Potamotrygonidae

Last updated

River stingrays
Pfauenaugen-Stechrochen - Ocellate river stingray - Potamotrygon motoro.jpg
Ocellate river stingray, Potamotrygon motoro
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Clade: Batomorphi
Order: Myliobatiformes
Family: Potamotrygonidae
Garman, 1877
Type species
Potamotrygon histrix
J. P. Müller & Henle, 1841
Genera

Heliotrygon
Paratrygon
Plesiotrygon
Potamotrygon
Styracura

Contents

River stingrays or freshwater stingrays are Neotropical freshwater fishes of the family Potamotrygonidae in the order Myliobatiformes, one of the four orders of batoids, cartilaginous fishes related to sharks. They are found in rivers in tropical and subtropical South America (freshwater stingrays in Africa, Asia and Australia are in another family, Dasyatidae). 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, speckled or spotted pattern, have disc widths ranging from 31 to 200 centimetres (1.0–6.6 ft) and venomous tail stingers. River stingrays feed on a wide range of smaller animals and the females give birth to live young. There are more than 35 species in five genera.

Distribution and habitat

Potamotrygon histrix is one of the most southernly distributed river stingrays, being found in the Rio de la Plata Basin Potamotrygon adventure aquarium2.jpg
Potamotrygon histrix is one of the most southernly distributed river stingrays, being found in the Río de la Plata Basin

They are native to tropical and subtropical 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. A few generalist species are widespread, but most are more restricted and typically native to a single river basin. [1] [2] The greatest species richness can be found in the Amazon, especially the Rio Negro, Tapajós, and Tocantins basins (each home to 8–10 species). [3] The range of several species is limited by waterfalls. [1]

Freshwaters inhabited by members of Potamotrygonidae vary extensively, ranging from lacustrine to fast-flowing rivers, in blackwater, whitewater and clearwater, and on bottoms ranging from sandy to rocky. [1] [2] In at least some species juveniles tend to occur in shallower waters than adults. [1] Most species are strictly freshwater, but a few may range into brackish estuarine habitats in salinities up to at least 12.4‰. [1]

In 2016, two fully marine species formerly included in Himantura were found to belong in Potamotrygonidae, and moved to their own genus Styracura. [4] [5] These are S. schmardae from the tropical West Atlantic, including the Caribbean, and S. pacifica from the tropical East Pacific, including the Galápagos. [4] [5]

Potamotrygonidae are the only family of rays mostly restricted to fresh water habitats. [6] [7] While there are true freshwater species in the family Dasyatidae, for example Urogymnus polylepis , the majority of species in this family are saltwater fish. [8]

Characteristics

Potamotrygon leopoldi is part of a species complex of blackish river rays with contrasting pale spots found in the Tapajós, Xingu and Tocantins basins [3]

River stingrays are almost circular in shape, and range in size from Potamotrygon wallacei , which reaches 31 cm (1.0 ft) in disc width, [9] to the chupare stingray (S. schmardae), which grows up to 2 m (6.6 ft) in disc width. [10] The latter is one of only two marine species in this family (the other is S. pacifica). [4] [5] The largest freshwater species in this family are the discus ray (Paratrygon aiereba) and short-tailed river stingray (Potamotrygon brachyura), which grow up to 1.5–1.6 m (4.9–5.2 ft) in disc width. [8] [11] At up to 220 kg (490 lb), [8] by far the heaviest freshwater member of the family is the short-tailed river stingray, which among South American strict freshwater fish only is matched by the arapaima (Arapaima) and piraíba catfish (Brachyplatystoma filamentosum). [12] In each species in the family Potamotrygonidae, females reach a larger size than the males. [1]

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. [3] [13] Juveniles often differ, in some species greatly, in colour and pattern from the adults. [3]

Behavior

Potamotrygon henlei and its close relatives (e.g., P. leopoldi) mainly feed on snails in the wild, but easily adapt to a more generalized diet in captivity Potamotrygon national aquarium.jpg
Potamotrygon henlei and its close relatives (e.g., P. leopoldi ) mainly feed on snails in the wild, but easily adapt to a more generalized diet in captivity

