Common sawfish  (Pristis pristis)

Very little is known of this rare sawfish, but features of its biology can be deduced from studies of other sawfish species. All sawfishes are ovoviviparous (2), a method of reproduction whereby the young develop inside a weakly-formed egg shell within the adult female, receiving nourishment from their yolk sac. During development, the sawfish's rostrum is soft and flexible and the teeth are enclosed in a sheath, possibly to protect the female sawfish whilst giving birth. Shortly after birth, the teeth become exposed (5).

Sawfish generally feed on small schooling fish, but are also reported to feed on crustaceans and other bottom-dwelling animals. They attack fish by slashing their ‘saw' sideways through schools, impaling fish on their teeth. The speared fish are scraped off the teeth by rubbing them on the bottom and then ingested whole (5). Sawfish spend much of their time lying on the sea bottom which, as their gills are located on the underside, means that water does not flow over the gills. Like other rays, sawfish overcome this problem by drawing in oxygen-rich water through large holes located behind the eyes, called spiracles, when breathing (8).