Smalltooth sawfish (Pristis pectinata). Composite X-ray of a section through a smalltooth sawfish, showing its long toothed rostrum or 'saw', which gives sawfish (family Pristidae) their common name. Sawfish use this saw to dig in the sand for crustaceans or to attack prey by vigorously slashing from side to side. Here, where the two X-ray images were spliced, the vertebral column appears to be 'broken' behind the head. This specimen measures 65.5 centimetres in length.