Feeding

Members of Potamotrygonidae are predators and feed on a wide range of animals such as insects, worms, molluscs, crustaceans and fish (even spiny catfish). [1] Plant material is sometimes found in their stomachs, but is likely ingested by mistake. [1] The exact diet varies with species; some are generalist predators and others are specialists. For example, Potamotrygon leopoldi mainly feeds on freshwater snails and crabs, although captives easily adapt to a generalist diet. [1] [8] The largest species such as Paratrygon are top predators in their habitat. [1] The jaw joints of stingrays are "loose", allowing them to chew their food in a manner similar to mammals. [15] The family includes both species that are diurnal and species that are nocturnal. [1]

Breeding

As in other rays, this Plesiotrygon iwamae is easily identified as male by its claspers, the pair of elongated structures at the base of the tail Plesiotrygon iwamae underside (Buffalo Zoo).jpg
As in other rays, this Plesiotrygon iwamae is easily identified as male by its claspers, the pair of elongated structures at the base of the tail

Like other Elasmobranchs, male freshwater stingrays are easily recognized by their pair of claspers, modifications of the pelvic fins used when mating. Mating occurs in a ventral-to-ventral position and the females give birth to live young. [1] While still in the mother's uterus, the developing embryo feeds on histotroph, a secretion produced by trophonemata glands. [1] [16] [17] Depending on exact species, the gestation period is 3 to 12 months and there are between 1 and 21 young in each litter. [1] [18] The breeding cycle is generally related to flood levels. [16]

Relationship with humans

When buried in the sand, stingrays such as this Potamotrygon motoro are barely visible (eye center-right on photo) and easily stepped on Potamotrygon motoro (Wroclaw zoo).JPG
When buried in the sand, stingrays such as this Potamotrygon motoro are barely visible (eye center-right on photo) and easily stepped on

Sting

Like other stingrays, members of the family Potamotrygonidae have a venomous stinger on the tail (although it is harmless and vestigal or even absent in Heliotrygon ). [8] [19] There are generally one or two stingers, and they are periodically shed and replaced. [20] They are some of the most feared freshwater fishes in the Neotropical region because of the injuries they can cause. [21] [22] [23] In Colombia alone, more than 2,000 injuries are reported per year. [24] Freshwater stingrays are generally non-aggressive, [24] and the stingers are used strictly in self-defense. [25] As a consequence injuries typically occur when bathers step on them (injuries to feet or lower legs) or fishers catch them (injuries to hands or arms). [25] In addition to pain caused by the barbed stinger itself and the venom, bacterial infections of the wounds are common and may account for a greater part of the long-term problems in stinging victims than the actual venom. [25] The stings are typically highly painful and are occasionally fatal to humans, especially people living in rural areas that only seek professional medical help when the symptoms have become severe. [25] In general, relatively little is known about the composites of the venom in freshwater stingrays, but it appears to differ (at least in some species) from that of marine stingrays. [25] There are possibly also significant differences between the venoms of the various Potamotrygonidae species. [26] Due to the potential danger they represent, some locals strongly dislike freshwater stingrays and may kill them on sight. [18] A study at the Butantan Institute, São Paulo, Brazil, revealed that the composition of freshwater stingray venom varies according to sex and age, even between individuals of the same species. Each time the environment changes, the feeding of the stingray changes, leading to changes in the composition of toxins and toxicological effects. There is no specific antidote or treatment for freshwater stingray venom. [27]

Symptomatology

Accidents occur when the rays are stepped on or when the fins are touched, the defensive behavior consists of turning the body, moving the tail and introducing the stinger into the victim. Generally, stingers are inserted into the feet and heels of bathers and the hands of fishermen. Initial symptoms include severe pain, erythema and edema, then necrosis occurs which results in sagging tissue in the affected area and forms a deep ulcer, which develops slowly. Systemic complications include nausea, vomiting, salivation, sweating, respiratory depression, muscle fasciculation and seizures. Once the stinger is torn during penetration into the skin, it can break and cause dentin fragments to be retained in the wound. The stinger can cause laceration, which results in secondary infection, usually caused by Pseudomonas and Staphylococcus . If the stinger reaches internal organs, it can be fatal. [28]

