Potamotrygonidae

Taxobox | name = River stingrays

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image_width = 240px
image_caption = Ocellate river stingray, "Potamotrygon motoro"
regnum = Animalia
phylum = Chordata
classis = Chondrichthyes
subclassis = Elasmobranchii
ordo = Rajiformes
familia = Potamotrygonidae
subdivision_ranks = Genera
subdivision ="Paratrygon" "Plesiotrygon" "Potamotrygon" "Trygon" See text for species.

River stingrays are neotropical freshwater fishes of the Potamotrygonidae family (order Rajiformes).

They are native to eastern South America, living in rivers that drain into the Caribbean, and into the Atlantic as far south as the Río de la Plata in Argentina. Generally, each species is native to a single river basin.

River stingrays are almost circular in shape, and range in size from "Potamotrygon schuhmacheri", which reaches 25 cm in diameter, to the ocellate river stingray, "Potamotrygon motoro", which grows up to a metre in diameter. The dorsal surface is covered with denticles (sharp tooth-like scales).

They have a venomous caudal sting, and are one of the most feared freshwater fishes in the neotropical region, sometimes more feared than piranhas and electric eels. However, they are not dangerous unless stepped on or otherwise threatened.

River stingrays are the only family of batoids to be restricted to fresh water habitats.

pecies

There are nineteen species in four genera:
* Genus "Paratrygon"
** Discus ray, "Paratrygon aiereba" (Müller & Henle, 1841).
* Genus "Plesiotrygon"
** Long-tailed river stingray, "Plesiotrygon iwamae" Rosa, Castello & Thorson, 1987.
* Genus "Potamotrygon"
** Short-tailed river stingray, "Potamotrygon brachyura" (Günther, 1880).
** Vermiculate river stingray, "Potamotrygon castexi" Castello & Yagolkowski, 1969.
** Thorny river stingray, "Potamotrygon constellata" (Vaillant, 1880).
** Largespot river stingray, "Potamotrygon falkneri" Castex & Maciel, 1963.
** Bigtooth river stingray, "Potamotrygon henlei" (Castelnau, 1855).
** Porcupine river stingray, "Potamotrygon hystrix" (Müller & Henle, 1834).
** White-blotched river stingray, "Potamotrygon leopoldi" Castex & Castello, 1970.
** Magdalena river stingray, "Potamotrygon magdalenae" (Duméril, 1865).
** Ocellate river stingray, "Potamotrygon motoro" (Müller & Henle, 1841).
** Red-blotched river stingray, "Potamotrygon ocellata" (Engelhardt, 1912).
** Smooth back river stingray, "Potamotrygon orbignyi" (Günther, 1880).
** Rosette river stingray, "Potamotrygon schroederi" Fernández-Yépez, 1957.
** "Potamotrygon schuhmacheri" Castex, 1964.
** Raspy river stingray, "Potamotrygon scobina" Garman, 1913.
** Parnaiba river stingray, "Potamotrygon signata" Garman, 1913.
** Maracaibo river stingray, "Potamotrygon yepezi" Castex & Castello, 1970.
* Genus "Trygon"
** "Trygon garrapa" Jardine, 1843.

References

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