Like other stingrays, the fishes of this genus have venomous barbs at the base of their tails, and their stings are dangerous to humans.[2] It is said that the natives of South America fear the stingray more than they do fear the piranha.[3]
Potamotrygon vary considerably in color, pattern and size, with the maximum disc width ranging from 31 cm (1 ft) in P. wallacei to 1.5 m (5 ft) in P. brachyura.[4][5]
In the aquarium
Though freshwater stingray of other genera do appear in the trade, most are from Potamotrygon. They are best kept with a deep, sandy substrate, in which they bury themselves, often with only the eyes visible. They are not territorial with other animals and can be kept in groups, provided a large enough aquarium is provided. They are carnivorous bottom feeders and require strong filtration as they are rather sensitive to water conditions.[2] Many species of stingray have been bred in captivity and males can be determined by the presence of claspers as in other Chondrichthyans.
Species
There are currently more than 30 recognized extant (living) species in this genus:[1]
^ abCarvalho, M.R.d., Rosa, R.S. & Araújo, M.L.G. (2016): A new species of Neotropical freshwater stingray (Chondrichthyes: Potamotrygonidae) from the Rio Negro, Amazonas, Brazil: the smallest species of Potamotrygon. Zootaxa, 4107 (4): 566-586.
^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.
^Rosa, R.S., Carvalho, M.R.d. & Wanderley, C.d.A. (2008): Potamotrygon boesemani (Chondrichthyes: Myliobatiformes: Potamotrygonidae), a new species of Neotropical freshwater stingray from Surinam. Neotropical Ichthyology, 6 (1): 1–8.
^Fontenelle, J.P., Silva, J.P.C.B.d. & Carvalho, M.R.d. (2014): Potamotrygon limai, sp. nov., a new species of freshwater stingray from the upper Madeira River system, Amazon basin (Chondrichthyes: Potamotrygonidae). Zootaxa, 3765 (3): 249–268.
^Silva, J.P.C.B.; T.S. Loboda (2019). "Potamotrygon marquesi, a new species of neotropical freshwater stingray (Potamotrygonidae) from the Brazilian Amazon Basin". Journal of Fish Biology. 95 (2). doi:10.1111/jfb.14050.
^Carvalho, M.R.d. (2016): Potamotrygon rex, a new species of Neotropical freshwater stingray (Chondrichthyes: Potamotrygonidae) from the middle and upper rio Tocantins, Brazil, closely allied to Potamotrygon henlei (Castelnau, 1855). Zootaxa, 4150 (5): 537–565.
^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.
^Chabain, Jules; Pierre-Olivier Antoine; Ali J. Altamirano-Sierra; Laurent Marivaux; François Pujos; Rodolfo Salas Gismondi; Sylvain Adnet (2017). Cenozoic batoids from Contamana (Peruvian Amazonia) with focus on freshwater potamotrygonins and their paleoenvironmental significance. Geobios 50: 389–400. doi:10.1016/j.geobios.2017.10.003