There are five species of sawfish found in many ecosystems across the world, including coastal waters, estuaries and even fresh water in tropical regions. As predators, these elasmobranchs are important members in regulating the food chain by feeding on fish and crustaceans.
Despite their importance, all five species—the largetooth sawfish, the smalltooth sawfish, the green sawfish, the dwarf sawfish and the narrow sawfish—are listed as endangered under the Endangered Species Act. The International Union of Conservation of Nature (IUCN) lists two of these species, the narrow and dwarf sawfish, as endangered and the other three—smalltooth, green and largetooth sawfish—as critically endangered. Populations are consistently on the decline due to habitat destruction, fishing and detrimental practices such as finning. However, there are signs that populations of the smalltooth sawfish—which were once restricted to a very small range—are slowly recovering.
Here at the National Aquarium, we have two largetooth sawfish in Shark Alley! Unlike other sawfish species, the largetooth sawfish can survive in both fresh water and salt water. Pregnant females give birth near the mouths of the rivers. Largetooth sawfish pups spend their early years—anywhere between four and six years—in river systems or fresh water and then make their way to estuaries and eventually into marine waters as adults.
As regulators of the food chain in both freshwater and saltwater habitats, the diet of a largetooth can vary. Young largetooth sawfish in fresh water often feed on crustaceans, such as prawn, and small fishes, including catfish. As they age and move towards salt water, they begin to feed mainly on fish.
Learn more about how you can help sawfish!