Sawfish
Sawfishes, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish with some species reaching lengths of about . They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes.
Largetooth sawfish
As suggested by the alternative name common sawfish, it was once plentiful, but has now declined drastically leading to it being considered a critically endangered species by the IUCN. The main threat is overfishing, but it also suffers from habitat loss. Both their fins (used in shark fin soup) and "saw" (as novelty items) are highly valuable, and the meat is used as food. Because of the "saw" they are particularly prone to becoming entangled in fishing nets. Historically sawfish were also persecuted for the oil in their liver.