 The smalltooth sawfish has a relatively narrow rostrum ("saw") with 20–32 teeth on each side.For many years, rarity of seeing a sawfish in the wild prevented scientists from collecting conclusive evidence about the use of their distinctive rostrum.This led them to falsely assume that the sawfish, like many other marine vertebrates with a "beak," or an elongated rostrum, follow the rule that the appendage is used to either sense prey or capture prey, but never both.