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
Old stories often describe sawfish as highly dangerous to humans, sinking ships and cutting people in half, but today these are considered myths and not factual. Sawfish are actually docile and harmless to humans, except when captured where they can inflict serious injuries when defending themselves by thrashing the saw from side-to-side. The saw is also used in self-defense against predators such as sharks that potentially may eat sawfish. In captivity they have been seen using their saws during fights over hierarchy or food.