As food

Freshwater stingrays are often caught by hook-and-line and as bycatch in trawls. In the Amazon, Paratrygon and certain Potamotrygon are the most caught species and the first is the most sought. [29] In the Río de la Plata region, the meat of P. brachyura is particularly prized and locally the species is called raya fina (fine ray). [30] Freshwater rays weighing less than 2 kg (4.4 lb) are generally discarded, but have a low survival rate. [29] Their meat is mainly consumed locally, but is also exported to Japan and South Korea. [29] From 2005 to 2010, the reported capture in the Brazilian states of Amazonas and Pará has ranged between 584.5 and 1,104.5 metric tons (575.3–1,087.1 long tons) per year. [29] In contrast, some fishers believe they only can be used for traditional medicine, incorrectly thinking that the meat (not just the tail region around the stinger) is toxic. [31]

In captivity

Potamotrygon jabuti is a valuable species in the aquarium trade, but export of wild-caught individuals from Brazil (as opposed to captive bred) is illegal. Potamotrygon jabuti1.jpg
Potamotrygon jabuti is a valuable species in the aquarium trade, but export of wild-caught individuals from Brazil (as opposed to captive bred) is illegal.

Freshwater stingrays are often kept in aquariums, but require a very large tank and will eat small tank mates. [18] [26] Although generally non-aggressive, their venomous stinger represents a risk and on occasion aquarists have been stung. [32] The ease of keeping varies significantly: Some such as Potamotrygon motoro are considered relatively hardy in a captive setting, [33] while others such as Paratrygon aiereba, Plesiotrygon nana and Potamotrygon tigrina are much more difficult to maintain. [26]

Several species are commonly bred in captivity, especially at East and Southeast Asian fish farms, which produce thousands of offspring each year. [18] The more serious captive breeding efforts only began in the late 1990s when Brazil put in restrictions on their export of wild-caught individuals. [18] Some captive farms produce hybrids (both intentionally to get offspring with new patterns and unintentionally because of a lack of males), but this practice is generally discouraged. [18] [26] In several US states there are regulations in place that limit the keeping of freshwater stingrays. [26]

Conservation

Potamotrygon tigrina is an endangered species that only was scientifically described in 2011 Potamotrygon tigrina (Tennessee Aquarium, Chattanooga).jpg
Potamotrygon tigrina is an endangered species that only was scientifically described in 2011

The status of most species is relatively poorly known, but overall it is suspected that river stingrays are declining due to capture (for food and the aquarium industry) and habitat loss (mainly due to dams and pollution from mining). [29]

Zoos and public aquariums in Europe and North America have initiated programs, including studbooks, for several Potamotrygonidae species. [26] [35]

Dams

Some freshwater rays are threatened by dams, but Potamotrygon falkneri was able to spread to the upper Parana basin due to the Itaipu Dam Potamotrygon castexi.jpg
Some freshwater rays are threatened by dams, but Potamotrygon falkneri was able to spread to the upper Paraná basin due to the Itaipu Dam

Dams represent a risk to some species, but others may benefit from them. For example, the Guaíra Falls disappeared after the completion of the Itaipu Dam, allowing Potamotrygon amandae (formerly misidentified as P. motoro) and P. falkneri to spread into the upper Paraná basin. [36] [37] When the Tucuruí Dam was completed, there was an increase in potential prey animals, allowing the population of P. henlei to increase. [38] In contrast, dams threaten some species such as P. magdalenae by isolating populations and preventing gene flow, [39] and others such as P. brachyura generally avoid lentic habitats, including the reservoirs created by river impoundment. [12]

Fishing and capture

In addition to the large numbers caught for food (hundred of tons per year in the Brazilian Amazon alone), [29] many are killed because of the risk their stings represent to locals and tourists. In the Amazon, it has been estimated that many thousand river stingrays are removed from certain areas to minimize the risk to ecotourism. [7] Such removal is unregulated by the authorities, as not considered fishing in the traditional sense. [7]

