Potamotrygonidae

From Wikipedia, the free encyclopedia
Jump to: navigation, search
River stingrays
Pfauenaugen-Stechrochen - Ocellate river stingray - Potamotrygon motoro.jpg
Ocellate river stingray, Potamotrygon motoro
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Order: Myliobatiformes
Family: Potamotrygonidae
Garman, 1877
Genera

Heliotrygon
Paratrygon
Plesiotrygon
Potamotrygon
Styracura

River stingrays or freshwater stingrays are Neotropical freshwater fishes of the Potamotrygonidae family in the order Myliobatiformes, one of the four orders of batoids, cartilaginous fishes related to sharks. River stingrays are found in rivers in South America draining into the Caribbean Sea and the Atlantic Ocean as far south as the River Plate in Argentina (freshwater stingrays in Africa, Asia and Australia are in another family, Dasyatidae). Each river system has its own endemic stingrays. A single marine genus, Styracura, of the tropical West Atlantic and East Pacific are also part of Potamotrygonidae. They are generally brownish, greyish or black, often with a mottled or speckled pattern, have disc widths ranging from 25 to 200 centimetres (0.8–6.6 ft) and venomous tail stingers. There are more than thirty species in five genera.

Distribution and taxonomy[edit]

They are native to northern, central and 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, and the greatest species richness can be found in the Amazon, especially the Rio Negro, Tapajós, and Tocantins basins (each home to 8–10 species).[1]

In 2016, two marine species formerly included in Himantura were found to belong in Potamotrygonidae, and moved to their own genus Styracura.[2][3] These are S. schmardae from the tropical West Atlantic, including the Caribbean, and S. pacifica from the tropical East Pacific, including the Galápagos.[2][3]

Characteristics[edit]

Potamotrygon leopoldi is part of a species complex of blackish river rays with contrasting pale spots found in the Tapajós, Xingu and Tocantins basins[1]

River stingrays are almost circular in shape, and range in size from Plesiotrygon nana, which reaches 25 cm (10 in) in disc width,[4] to the chupare stingray (S. schmardae), which grows up to 2 m (6.6 ft) in disc width.[5] The latter is one of only two marine species in this family (the other is S. pacifica).[2][3] The largest freshwater species in this family is the short-tailed river stingray (P. brachyura), which grows up to about 1.5 m (5 ft) in disc width.[6] The upper surface is covered with denticles (sharp tooth-like scales). Most species are brownish or greyish and often have distinctive spotted or mottled patterns, but a few species are largely blackish with contrasting pale spots.[1][7]

They have a venomous stinger on the tail, and are some of the most feared freshwater fishes in the Neotropical region because of the injuries they cause.[8][9][10] However, they are not dangerous unless stepped on or otherwise threatened.

River stingrays are the only family of batoids mostly restricted to fresh water habitats.[11][12] While there are true freshwater species in the family Dasyatidae, for example Himantura chaophraya, the majority of species in this family are saltwater fish.

Species[edit]

The taxonomy of the river stingrays is complex and undescribed species remain.

Subfamily Styracurinae

The two Styracura (here S. pacifica) are the only members of the family from marine waters[3]

Subfamily Potamotrygoninae

Plesiotrygon (here P. iwamae with part of tail missing) is very long-tailed compared to other genera in the family[1]
Potamotrygon motoro is one of the best-known and most widespread species in the family

References[edit]

  1. ^ a b c d e f Carvalho, M.R.d. (2016): Description of two extraordinary new species of freshwater stingrays of the genus Potamotrygon endemic to the rio Tapajós basin, Brazil (Chondrichthyes: Potamotrygonidae), with notes on other Tapajós stingrays. Zootaxa, 4167 (1): 1–63.
  2. ^ a b c Last, P.R.; Naylor, G.J.; Manjaji-Matsumoto, B.M. (2016). "A revised classification of the family Dasyatidae (Chondrichthyes: Myliobatiformes) based on new morphological and molecular insights". Zootaxa. 4139 (3): 345–368. doi:10.11646/zootaxa.4139.3.2. 
  3. ^ a b c d Carvalho, M.R.d.; Loboda, T.S.; Silva, J.P.C.B.d. (2016). "A new subfamily, Styracurinae, and new genus, Styracura, for Himantura schmardae (Werner, 1904) and Himantura pacifica (Beebe & Tee-Van, 1941) (Chondrichthyes: Myliobatiformes)". Zootaxa. 4075 (3): 201–221. doi:10.11646/zootaxa.4175.3.1. 
  4. ^ De Carvalho, M.R. and M.P. Ragno (2011). An unusual, dwarf species of Neotropical freshwater stingray, Plesiotrygon nana sp. nov., from the upper and mid Amazon basin: the second species of Plesiotrygon (Chondrichthyes: Potamotrygonidae). Papéis Avulsos de Zoologia 51(7): 101-138.
  5. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Himantura schmardae" in FishBase. January 2017 version.
  6. ^ 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.
  7. ^ a b 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.
  8. ^ Froese, Rainer, and Daniel Pauly, eds. (2017). "Potamotrygonidae" in FishBase. January 2017 version.
  9. ^ Froese, Rainer and Pauly, Daniel, eds. (2017). "Potamotrygon schuhmacheri" in FishBase. January 2017 version.
  10. ^ Dawes, J. (2001). Complete Encyclopedia of the Freshwater Aquarium. New York: Firefly Books Ltd. ISBN 1-55297-544-4. 
  11. ^ Compagno, L. J. V. & S. F. Cook (1995) "The exploitation and conservation of freshwater elasmobranchs: status of taxa and prospects for the future". In: The Biology of Freshwater Elasmobranchs. Oetinger, M. I. & Zorzi, G. D. (eds.). Journal of Aquariculture & Aquatic Sciences, 7: 62–90.
  12. ^ Freshwater Stingrays (Potamotrygonidae): status, conservation and management challenges CITES. AC20 Inf. 8.
  13. ^ De Carvalho, M.R.; N.R. Lovejoy (2011). "Morphology and phylogenetic relationships of a remarkable new genus and two new species of Neotropical freshwater stingrays from the Amazon basin (Chondrichthyes: Potamotrygonidae)". Zootaxa (2776): 13–48. 
  14. ^ a b Loboda, T.S.; de Carvalho, M.R. (2013). "Systematic revision of the Potamotrygon motoro (Müller & Henle, 1841) species complex in the Paraná-Paraguay basin, with description of two new ocellated species (Chondrichthyes: Myliobatiformes: Potamotrygonidae)" (PDF). Neotropical Ichthyology. 11 (4): 693–737. doi:10.1590/s1679-62252013000400001. 
  15. ^ Rosa, de Carvalho & Wanderley (2008). "Potamotrygon boesemani (Chondrichthyes: Myliobatiformes: Potamotrygonidae), a new species of Neotropical freshwater stingray from Surinam". Neotropical Ichthyology. 6 (1): 1–8. doi:10.1590/S1679-62252008000100001. 
  16. ^ Fontenelle, J.P., Da Silva, J.P.C.B. & De Carvalho, M.R. (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.
  17. ^ de Carvalho, Perez & Lovejoy (2011). "Potamotyrgon tigrina, a new species of freshwater stingray from the upper Amazon basin, closely related to Potamotrygon schroederi Fernandez-Yepez, 1958 (Chondrichthyes: Potamotrygonidae)". Zootaxa. 2827: 1–30. 
  18. ^ Carvalho, 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.
  • Ross, Richard (1999) Freshwater Stingrays, Aqualog Special,p49
  • Ross, Richard (2000) Freshwater Rays, Aqualog, p140