Sawfish
Sawfish are primarily found in coastal marine and estuarine brackish waters, but they are euryhaline (can adapt to various salinities) and also found in freshwater. The largetooth sawfish, alternatively called the freshwater sawfish, has the greatest affinity for freshwater. For example, it has been reported as far as up the Amazon River and in Lake Nicaragua, and its young spend the first years of their life in freshwater. In contrast, the smalltooth, green and dwarf sawfish typically avoid pure freshwater, but may occasionally move far up rivers, especially during periods when there is an increased salinity. There are reports of narrow sawfish seen far upriver, but these need confirmation and may involve misidentifications of other species of sawfish.
Sawfish
"Anoxypristis" contains a single living species that historically was included in "Pristis", but the two genera are morphologically and genetically highly distinct. Today "Pristis" contains four living, valid species divided into two species groups. Three species are in the smalltooth group, and there is only a single in the largetooth group. Three poorly defined species were formerly recognized in the largetooth group, but in 2013 it was shown that "P. pristis", "P. microdon" and "P. perotteti" do not differ in morphology or genetics. As a consequence, recent authorities treat "P. microdon" and "P. perotteti" as junior synonyms of "P. pristis".