Initially Brazil completely banned all exports of wild-caught freshwater stingrays for the aquarium trade, but have since introduced quotas for some species. From 2010 to 2015, between c. 4,600 and 5,700 of six species (the vast majority were P. leopoldi and P. wallacei ; the latter formerly referred to as P. cf. histrix) were legally exported from Brazil per year. [29] The income generated from these are important to several small fishing communities. [7] [40] Other primary exporters of wild-caught freshwater stingrays are Colombia and Peru. [41] A level of illegal exports also occur, [29] and to curb this Paratrygon aiereba (in Colombia) and several Potamotrygon species (in Brazil and Colombia) have been included on CITES Appendix III. [42] It has been suggested that all members of the family should be included on Appendix III, with Paratrygon and a few Potamotrygon species on Appendix II. [41] [43]

Taxonomy and species

The taxonomy of the river stingrays is complex and undescribed species remain. The two species of Styracura were only moved to this family in 2016. [5] Among the freshwater species, Heliotrygon and Paratrygon are sister genera, and Plesiotrygon and Potamotrygon are sister genera. [44]

Subfamily Styracurinae

The two Styracura (here S. schmardae) are the only members of the family from marine waters Himantura schmardae xelha.jpg
The two Styracura (here S. schmardae ) are the only members of the family from marine waters

Subfamily Potamotrygoninae

At up to 1.6 m (5.2 ft) in disc width and 110 kg (240 lb) in weight, Paratrygon aiereba is one of the largest species in the family Paratrygon shedd.jpg
At up to 1.6 m (5.2 ft) in disc width and 110 kg (240 lb) in weight, Paratrygon aiereba is one of the largest species in the family
Plesiotrygon (here P. iwamae with part of tail missing) is very long-tailed compared to other genera in the family Plesiotrygon iwamae (Buffalo Zoo).jpg
Plesiotrygon (here P. iwamae with part of tail missing) is very long-tailed compared to other genera in the family
Potamotrygon motoro is one of the best-known and most widespread species in the family Potamotrygon adventure aquarium.jpg
Potamotrygon motoro is one of the best-known and most widespread species in the family

See also

Related Research Articles

<span class="mw-page-title-main">Myliobatiformes</span> Order of cartilaginous fishes

Myliobatiformes is one of the four orders of batoids, cartilaginous fishes related to sharks. They were formerly included in the order Rajiformes, but more recent phylogenetic studies have shown the myliobatiforms to be a monophyletic group, and its more derived members evolved their highly flattened shapes independently of the skates.

<span class="mw-page-title-main">Long-tailed river stingray</span> Species of cartilaginous fish

The long-tailed river stingray or antenna ray is a species of freshwater stingray in the family Potamotrygonidae. It is found in the Amazon basin in South America, ranging from Ecuador to Belém. It lives in the main channel of the Amazon River and lower parts of its major tributaries.

<span class="mw-page-title-main">Ocellate river stingray</span> Species of cartilaginous fish

The ocellate river stingray, also known as the peacock-eye stingray or black river stingray, is a species of freshwater stingray in the family Potamotrygonidae. It was the first species to be described in the family and is also the most widespread, ranging throughout much of the Río de la Plata, Amazon, Mearim and Orinoco basins in tropical and subtropical South America. It is sometimes kept in aquaria.

<i>Potamotrygon</i> Genus of cartilaginous fishes

Potamotrygon is a genus of freshwater stingrays in the family Potamotrygonidae native to the rivers of South America, and sometimes seen in the aquarium trade. It inhabits rivers of tropical and subtropical climates, especially those of the Amazon basin and is virtually present in all South American countries, except for Chile.

<span class="mw-page-title-main">Chupare stingray</span> Species of cartilaginous fish

The chupare stingray or Caribbean whiptail stingray is a species of stingray in the family Potamotrygonidae, found in the western Atlantic Ocean from the Gulf of Campeche to Brazil, including the Antilles. The presence of this species in the Gulf of Mexico has not been confirmed. It also occurs in the Bahamas. It usually inhabits sandy substrates, sometimes near coral reefs, and is an infrequent visitor to the Amazon River estuary. Leonard Compagno doubted the taxonomic validity of this species in his 1999 Checklist of Living Elasmobranchs.

<span class="mw-page-title-main">Bigtooth river stingray</span> Species of cartilaginous fish

The bigtooth river stingray or Tocantins River ray is a species of freshwater fish in the family Potamotrygonidae. It is endemic to the lower Tocantins basin and Araguaia basin in Brazil, and prefers muddy bottoms. It is sometimes kept in aquaria. This stingray is generally common and its population increased after the Tucuruí Dam was completed, unlike many other species in its range.

