Overview

Brief Summary

Biology

The ocellate river stingray is often found lying still, buried in the sandy sediment at the bottom of a stream, particularly during the warmest part of the day (2) (5). Like all stingrays, the females of this species produce eggs, but these develop inside the female. The young hatch inside the female and are then 'born' live after a gestation period of no more than three months (5) (6). The litter size of the ocellate river stingray varies massively, from 3 to 21 young (2). Sexual maturity is reached at around three years of age, when the stingray measures between 30 and 35 centimetres across (2). Initially after birth, the ocellate river stingray feeds on plankton, but as it grows, the diet expands to also include small molluscs, crustaceans and the larvae of aquatic insects, while larger adults also eat certain catfish (those belonging to the family Loricaridae) (2). The ocellate has relatively few predators, except for some larger fish and caiman (3).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Description

Remarkable for its habitat, the ocellate river stingray is one of a small group of rays that evolved in freshwater from a marine ancestor (3). The first part of the scientific name reflects this lifestyle, potamos means 'river' in Greek, while the second part, trygon, means 'three angles' (4), and may refer to its body shape. The body of the ocellate river stingray is an oval disc, with a greyish-brown upper surface patterned with distinct yellow-orange spots, and a white underside (2). While the ocellate river stingray is a beautiful species, it is much feared for the single spine borne at the tip of the robust tail, which is capable of delivering a painful sting (2) (5).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Comprehensive Description

Biology

Found in freshwater rivers. It is an extremely dangerous species. Maximum length reported in Axelrod et al., 1991 (Ref. 6398) is 100 cm TL.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Distribution

Range Description

Rio Paraná, middle and lower reaches; Río Uruguay middle, Río de la Plata, Río Pilcomayo and Río Bermejo. Río Guapore, Río Negro, Río Branco, Río de Janeiro and Río Paraguay.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

South America: Uruguay, Paraná-Paraguay, Orinoco, and Amazon River basins.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Widespread in South America.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© FishWise Professional

Source: FishWise Professional

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Range

The ocellate river stingray has a widespread distribution, extending across Argentina, Brazil, Paraguay, Uruguay and Venezuela, where is occurs in the Paraná-Paraguay, Orinoco, and Amazon River basins (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Physical Description

Size

Maximum size: 1000 mm TL
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© FishWise Professional

Source: FishWise Professional

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Max. size

50.0 cm WD (male/unsexed; (Ref. 36687)); max. published weight: 15.0 kg (Ref. 27548)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Type Information

Paratype for Potamotrygon motoro
Catalog Number: USNM 153588
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes
Preparation: Radiograph
Locality: Brazil: Obidos, Para, Brazil, South America
  • Paratype:
Creative Commons Attribution 3.0 (CC BY 3.0)

© Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Fishes

Source: National Museum of Natural History Collections

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Ecology

Habitat

Habitat and Ecology

Habitat and Ecology
Like all river rays, the ocellate river ray is found in calm waters, especially on the sandy margins of lagoons, brooks and streams. They are most commonly caught when water levels are low (August? September and March?April in Río Paraná, Santa Fe region (Castex and Maciel 1965b)), and observed still and partly buried during the warmest period of the day (09.00?20.00). Fishermen also harpoon these rays during floods when they are found resting over vegetation in shallow water. Potamotrygon motoro catches coincide with a rise in water temperature (Castex and Maciel 1965a), with abundance increasing in the Paraná Medio from September to mid January, stabilising in early March, declining in April then disappearing (Martinez Achenbach and Martinez Achenbach 1976). It is possible that they remain permanently in the area, but are concealed on the bottom at other times. Martinez Achenbach and Martinez Achenbach (1976) consider that Potamotrygon species are ovoviviparous. Potamotrygon motoro reaches sexual maturity during its third year, at a disk width of 30?35cm. A specimen with a disk of 30 cm expelled nine foetuses immediately after being captured. Another, with a disk of 45 cm, gave birth to a litter of 15 young, eight females and seven males. The largest foetus was 13.5 cm in diameter and the smallest 9.5 cm. The diameter of the females was between 11? 13.5 cm, whereas the diameter of the males ranged between 9.5?12cm. Female P. motoro were in an advanced stage of pregnancy in January (Castex 1963). Smaller females give birth to fewer young. The litter size is always odd, varying from 3?21 (Martinez Achenbach and Martinez Achenbach 1976).

According to Martinez Achenbach and Martinez Achenbach, plankton is the first food taken after birth. Juveniles complement their diet with small molluscs (Lamellibranchs and Gastropods), crustaceans and the larvae of aquatic insects. Fish of the family Loricaridae, Astyanax sp. and Pimelodella gracilis were found in the stomach contents of adults.

Systems
  • Freshwater
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Environment

benthopelagic; potamodromous (Ref. 51243); freshwater; pH range: 5.0 - 6.0; dH range: 10
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

While most rays are marine, the ocellate river stingray is one of the few species that is restricted entirely to freshwater (1) (5). Like the other river rays, this species favours calm waters, especially the sandy edges of lagoons, brooks and streams (2).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Migration

Potamodromous. Migrating within streams, migratory in rivers, e.g. Saliminus, Moxostoma, Labeo. Migrations should be cyclical and predictable and cover more than 100 km.
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Diseases and Parasites

Procamallanus Infection 17. Parasitic infestations (protozoa, worms, etc.)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Procamallanus Infection 10. Parasitic infestations (protozoa, worms, etc.)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Brevimulticaecum Infestation. Parasitic infestations (protozoa, worms, etc.)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Life History and Behavior

Life Cycle

16 pups were born by one female in captivity (Ref. 57489).
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Molecular Biology and Genetics

Molecular Biology

Barcode data: Potamotrygon motoro

The following is a representative barcode sequence, the centroid of all available sequences for this species.


