Potamotrygon motoro
Chondrichthyes (/kɒnˈdrɪkθi.iːz/; from Ancient Greek χόνδρος (khóndros) 'cartilage', and ἰχθύς (ikhthús) 'fish') is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage.
They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark.
The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish)
and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class).
Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates.
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.
Like other stingrays, the fishes of this genus have venomous barbs at the base of their tails, and their stings are dangerous to humans. It is said that the natives of South America fear the stingray more than they do fear the piranha.
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.
In at least some species juveniles tend to occur in shallower waters than adults. Most species are strictly freshwater, but a few may range into brackish estuarine habitats in salinities up to at least 12.4%.
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.
The ocellate river stingray (Potamotrygon motoro), 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.
Potamotrygon motoro can grow up to 50 cm (1.6 ft) in disc width, 1 m (3.3 ft) in total length and 35 kg (77 lb) in weight. Its disk is roughly circular in shape, and its eyes are raised from the dorsal surface.
The dorsal coloration is typically beige or brown, with numerous yellow-orange spots with dark rings.
Its exact color, and the arrangement and size of the spots can vary significantly, both from individual to individual and depending on location.
Three primary types have been identified in the Amazon basin, but each of these include a number of subtypes (two additional main types now are considered a separate species, P. marquesi).
The two main Amazonian types, informally known as CD1 and CD2, are found throughout much of the Amazon (except most of the Rio Negro basin) and they often occur together.
Those from the Río de la Plata Basin and Mearim River resemble CD1. Individuals from the Rio Negro and Orinoco basins (which are connected by the Casiquiare canal) are similar to each other and informally known as CD3, but differ from P. motoro elsewhere.
Some individuals of CD3 have spots near the rim of the disc that are connected, forming a chain-like pattern. However, the "marbled" type is generally only reported from the Orinoco basin, including the Ventuari River.
Ocellate river stingrays are sometimes kept in captivity, with requirements similar to other members of Potamotrygon. It is one of the most popular species of freshwater stingrays, but requires a very large tank.
Phylum: Chordata
Class: Chondrichthyes
Order: Myliobatiformes
Family: Potamotrygonidae
Genus: Potamotrygon
Species: P. motoro
Binomial name
Potamotrygon motoro
(J. P. Müller & Henle, 1841)
They can be contrasted with the Osteichthyes or bony fishes, which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark.
The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish)
and Holocephali (chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class).
Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates.
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.
Like other stingrays, the fishes of this genus have venomous barbs at the base of their tails, and their stings are dangerous to humans. It is said that the natives of South America fear the stingray more than they do fear the piranha.
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.
In at least some species juveniles tend to occur in shallower waters than adults. Most species are strictly freshwater, but a few may range into brackish estuarine habitats in salinities up to at least 12.4%.
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.
The ocellate river stingray (Potamotrygon motoro), 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.
Potamotrygon motoro can grow up to 50 cm (1.6 ft) in disc width, 1 m (3.3 ft) in total length and 35 kg (77 lb) in weight. Its disk is roughly circular in shape, and its eyes are raised from the dorsal surface.
The dorsal coloration is typically beige or brown, with numerous yellow-orange spots with dark rings.
Its exact color, and the arrangement and size of the spots can vary significantly, both from individual to individual and depending on location.
Three primary types have been identified in the Amazon basin, but each of these include a number of subtypes (two additional main types now are considered a separate species, P. marquesi).
The two main Amazonian types, informally known as CD1 and CD2, are found throughout much of the Amazon (except most of the Rio Negro basin) and they often occur together.
Those from the Río de la Plata Basin and Mearim River resemble CD1. Individuals from the Rio Negro and Orinoco basins (which are connected by the Casiquiare canal) are similar to each other and informally known as CD3, but differ from P. motoro elsewhere.
Some individuals of CD3 have spots near the rim of the disc that are connected, forming a chain-like pattern. However, the "marbled" type is generally only reported from the Orinoco basin, including the Ventuari River.
Ocellate river stingrays are sometimes kept in captivity, with requirements similar to other members of Potamotrygon. It is one of the most popular species of freshwater stingrays, but requires a very large tank.
Phylum: Chordata
Class: Chondrichthyes
Order: Myliobatiformes
Family: Potamotrygonidae
Genus: Potamotrygon
Species: P. motoro
Binomial name
Potamotrygon motoro
(J. P. Müller & Henle, 1841)