South America has four distinct major river basins represented at Aquaspace.
The Amazon Basin
Lots of megafauna in this large tank. Amazon-specific fish include some of the following key species:
Neon Tetra (Paracheirodon innesi)
Tambaqui / Black Pacu (Colossoma macropomum)
Brachyplatystoma catfish.
Piraiba / Salton Catfish (Brachyplatystoma filamentosum): A giant catfish often considered specific to the vast Amazon river systems.
Arapaima (Arapaima gigas): While some species exist in both the amazon and Orinoco river basins, the specific massive Arapaima gigas is closely tied to Amazonian lakes and swamps.
Pancake Stingrays (Potamotrygonidae): Specific species are restricted to the Amazon.
Megalodoras uranoscopus The giant talking catfish or giant raphael catfish is a species of thorny catfish that is native to the Amazon Basin in Bolivia, Brazil, Colombia, Ecuador and Peru. This species grows to a length of 60 centimetres SL and a maximum weight of 4.6 kilograms. These fish are harvested in local commercial fisheries
The Rio de la Plata Basin
Golden Dorado (Salminus brasiliensis): This large,, popular predatory fish is native to the Paraná, Paraguay, and Uruguay River basins, as well as the Laguna dos Patos. It is distinct from the Amazonian Salminus species and does not inhabit the main Amazon/Orinoco basins.
Sábalo / Streaked Prochilod (Prochilodus lineatus): This detritivore is a dominant species in the Paraná basin, often making up over 50% of the fish biomass. It is essential to the river ecosystem and, while closely related to Amazonian Prochilodus, is distinct in its distribution.
Plata / Yellow Mandi (Pimelodus maculatus): A highly common catfish in the Rio de la Plata system, often used in local fisheries and generally absent from the Amazon/Orinoco.
Paraguay Twig Catfish (Farlowella paraguayensis): A species of armored catfish frequently found in the Paraguay-Paraná river system.
Reticulated Freshwater Stingray (Potamotrygon falkneri): A key stingray species found in the Paraná-Paraguay region.
Cichlids & Tetras
Gymnogeophagus spp. (e.g., G. meridionalis, G. che, G. taroba): This genus of earth-eating cichlids is highly prevalent in the Rio de la Plata and Uruguay River basins, with many species endemic to this region’s temperate waters, setting them apart from tropical Amazonian cichlids.
Australoheros spp. (e.g., A. ykeregua): A genus of cichlids frequently endemic to the Paraná and upper Uruguay River basins.
Buenos Aires Tetra (Hyphessobrycon anisitsi): A popular, hardy tetra native to the La Plata basin, well-adapted to cooler temperatures compared to many Amazonian counterparts.
The Orinoco Basin
Atabapo Altum Angel (Pterophyllum altum): A highly prized aquarium fish specialized to the Orinoco River and its tributaries like the Atabapo.
Orinoco Peacock Bass (Cichla orinocensis): While some peacock bass are in the Amazon, C. orinocensis and C. temensis are specifically iconic to the Orinoco basin.
Atabapo Butterfly Pleco (Dekeyseria pulchra): Specialized pleco restricted to the Orinoco and its rocky, tannin-stained tributaries.
Flag Cichlids (Mesonauta insignis): While other Mesonauta are found in the Amazon, M. insignis is known to inhabit the Orinoco.
Black Arowana (Osteoglossum ferreirai) found in the Orinoco since the 1970’s, possibly introduced.
The Sao Francisco Basin
Key Endemic and Important Species
Conorhynchos conirostris (Pirá): A unique, monotypic catfish with a blue-skinned, proboscis-like mouth.
Lophiosilurus alexandri (Pacamã): A large, flattened catfish endemic to the basin.
Franciscodoras marmoratus: A marbled, armored catfish.
Salminus franciscanus: Known as the São Francisco dourado, a significant game fish.
Pygocentrus piraya: The largest species of piranha.
Orthospinus franciscensis: A characin and the only member of its genus.
Hasemania nana: A small, popular aquarium tetra.
Prochilodus argenteus (Curimatã-pacu): A key, large-sized migrating fish.
Oxydoras niger, the ripsaw catfish or cuiu cuiu, is a species of thorny catfish native to the Amazon, Essequibo and São Francisco basins in Bolivia, Brazil, Colombia, Ecuador, Guyana, Peru and Venezuela. It is the largest member of the Dorididae family.
Key Ecological Groups
Annual Killifish: Over 40 species of annual killifish exist in the basin, particularly from the Cynolebias and Hypsolebias genera.
Catfish (Siluriformes): The basin is rich in armored catfish (Loricariidae), such as Otocinclus xakriaba.