<span class="mw-page-title-main">Xingu River ray</span> Species of cartilaginous fish

The River stingray, white-blotched river stingray, or polka-dot stingray is a species of freshwater fish in the family Potamotrygonidae. It is endemic to the Xingu River basin in Brazil and as such prefers clear waters with rocky bottoms. It is sometimes kept in aquaria, like its more common relative the Motoro.

The raspy river stingray, mosaic stingray or arraia is a species of freshwater fish in the family Potamotrygonidae. This stingray is endemic to the Amazon basin in Brazil, where known from the Amazon–Pará River, the Madeira River basin, Uatumã River and lower Tocantins River.

<span class="mw-page-title-main">Pacific chupare</span> Species of cartilaginous fish

The Pacific chupare or Pacific whiptail stingray is a species of stingray in the family Potamotrygonidae. It has been reported off the Pacific coast of Central America from Oaxaca, Mexico to Costa Rica, and also around the Galapagos Islands. It is usually found in shallow water on soft silty or muddy flats; it is unknown whether this species is tolerant of low salinity like the related chupare stingray. Leonard Compagno doubted the taxonomic validity of this species in his 1999 Checklist of Living Elasmobranchs.

<span class="mw-page-title-main">Porcupine river stingray</span> Species of cartilaginous fish

The porcupine river stingray is a species of river stingray in the family Potamotrygonidae, the type of the Potamotrygon genus. It is found in the basins of the Paraná and Paraguay River basins in South America. Most chemical weathering of minerals seems to take place in the upland drainage basins rather than on the floodplains, and most major solutes display conservative mixing in the river-floodplain system. The population in the Rio Negro basin was described as a separated species, P. wallacei, in 2016.

<span class="mw-page-title-main">Short-tailed river stingray</span> Species of cartilaginous fish

The short-tailed river stingray is a species of river stingray native to the Río de la Plata Basin in South America. It is sometimes known as the giant freshwater stingray, but this name is typically used for the southeast Asian Urogymnus polylepis.

Heliotrygon is a genus of freshwater stingrays in the family Potamotrygonidae. The genus is endemic to the Amazon basin in South America. Despite being discovered decades earlier, the genus was only scientifically described in 2011. They mainly live in deep river channels, but approach the shore at night to feed on fish.

Heliotrygon rosai, or Rosa's round ray, is a species of freshwater fish in the family Potamotrygonidae. It is native to the Amazon basin in South America. Its maximum disc width is 80 cm (2.6 ft) and the stinger is greatly reduced, rendering it virtually harmless. It has not been evaluated by the IUCN red list.

Heliotrygon gomesi, or Gomes's round ray, is a species of freshwater stingray native to the western Amazon basin in South America, specifically Brazil. It is the type species of its genus. It spends the day in deep river channels, but moves closer to the shore at night to feed.

<i>Paratrygon</i> Genus of cartilaginous fishes

Paratrygon is a genus of cartilaginous fish in the family Potamotrygonidae.

<i>Paratrygon aiereba</i> Species of cartilaginous fish

Paratrygon aiereba also known as discus ray, manzana ray or ceja ray is a river stingray from the Amazon basin in South America.

<i>Potamotrygon falkneri</i> Species of cartilaginous fish

Potamotrygon falkneri, the largespot river stingray or reticulated freshwater stingray, is a species of freshwater stingray in the family Potamotrygonidae from tropical and subtropical South America. It is sometimes seen in the aquarium trade, but requires a very large tank.

<i>Potamotrygon tigrina</i> Species of cartilaginous fish

Potamotrygon tigrina, also known as the tiger river stingray, is a species of freshwater ray in the family Potamotrygonidae. This endangered species is endemic to black- and whitewater rivers in the upper Amazon basin in northeastern Peru. It is sometimes kept in aquariums and has been bred in captivity, but it is generally a sensitive species.

<i>Styracura</i> Genus of cartilaginous fishes

Styracura is a genus of stingray in the family Potamotrygonidae and the only genus in the subfamily Styracurinae. The two species in this genus were formerly included in Himantura, but were moved to Styracura in 2016 based on morphology and molecular evidence. Unlike other members of the family Potamotrygonidae, also known as freshwater stingrays, Styracura are found in the tropical West Atlantic and East Pacific.

