''Potamotrygon falkneri'', the largespot river stingray or reticulated freshwater stingray, is a species of freshwater stingray in the family

Potamotrygonidae River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family (biology), family Potamotrygonidae in the Order (biology), order Myliobatiformes, one of the four orders of Batoidea, batoids, cartilaginous fishes related to ...

from tropical and

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

South America. It is sometimes seen in the

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

trade, but requires a very large tank.

Taxonomy and appearance

This

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 ...

was originally described by

ichthyologists Ichthyology is the branch of zoology devoted to the study of fish, including bony fish (Osteichthyes), cartilaginous fish (Chondrichthyes), and jawless fish (Agnatha). According to FishBase, 33,400 species of fish had been described as of October ...

Castex and Maciel in 1963. This species is densely spotted above, but the exact color and pattern are very variable. One of these types was initially described as a separate species ''P. castexi'' and another as ''P. menchacai''. Intermediates between the various patterns are common, and all represent variants of the species ''P. falkneri''. It reaches a disc width of up to and a total length, including tail, up to . The so-called "tiger stingray" has sometimes been misidentified as ''P. menchacai'' (a

synonym A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...

of ''P. falkneri''), but it is a separate species that only was scientifically described as '' P. tigrina'' in 2011.Carvalho, M.R.d., Sabaj Pérez, M.H. & Lovejoy, N.R. (2011). ''Potamotrygon tigrina'', a new species of freshwater stingray from the upper Amazon basin, closely related to ''Potamotrygon schroederi'' Fernandez-Yépez, 1958 (Chondrichthyes: Potamotrygonidae). ''Zootaxa 2827: 1–30.''

Etymology

The

etymology Etymology ()The New Oxford Dictionary of English (1998) – p. 633 "Etymology /ˌɛtɪˈmɒlədʒi/ the study of the class in words and the way their meanings have changed throughout time". is the study of the history of the Phonological chan ...

of the term ''

Potamotrygon ''Potamotrygon'' is a genus of freshwater stingrays in the family Potamotrygonidae native to the rivers of South America, and sometimes seen in the aquarium trade. Like other stingrays, the fishes of this genus have venomous barbs at the base of ...

'' derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

words potamos, which means 'river', and ''trygon'' which means 'sting ray'. The species name is in honor of British Jesuit Tomas Falkner (1707-1784), (also spelled Thomas Falconer), for his apostolic and scientific work in Argentina in the 18th-century.

Distribution

This species has a

disjunct distribution In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...

with the best-known population found throughout much of the Paraná—

Paraguay River The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in ...

basin in southern Brazil,

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...

and northeastern Argentina. Initially it did not occur in the upper Paraná basin above the

Guaíra Falls Guairá Falls ( es, Saltos del Guairá, pt, Salto das Sete Quedas do Guaíra) were a series of immense waterfalls on the Paraná River along the border between Paraguay and Brazil. The falls ceased to exist in 1982 when they were inundated by the ...

, but these disappeared after the construction of the

Itaipu Dam The Itaipu Dam ( pt, Barragem de Itaipu , es, Represa de Itaipú ) is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. The construction of the dam was first contested by Argentina, but the negotiations ...

, allowing this species (and several others) to spread.Júlio Júnior, Dei Tós, Agostinho, and Pavanelli (2009). A massive invasion of fish species after eliminating a natural barrier in the upper rio Paraná basin. Neotropical Ichthyology 7(4): 709–18. The other main distribution of ''P. falkneri'' is in the upper

Amazon Basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...

: Madre de Díos, Guaporé,

Beni is a Japanese R&B singer, who debuted in 2004 under the Avex Trax label. In 2008, Arashiro left Avex Trax and transferred to Universal Music Japan where she started to perform as simply Beni (stylized as BENI). She was initially best known fo ...

, Marañón and

Solimões River Solimões () is the name often given to upper stretches of the Amazon River in Brazil from its confluence with the Rio Negro upstream to the border of Peru. Geography The Amazon / Solimões river just above the confluence of the Solimões and ...

s in

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

, eastern Peru and western Brazil.

References

External links

{{Taxonbar, from=Q5017015 falkneri Freshwater fish of Argentina Fish of Bolivia Freshwater fish of Brazil Fish of Paraguay Freshwater fish of Peru Fish of Uruguay Fish of the Amazon basin Fauna of the Pantanal Taxa named by Mariano N. Castex Taxa named by Ignacio Maciel Fish described in 1963