The Amazon River in South America is the largest river by discharge volume of water in the world, and the longest or second-longest river system in the world, a title which is disputed with the Nile.
Osteoglossiformes is a relatively primitive order of ray-finned fish that contains two sub-orders, the Osteoglossoidei and the Notopteroidei. All of at least 245 living species inhabit freshwater. They are found in South America, Africa, Australia and southern Asia, having first evolved in Gondwana before that continent broke up. In 2008, several new species of marine osteoglossiforms were described from the Danish Eocene Fur Formation, dramatically increasing the diversity of this group. This implies that the Osteoglossomorpha is not a primary freshwater fish group with the osteoglossiforms having a typical Gondwana distribution.
Osteoglossomorpha is a group of bony fish in the Teleostei.
The silver arowana is a South American freshwater bony fish of the family Osteoglossidae. Silver arowanas are sometimes kept in aquariums, but they are predatory and require a very large tank.
The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about 7,000,000 km2 (2,700,000 sq mi), or about 35.5 percent of the South American continent. It is located in the countries of Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru, Suriname, and Venezuela, as well as the territory of French Guiana.
Arapaima gigas, also known simply as Arapaima or pirarucu, or paiche, is a species of arapaima native to the basin of the Amazon River. Once believed to be the sole species in the genus, it is among the largest freshwater fish. The species is an obligate air breather, so it needs to come to the surface regularly to breathe air.
Scleropages is a genus of fish in the family Osteoglossidae found in Asia and Australia. All of these species are carnivorous and have great jumping ability. These species are highly valued as aquarium fish, particularly by those from Asian cultures. In 2003, a study redescribed several naturally occurring color varieties of S. formosus into four separate species. The majority of researchers dispute these redescriptions, arguing that the published data are insufficient to justify recognizing more than one Southeast Asian species of Scleropages and that divergent haplotypes used to distinguish the color strains into isolated species were found within a single color strain, contradicting the findings. They are considered monotypic, consisting of closely related haplotypes based on color. The ancestor of the Australian arowanas: S. jardinii and S. leichardti, diverged from the ancestor of the Asian arowanas about 140 million years ago, during the Early Cretaceous period. The morphological similarity of all seven species shows that little evolutionary change has taken place recently for these ancient fish. The genus had a much wider distribution during the early Cenozoic, with fossil remains known from the Paleocene of Niger and Belgium, and from the Eocene of China.
Pseudoplatystoma is a genus of several South American catfish species of family Pimelodidae. The species are known by a number of different common names. They typically inhabit major rivers where they prefer the main channels and tend to stay at maximum depth, but some species can also be seen in lakes, flooded forests, and other freshwater habitats. They have robust bodies, and are important food fish. Recently, their population size has been on the drastic decline due to a variety of factors including overfishing and habitat destruction due to the construction of hydroelectric dams.
Chalakudy River or Chalakudy Puzha is the fifth longest river in Kerala, India. The river flows through Thrissur district, Palakkad district and Ernakulam district of Kerala. The total drainage area of the river is 1704 km2. Out of this, 1404 km2 lies in Kerala and the rest in Tamil Nadu. The length of the river is 145.5 km. Though Chalakudy River in strict geological sense is a tributary of the Periyar river, for all practical purposes it is treated as a separate river by Government and other agencies. The river has gained its name since it flows along the banks of the Chalakudy Town, the major settlement along the course of the river. It is perhaps the most unpolluted and pristine river in the state and even in India due to the limited amount of industries and wastage disposal around it. Chalakudy River and its basin area were one of the most affected rivers during the 2018 Kerala floods.
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.
Apistogramma agassizii, commonly known as Agassiz's dwarf cichlid, is a species of cichlid found in the Marañón and Ucayali River in Peru, some tributaries of the Amazon River, as well as downstream to the estuary in the Atlantic. It is named after the Swiss-American zoologist and geologist Louis Agassiz (1807–1873).
Arapaimidae is a family of freshwater ray-finned fish belonging to the family Osteoglossidae. It includes the South American arapaimas of the Amazon and Essequibo basins and the African arowana from the watersheds of the Sahelo-Sudanese region, Senegal, Gambia, and parts of Eastern Africa. This family is sometimes treated as the subfamily Arapaiminae. A commonly used synonym is Heterotidinae, but according to the ICZN, Arapaimidae has priority.
Arapaima leptosoma is a species of freshwater fish endemic to Brazil. It is a member of the arapaimas, a genus of air-breathing fish that contains some of the world's largest freshwater fish. Like other members of the genus Arapaima, this fish can breathe air. It is known only from the confluence of the Solimões and Purus Rivers in Amazonas, Brazil, although due to the lack of obvious geographic barriers, it likely has a larger range.
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.
Corydoras agassizii is a species of catfish found in the Amazon basin. It can be found in the border area of Peru and Brazil. It lives in tropical waters with a water temperature of 22 – 26 °C, a pH of 6.0 – 8.0 and a hardness of 2 – 25 dH.
Arapaima mapae is a species of freshwater fish endemic to Brazil, where it is known only from Lago do Amapá in Amapá State.
Arapaima agassizii is a species of freshwater fish endemic to Brazil. It is a member of the arapaimas, a genus of air-breathing fish that contains some of the world's largest freshwater fish.