<i>Potamotrygon rex</i> Species of freshwater stingray

Potamotrygon rex, the great river stingray, is a species of freshwater stingray belonging to the family Potamotrygonidae, native to South America in the Neotropical region. P. rex, along with some other Potamotrygon species form a sub-species group known as "black stingrays" known by their similar features and their locality to rivers draining the Central Brazilian Shield. Specifically, it is native to the Rio Tocantins in the central Brazilian state of Tocantins. It is quite a large organism, weighing up to 20 kg. Its appearance is dark brown to blackish with distinct clusters of yellow-orange spots around similarly colored ocelli on its dorsal side. Distinguishing features include broad pelvic-fin apices, lack of labial grooves, irregular double row of dorsal tail thorns, and having two angular cartilages associated with each hyomandibula.

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Rosa, R.S.; Charvet-Almeida, P.; Quijada, C.C.D. (2010). "Biology of the South American Potamotrygonid Stingrays". In Carrier, J.C.; Musick, J.A.; Heithaus, M.R. (eds.). Sharks and Their Relatives II: Biodiversity, Adaptive Physiology, and Conservation. Marine Biology. Vol. 20100521. CRC Press. pp. 241–285. doi:10.1201/9781420080483-c5 (inactive 2024-11-11). ISBN   978-1-4200-8047-6.{{cite book}}: CS1 maint: DOI inactive as of November 2024 (link)
  2. 1 2 Duncan, W.P.; M.N. Fernandes (2010). "Physicochemical characterization of the white, black, and clearwater rivers of the Amazon Basin and its implications on the distribution of freshwater stingrays (Chondrichthyes, Potamotrygonidae)". PanamJAS. 5 (3): 454–464.
  3. 1 2 3 4 5 6 7 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. doi: 10.11646/zootaxa.4167.1.1 . PMID   27701358.
  4. 1 2 3 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. PMID   27470808.
  5. 1 2 3 4 5 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. PMID   27811760.
  6. 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.
  7. 1 2 3 4 Góes de Araújo, M.L.; P. Charvet-Almeida; M.P. Almeida; H. Pereira (2004). "Freshwater Stingrays (Potamotrygonidae): status, conservation and management challenges". Information Document. AC 20 (8): 1–6.
  8. 1 2 3 4 5 6 Last; White; de Carvalho; Séret; Stehmann; Naylor, eds. (2016). Rays of the World. CSIRO. ISBN   978-0-643-10914-8.
  9. 1 2 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. doi:10.11646/zootaxa.4107.4.5. PMID   27394840.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  10. No recognised taxon options: order, family, genus, species, subspecies.
  11. Oddone M.C., Velasco G., Rincon G. (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.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. 1 2 Lucifora; Barbini; Vegh; Scarabotti; Vargas; Solari; Mabragaña; Díaz de Astarloa (2016). "Geographic distribution of the short-tailed river stingray (Potamotrygon brachyura): assessing habitat loss and fishing as threats to the world's largest obligate freshwater elasmobranch". Marine and Freshwater Research. 67 (10): 1463–1478. doi:10.1071/MF15003. hdl: 11336/38346 . S2CID   52245299.
  13. 1 2 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. doi:10.11646/zootaxa.4150.5.2. PMID   27615813.
  14. Shibuya, A.; M.L.G. Araújo; J.A.S. Zuanon (2009). "Analysis of stomach contents of freshwater stingrays (Elasmobranchii, Potamotrygonidae) from the middle Negro River, Amazonas, Brazil". Pan-American Journal of Aquatic Sciences. 4 (4): 466–475.
