 Brazil has over 3,000 identified species of freshwater fish and over 500 species of amphibians.As elsewhere in South America, the majority of the freshwater fish species are characiforms (tetras and allies) and siluriforms (catfish), but there are also many species from other groups such as the cyprinodontiforms and cichlids.While the majority of Brazil's fish species are native to the Amazon, the Paraná–Paraguay and the São Francisco river basins, the country also has an unusually high number of troglobitic fish, with 25 species (15% of the total in the world) known so far.