No available public DNA sequences.

Download FASTA File
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Statistics of barcoding coverage: Potamotrygon motoro

Barcode of Life Data Systems (BOLDS) Stats
Public Records: 14
Specimens with Barcodes: 25
Species With Barcodes: 1
Creative Commons Attribution 3.0 (CC BY 3.0)

© Barcode of Life Data Systems

Source: Barcode of Life Data Systems (BOLD)

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

Conservation Status

IUCN Red List Assessment


Red List Category
DD
Data Deficient

Red List Criteria

Version
3.1

Year Assessed
2005

Assessor/s
Drioli, M. & Chiaramonte, G.

Reviewer/s
Musick, J.A. & Fowler, S.L. (Shark Red List Authority)

Contributor/s

Justification
This assessment is based on the information published in the 2005 shark status survey (Fowler et al. 2005).

The Ocellate River Stingray (Potamotrygon motoro) is a freshwater ray and one of the seven nominal species of this genus inhabiting southern South America. Although this is the most abundant and widespread endemic ray species of the Parano-plata Basin, it is poorly known and its status is uncertain due to the sparse life history and population data available for this species. Further study and a new assessment in the near future is highly recommended, due to this species? limited geographic range and the major impacts to its freshwater habitat.

History
  • 2000
    Data Deficient
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Status

Classified as Data Deficient (DD) on the IUCN Red List (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Population

Population
This is the most abundant and widespread endemic ray species of the Parano-plata.

Population Trend
Unknown
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Threats

Major Threats
All species of river stingray in the Parano-plata Basin have delicious meat and are harpooned by fishermen when seen in shallow water. Artisanal and commercial fishermen also catch some specimens on lines. The attractively patterned juveniles of this species are collected for the ornamental fish trade. The major threats to the species possibly derive from habitat degradation caused by the damming of the Río Paraná system for navigation and hydroelectric plants and the construction of many ports along the river.
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Data deficient (DD)
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Despite being the most abundant and widespread species of Potamotrygon endemic to South America, a lack of information on its life history and the status of populations means that it is not possible to determine the extent to which the ocellate river stingray may be threatened with extinction (1). However, what is known is that a number of factors may be having a detrimental affect on this species. The ocellate river stingray is commonly hunted, with juveniles being taken for the ornamental fish trade and adults being captured for food (1) (2). When water levels in the streams and lagoons is low, or when the rivers flood and the rays can be found resting over vegetation in shallow water, the ocellate river stingray becomes an easy target for fishermen with harpoons. Some artisanal and commercial fishermen also catch this species on lines (2). Furthermore, habitat degradation in some parts of its range may threaten this species, such as the construction of hydroelectric plants and ports along the Río Paraná system (2).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Management

Conservation Actions

Conservation Actions
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© International Union for Conservation of Nature and Natural Resources

Source: IUCN

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Conservation

A legal quota exists for the number of ocellate river stingrays that may be captured and exported, currently standing at 5,000 individuals per year, and it is said that its capture and exportation is monitored (7), although clearly, this does not in any way mitigate the threat of illegal hunting or trade. Further research on this species has been highly recommended, to enable its conservation status to be determined. Given the negative impacts of hunting and habitat degradation that the ocellate river stingray is subject to, it its possible that this freshwater stingray may be threatened (1).
Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Wildscreen

Source: ARKive

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Relevance to Humans and Ecosystems

Benefits

Importance

fisheries: minor commercial; aquarium: public aquariums
Creative Commons Attribution Non Commercial 3.0 (CC BY-NC 3.0)

© FishBase

Source: FishBase

Trusted

Article rating from 0 people

Average rating: 2.5 of 5

Wikipedia

Ocellate river stingray

The ocellate river stingray (Potamotrygon motoro), also known as the peacock-eye stingray, is a potamodromous freshwater ray native to the basins of the Uruguay, Paraná, Orinoco, and Amazon Rivers.

Dark-colored P. motoro swimming at the New England Aquarium.

It is known to grow up to 1 m (3 ft.) TL and 15 kg (33 lb.).[2] Its disk is roughly circular in shape, and its eyes are raised from the dorsal surface. The dorsal coloration is beige or brown, with numerous light orange spots with dark rings. The arrangements of these spots can vary from fish to fish.

Ocellate river stingrays are sometimes kept in captivity, with requirements similar to other members of Potamotrygon.[3] It is one of the most common species of Potamotrygon in the aquarium.

References[edit]

  1. ^ Drioli, M. & Chiaramonte, G. (1994). Potamotrygon motoro. 2006. IUCN Red List of Threatened Species. IUCN 2006. www.iucnredlist.org. Retrieved on 16 October 2006.
  2. ^ Froese, Rainer and Pauly, Daniel, eds. (2007). "Potamotrygon motoro" in FishBase. Mar 2007 version.
  3. ^ Dawes, John (2001). Complete Encyclopedia of the Freshwater Aquarium. New York: Firefly Books Ltd. ISBN 1-55297-544-4. 
Creative Commons Attribution Share Alike 3.0 (CC BY-SA 3.0)

Source: Wikipedia

Unreviewed

Article rating from 0 people

Average rating: 2.5 of 5

Disclaimer

EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!