacareacanga, and Novo Progresso. The Serra do Cachimbo compl ...

region), a blackwater

tributary A tributary, or affluent, is a stream or river that flows into a larger stream or main stem (or parent) river or a lake. A tributary does not flow directly into a sea or ocean. Tributaries and the main stem river drain the surrounding drainage ...

in the

Teles Pires The Teles Pires ( pt, Rio São Manuel) is a long river in Brazil. The river flows through the state of Mato Grosso and its lower part marks the border between the states of Mato Grosso and Pará. At its mouth it joins Juruena River and together t ...

basin, itself a part of the

Tapajós The Tapajós ( pt, Rio Tapajós ) is a river in Brazil. It runs through the Amazon Rainforest and is a major tributary of the Amazon River. When combined with the Juruena River, the Tapajós is approximately long. It is one of the largest clearw ...

basin. A

dam A dam is a barrier that stops or restricts the flow of surface water or underground streams. Reservoirs created by dams not only suppress floods but also provide water for activities such as irrigation, human consumption, industrial use, a ...

has been built on the Braço Norte River and while the species is uncommon downstream, it is very abundant in the reservoir above. Its species name refers to the similarity in color and pattern to ''

Trigonostigma ''Trigonostigma'' is a genus of small cyprinid fish found in Southeast Asia. These social, colorful freshwater fish are often kept in aquariums. Species There are currently four recognized species in this genus: * '' Trigonostigma espei'' ( Mei ...

'' rasboras, an unrelated but well-known Asian fish. The mainly reddish males reach up to about in

standard length Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish m ...

, while the duller yellowish females reach up to about .

References

Pristellini Freshwater fish genera Monotypic fish genera Fish described in 2017 {{Characidae-stub