The Amazon river dolphin, also known as the boto, bufeo or pink river dolphin, is a species of toothed whale endemic to South America and is classified in the family Iniidae. Three subspecies are currently recognized: I. g. geoffrensis, I. g. boliviensis and I. g. humboldtiana. The position of the Araguaian river dolphin within the clade is still unclear. The three subspecies are distributed in the Amazon basin, the upper Madeira River in Bolivia, and the Orinoco basin, respectively.
A piranha or piraña is any of a number of freshwater fish species in the family Serrasalmidae, or the subfamily Serrasalminae within the tetra family, Characidae in order Characiformes. These fish inhabit South American rivers, floodplains, lakes and reservoirs. Although often described as extremely predatory and mainly feeding on fish, their dietary habits vary extensively, and they will also take plant material, leading to their classification as omnivorous.
A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. Most major blackwater rivers are in the Amazon Basin and the Southern United States. The term is used in fluvial studies, geology, geography, ecology, and biology. Not all dark rivers are blackwater in that technical sense. Some rivers in temperate regions, which drain or flow through areas of dark black loam, are simply black due to the color of the soil; these rivers are black mud rivers. There are also black mud estuaries.
Vandellia is a genus of catfishes native to South America. The species in this genus are the most well-known of the parasitic catfishes also known as candiru, known for their alleged habit of entering the human urethra.
Piaractus mesopotamicus, the small-scaled pacu, Paraná River pacu or simply pacu, is a South American ray-finned fish that is native to the Paraguay-Paraná River basin, but it has been introduced by aquaculture activities in a wider area. In its native range it is also known as the pacú chato, pez chato or mbiraí-piraí.
The Sampit River begins in a swampy area of western Georgetown County, South Carolina, USA. It flows in an easterly direction to Winyah Bay at Georgetown. Only small crafts can navigate the upper parts of the river. The lower river merges into the bay and is deepened by tidal flows, and by dredging.
Pacu is a common name used to refer to several species of omnivorous South American freshwater serrasalmid fish related to piranhas. Pacu and piranha do not have similar teeth, the main difference being jaw alignment; piranha have pointed, razor-sharp teeth in a pronounced underbite, whereas pacu have squarer, straighter teeth and a less severe underbite, or a slight overbite. Pacu, unlike piranha, mainly feed on plant material and not flesh or scales. Additionally, the pacu can reach much larger sizes than piranha, at up to 1.08 m in total length and 40 kg (88 lb) in weight.
The Serrasalmidae (serrasalmids) are a family of characiform fishes, recently elevated to family status. It includes more than 90 species. The name means "serrated salmon family", which refers to the serrated keel running along the belly of these fish. Fish classified as Serrasalmidae are also known by these common names: pacu, piranha, and silver dollar. These common names generally designate differing dental characteristics and feeding habits.
The red-bellied piranha, also known as the red piranha, is a type of piranha native to South America, found in the Amazon, Paraguay, Paraná and Essequibo basins, as well as coastal rivers of northeastern Brazil. This fish is locally abundant in its freshwater habitat. They are omnivorous foragers and feed on insects, worms, crustaceans, and fish. They are not a migratory species but do travel to seek out conditions conducive to breeding and spawning during periods of increased rainfall. Red-bellied piranhas often travel in shoals as a predatory defense but rarely exhibit group hunting behavior. Acoustic communication is common and is sometimes exhibited along with aggressive behaviors. They are a popular aquarium fish.
The tambaqui is a large species of freshwater fish in the family Serrasalmidae. It is native to tropical South America, but kept in aquaculture and introduced elsewhere. It is also known by the names black pacu, black-finned pacu, giant pacu, cachama, gamitana, and sometimes as pacu.
Mylossoma is a genus of serrasalmids from tropical and subtropical South America, including the basins of the Amazon, Orinoco, Lake Maracaibo and Paraguay-Paraná. These common fish are found both in main river sections and floodplains. They support important fisheries and based on a review by IBAMA, they are the seventh most caught fish by weight in the Brazilian Amazon. They primarily feed on plant material such as seeds and fruits, and in their ecology they generally resemble the larger tambaqui. Mylossoma reach up to 28.5 cm (11.2 in) in length and 1 kg (2.2 lb) in weight.
Piaractus is a genus of large serrasalmid from South America. The two traditionally recognized species of Piaractus are very similar in appearance and were formerly included in the genus Colossoma, which currently only contains another similar species, the tambaqui. A third Piaractus was described in 2019 as a new species, but it was formerly considered a subpopulation of P. brachypomus.
Red-bellied pacu can refer to the following species of fish of the subfamily Serrasalminae:
Mylossoma duriventre, the silver mylossoma, is a species of freshwater serrasalmid fish endemic to tropical and subtropical South America. It grows to a maximum length of about 25 cm (10 in) and a weight of 1 kg (2.2 lb). It is the subject of a local fishery, being known as 'pacu' in Brazil and 'palometa' in Venezuela.
A whitewater river is classified based on its chemistry, sediments and water colour. Whitewater rivers have high levels of suspended sediments, giving the water a pH that is near-neutral, a high electric conductivity and a pale muddy, café au lait-like colour. Whitewater rivers are of great ecological importance and are important to local fisheries. The major seasonal Amazonian floodplains known as várzea receive their water from them.
The Marajó várzea (NT0138) is an ecoregion of seasonally and tidally flooded várzea forest in the Amazon biome. It covers a region of sedimentary islands and floodplains at the mouth of the Amazon that is flooded twice daily as the ocean tides push the river waters onto the land. The flooded forests provide food for a wide variety of fruit-eating fish, aquatic mammals, birds and other fauna. It has no protected areas and is threatened by cattle and water-buffalo ranching, logging and fruit plantations.
The Gurupa várzea (NT0126) is an ecoregion of seasonally and tidally flooded várzea forest along the Amazon River in the Amazon biome.
The Purus várzea (NT0156) is an ecoregion of seasonally flooded várzea forest in the central Amazon basin. It is part of the Amazon biome. The ecoregion is home to a vegetation adapted to floods of up to 12 metres (39 ft) that may last for eight months. There is a great variety of fish and birds, but relatively fewer mammals. Ground-dwelling mammals must migrate to higher ground during the flood season. Threats include logging, cattle farming, over-fishing and mercury pollution from gold mining.
The Iquitos várzea (NT0128) is an ecoregion of flooded forest along rivers in Brazil, Peru and Bolivia in the west of the Amazon biome. The forest is seasonally flooded up to 7 metres (23 ft) by whitewater rivers carrying nutrient-rich sediment from the Andes. The meandering rivers often shift course, creating a complex landscape of oxbow lakes, marshes, levees and bars, with grasslands, shrubs and forests in different stages of succession. During the extended flood periods fish enter the forest in search of fruit. The várzea is accessible by the navigable rivers that run through it, and has suffered from extensive deforestation to extract timber and create pasture for livestock.
A clearwater river is classified based on its chemistry, sediments and water colour. Clearwater rivers have a low conductivity, relatively low levels of dissolved solids, typically have a neutral to slightly acidic pH and are very clear with a greenish colour. Clearwater rivers often have fast-flowing sections.
