The short-tailed river stingray (''Potamotrygon brachyura'') is a species of river stingray (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 ...

) native to the

Río de la Plata Basin The Río de la Plata basin (, ), more often called the River Plate basin in scholarly writings, sometimes called the Platine basin or Platine region, is the Hydrography, hydrographical area in South America that drains to the Río de la Plata. I ...

in South America.Oddone, M.C., G. Velasco & G. Rincon (2008). Occurrence of freshwater stingrays (Chondrichthyes: Potamotrygonidae) in the Uruguay River and its tributaries, Uruguay, South America. International Journal of Ichthyology 14 (2): 69-76. It is sometimes known as the giant freshwater stingray, but this name is typically used for '' Urogymnus polylepis''. Growing to a disc diameter of about and a weight of , with unconfirmed records of even larger specimens,Fishing World Records
Potamotrygon brachyura.
Retrieved 3 August 2023. the short-tailed river stingray is the largest freshwater species in its family and one of the heaviest strict freshwater fish in South America, only matched by the

arapaima The arapaima, pirarucu, or paiche is any large species of bonytongue in the genus ''Arapaima'' native to the Amazon Basin, Amazon and Essequibo River, Essequibo basins of South America. ''Arapaima'' is the type genus of the subfamily Arapaiminae ...

(''Arapaima'') and piraíba catfish (''Brachyplatystoma filamentosum''). The primary threat to the short-tailed river stingray is fishing for food and as a

game fish Game fish, sport fish or quarry refer to popular fish species pursued by recreational fishing, recreational fishers (typically angling, anglers), and can be freshwater fish, freshwater or saltwater fish. Game fish can be fish as food, eaten aft ...

(if not released), but it is also under pressure from habitat loss and occasionally caught for aquaria.

Description

The short-tailed river stingray is circular in shape and humped in the back.River Monsters, First Edition, Da Capo Press, 2011, p. 165 The species can reach about in disc diameter and in weight, making it the largest freshwater species in the family

. They have a dark pattern on their backs, probably used as camouflage. The ray's tail is very muscular and thick, covered with short spines at the base and a venomous sting at the end.River Monsters, First Edition, Da Capo Press, 2011, p. 162

Distribution

The short-tailed river stingray is found in the

, including the

Paraguay Paraguay, officially the Republic of Paraguay, is a landlocked country in South America. It is bordered by Argentina to the Argentina–Paraguay border, south and southwest, Brazil to the Brazil–Paraguay border, east and northeast, and Boli ...

Paraná Paraná, Paranã or Parana may refer to: Geology * Paraná Basin, a sedimentary basin in South America Places In Argentina *Paraná, Entre Ríos, a city * Paraná Department, a part of Entre Ríos Province In Brazil *Paraná (state), a state ...

and

Uruguay River The Uruguay River ( ; ) is a major river in South America. It flows from north to south and forms parts of the boundaries of Brazil, Argentina and Uruguay, separating some of the Argentine provinces of La Mesopotamia from the other two countr ...

s in the countries of Argentina, Brazil,

and

Uruguay Uruguay, officially the Oriental Republic of 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 the Río de la Plata to the south and the A ...

. It may also range into

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

in the

Pilcomayo River Pilcomayo (in Hispanicized spelling) ( Quechua Pillkumayu or Pillku Mayu, ''pillku'' red, ''mayu'' river, "red river", Guarani Ysyry Araguay ) is a river in central South America. At long, it is the longest western tributary of the Paraguay Riv ...

(a tributary of the Paraguay River), but this remains unconfirmed. In the north it ranges from the upper Paraguay River basin, including the

Pantanal The Pantanal () is a natural region encompassing the world's largest tropical wetland area, and the world's largest Flooded grasslands and savannas, flooded grasslands. It is located mostly within the Brazilian state of Mato Grosso do Sul, but i ...

, and south to the lowermost freshwater sections of the

Río de la Plata The Río de la Plata (; ), also called the River Plate or La Plata River in English, is the estuary formed by the confluence of the Uruguay River and the Paraná River at Punta Gorda, Colonia, Punta Gorda. It empties into the Atlantic Ocean and ...

. Unlike some other freshwater rays, it has not been able to spread to the upper Paraná River basin after the

Itaipu Dam The Itaipu Dam ( ; ; ) is a hydroelectric dam on the Paraná River located on the border between Brazil and Paraguay. It is the third largest hydroelectric dam in the world, and holds the 45th largest reservoir in the world. The name "Itai ...

flooded the

Guaíra Falls The Guairá Falls () or Guaíra Falls () 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 impoundment of the Itaipu Dam reserv ...

, which represented a natural barrier to its range.

Lifestyle

Female short-tailed river stingrays give birth to up to 19 fully formed young stingrays per litter. The pups start off eating plankton and then move on to consume small mollusks, crustaceans, the larvae of aquatic insects, and fish.

References

External links

Species description of ''Potamotrygon brachyura'' at www.shark-references.com
{{Taxonbar, from=Q1642212 brachyura Freshwater fish of Argentina Freshwater stingrays of Brazil Fish of Paraguay Fish of Uruguay Fauna of the Pantanal Fish described in 1880 Taxa named by Albert Günther