  15. Kolmann, M.A.; K.C. Welch Jr.; A.P. Summers; N.R. Lovejoy (2016). "Always chew your food: freshwater stingrays use mastication to process tough insect prey". Proceedings of the Royal Society B. 283 (1838): 20161392. doi:10.1098/rspb.2016.1392. PMC   5031661 . PMID   27629029.
  16. 1 2 Charvet-Almeida, P.; M.L. Góes de Araújo; M. Pinto de Almeida (2005). "Reproductive Aspects of Freshwater Stingrays (Chondrichthyes: Patamotrygonidae) in the Brazilian Amazon Basin". Journal of Northwest Atlantic Fishery Science. 35: 165–171. doi: 10.2960/j.v35.m502 .
  17. Pedreros-Sierra, T.d.M.; D.M. Arrieta-Prieto; P.A. Mejía-Falla (2016). "Reproductive system of females of the Magdalena river endemic stingray Potamotrygon magdalenae: Anatomical and functional aspects". Journal of Morphology. 277 (5): 680–697. doi:10.1002/jmor.20527. PMID   26968745. S2CID   36752114.
  18. 1 2 3 4 5 6 Bleher, H.yn (13 June 2016). "Definitive guide to South American freshwater rays". Practical Fishkeeping. Retrieved 26 October 2017.
  19. Wheeler, Quentin (10 April 2011). "New to Nature No 37: Heliotrygon stingrays". The Guardian. Retrieved 25 October 2017.
  20. Thorson, T.B.; J.K. Langhammer; M.I. Oetinger (1988). "Periodic shedding and replacement of venomous caudal spines, with special reference to South American freshwater stingrays, Potamotrygon spp". Environmental Biology of Fishes. 23 (4): 299–314. doi:10.1007/bf00005241. S2CID   21482482.
  21. Froese, Rainer; Pauly, Daniel (eds.). "Family Potamotrygonidae". FishBase . January 2017 version.
  22. Froese, Rainer; Pauly, Daniel (eds.). "Potamotrygon schuhmacheri". FishBase . January 2017 version.
  23. Dawes, J. (2001). Complete Encyclopedia of the Freshwater Aquarium. New York: Firefly Books Ltd. ISBN   1-55297-544-4.
  24. 1 2 Grenard, S. "Stingray injuries, envenomation, and medical management". potamotrygon.de. Retrieved 22 October 2017.
  25. 1 2 3 4 5 da Silva, N.J. Jr.; K.R.C. Ferreira; R.N.L. Pinto; S.D. Aird (2015). "A Severe Accident Caused by an Ocellate River Stingray (Potamotrygon motoro) in Central Brazil: How Well Do We Really Understand Stingray Venom Chemistry, Envenomation, and Therapeutics?". Toxins. 7 (6): 2272–2288. doi: 10.3390/toxins7062272 . PMC   4488702 . PMID   26094699.
  26. 1 2 3 4 5 6 Reynolds; Hornbrook; Stettner; Terrell (2017). Smith; Warmolts; Thoney; Hueter; Murray; Ezcurra (eds.). Husbandry of freshwater stingrays. Elasmobranch Husbandry. Vol. Manual II. Special Publication of the Ohio Biological Survey. pp. 99–112. ISBN   978-0-86727-166-9.
  27. "Freshwater stingray venom varies according to sex and age". AGÊNCIA FAPESP. Retrieved 2020-10-20.
  28. Juliana Luiza Varjão Lameiras (24 May 2013). PERFIS PROTEICOS, ENZIMÁTICOS E MIOTOXICIDADE INDUZIDOS PELOS VENENOS DAS ARRAIAS AMAZÔNICAS Plesiotrygon iwamae Rosa, Castello & Thorson, 1987 E Potamotrygon motoro Müller & Henle, 1841 (Chondrichthyes – Potamotrygonidae) [Protein, Enzyme and Mycotoxity Profiles Induced by Venom from the Amazonian Stingrays Plesiotrygon iwamae Rosa, Castello & Thorson, 1987 and Potamotrygon motoro Müller & Henle, 1841 (Chondrichthyes – Potamotrygonidae)](PDF) (Thesis) (in Brazilian Portuguese). Manaus-AM: Federal University of Amazonas.
  29. 1 2 3 4 5 6 7 8 9 Ramos, H.A.C. (May 2017), Commercial species of freshwater stingrays in Brazil, Department of Sustainable Use of Biodiversity and Forests, Brazilian Institute of Environment and Renewable Natural Resources and Ministry of the Environment, pp. 1–33
