- Potamotrygonidae
Taxobox | name = River stingrays
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 (orderRajiformes ).They are native to eastern
South America , living in rivers that drain into theCaribbean , and into theAtlantic as far south as theRío de la Plata inArgentina . 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 theocellate river stingray , "Potamotrygon motoro", which grows up to a metre in diameter. The dorsal surface is covered withdenticle s (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
piranha s andelectric eel s. However, they are not dangerous unless stepped on or otherwise threatened.River stingrays are the only family of
batoid s to be restricted tofresh 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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