Golden Dorado (Salminus brasiliensis)

Salminus brasiliensis, also known as the golden dorado, dorado, river tiger, dourado, or jaw characin is a large, predatory characiform freshwater fish found in central and east-central South America. Despite having Salminus in its name, the dorado is not related to any species of salmon, nor to the saltwater fish also called dorado. It is very popular among recreational anglers and supports large commercial fisheries.

Name
​Dorado, both in the name of the fish and other uses such as the El Dorado legend, originates from the Latin word for gold, auratus (later modified into dauratus in Vulgar Latin, and subsequently oro in Italian and Spanish, and ouro in Portuguese).
The Portuguese word dourado and Spanish dorado both mean 'golden' and is applied to the fish due to its color displaying golden reflections.
DescriptionThe golden dorado has a large head, with powerful jaws filled with sharp teeth. Adults are yellow-golden in color, but juveniles are more silvery.[5] Immatures (to a lesser extent adults) resemble Brycon hilarii and Salminus hilarii.  It reaches maturity around 37 cm (15 in) long. The average size of the golden dorado is about 3–10 kg (6.6–22.0 lb). The largest recorded size is 1.3 m (51 in) in length and 34 kg (75 lb) in weight. Females grow considerably larger than males, but otherwise the sexes are similar. It is the largest scaled freshwater fish in the Río de la Plata Basin (the only fish that can surpass it in size are certain river stingrays  and catfish; both scaleless).

Distribution, habitat and life cycle
A golden dorado in Bonito, Pantanal, Brazil (four superficially similar Brycon hilarii in the background, a species mimicked by juvenile golden dorados)

The golden dorado is native to warm freshwater habitats in southern Brazil, Paraguay, Uruguay, Bolivia and northern Argentina. Here it inhabits the Paraguay (including the Pantanal), Paraná, Uruguay, Chapare, Mamoré and Guaporé River basins, and the drainage of the Lagoa dos Patos. Outside its native range, the golden dorado has been introduced to several southeast Brazilian river basins, notably Doce, Paraíba do Sul, Iguazu and Guaraguaçu.

Other South American river basins hold relatives of this species: S. franciscanus in the São Francisco Basin, S. hilarii in the upper Paraná, Amazon and Orinoco basins, and S. affinis in the Santiago and Magdalena basins in Ecuador and Colombia.

The golden dorado generally prefers water temperatures between 20 and 28 °C (68–82 °F). It is migratory in response to temperature, season and food sources, and moves upstream, typically about 400 km (250 mi), to spawn in the spring and summer.  It is generally a solitary species, but migrates in groups. The females reach maturity when 4–5 years old and can lay up to 2 million eggs, which are released near the water surface. Golden dorados can reach an age of more than 15 years.