  30. Charvet-Almeida, P., Soto, J.M.R. & Pinto de Almeida, M. (2009). "Potamotrygon brachyura". IUCN Red List of Threatened Species . 2009: e.T161687A5480430. doi: 10.2305/IUCN.UK.2009-2.RLTS.T161687A5480430.en .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  31. Junior, H.J.; J.L.C. Cardoso; D.G. Neto (2013). "Injuries by marine and freshwater stingrays: history, clinical aspects of the envenomations and current status of a neglected problem in Brazil". J. Venom Anim. Toxins Incl. Trop. Dis. 19 (16): 2272–2288. doi: 10.1186/1678-9199-19-16 . PMC   3735412 . PMID   23895313.
  32. Brisset, I.B.; A. Schaper; P. Pommier; L. de Haro (2006). "Envenomation by Amazonian freshwater stingray Potamotrygon motoro: 2 cases reported in Europe". Toxicon. 47 (1): 32–34. doi:10.1016/j.toxicon.2005.09.005. PMID   16303158.
  33. "Potamotrygon motoro". SeriouslyFish. Retrieved 27 October 2017.
  34. 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. doi:10.11646/zootaxa.2827.1.1.
  35. "Elasmobranch TAG News" (PDF). Elasmobranch Taxon Advisory Group. 1 March 2017. Retrieved 27 October 2017.
  36. 1 2 Ferreira Júlio Júnior Horácio, Dei Tós Claudenice, Antonio Agostinho Ângelo, Simone Pavanelli Carla (2009). "A massive invasion of fish species after eliminating a natural barrier in the upper rio Paraná basin". Neotropical Ichthyology. 7 (4): 709–718. doi: 10.1590/S1679-62252009000400021 .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  37. 1 2 3 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)". Neotropical Ichthyology. 11 (4): 693–737. doi: 10.1590/s1679-62252013000400001 .
  38. Rincon, G. (SSG South America Regional Workshop, June 2003) (2004). "Potamotrygon henlei". IUCN Red List of Threatened Species . 2004: e.T39402A10225965. doi: 10.2305/IUCN.UK.2004.RLTS.T39402A10225965.en .{{cite journal}}: CS1 maint: multiple names: authors list (link) CS1 maint: numeric names: authors list (link)
  39. Lasso, C., Mesa-Salazar, L., Sanchez-Duarte, P., Usma, S. & Villa-Navarro, F. (2016). "Potamotrygon magdalenae". IUCN Red List of Threatened Species . 2016: e.T161385A61472512. doi: 10.2305/IUCN.UK.2016-1.RLTS.T161385A61472512.en .{{cite journal}}: CS1 maint: multiple names: authors list (link)
  40. Tuccinardi, M. (21 May 2016). "Rio Negro 'Hystrix' Stingray Gets a Name: Potamotrygon wallacei". Reef to Rainforest Media. Retrieved 26 October 2017.
  41. 1 2 Listing of the species Potamotrygon motoro and Potamotrygon schroederi in Appendix II in accordance with Article II 2a (b) of the Convention, and Resolution Conf. 9.24 (Rev. CoP15), Sixteenth meeting of the Conference of the Parties Bangkok (Thailand), CITES, 3–14 March 2013, pp. 1–22
  42. "Appendices I, II and III". CITES. 4 October 2017. Retrieved 26 October 2017.
  43. "17.246 to 17.249 Freshwater stingrays (Potamotrygonidae spp.)". CITES. Archived from the original on 28 October 2017. Retrieved 26 October 2017.
  44. 1 2 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.
  45. 1 2 3 Fontenelle, J.P.; M.R. de Carvalho (2017). "Systematic Revision of the Potamotrygon scobina Garman, 1913 Species-complex (Chondrichthyes: Myliobatiformes: Potamotrygonidae), with the Description of Three New Freshwater Stingray Species from Brazil and Comments on Their Distribution and Biogeography". Zootaxa. 4310 (1): 1. doi:10.11646/zootaxa.4310.1.1.
  46. 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 .
  47. 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)" (PDF). Zootaxa. 3765 (3): 249–268. doi:10.11646/zootaxa.3765.3.2. PMID   24870898.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  48. 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): 594–612. doi:10.1111/jfb.14050. PMID   31095730.
  49. 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. doi:10.11646/zootaxa.2827.1.1.