Order Pristiophoriformes:

Sawsharks 8 species

Cladogram of elasmobranch 
groups, showing the position 
of the sawsharks

Ventral view of the head
of the Common Sawshark
(Pristiophorus cirratus) Lower anterior tooth of
the Common Sawshark 
(Pristiophorus cirratus) Rostral tooth of the
Common Sawshark 
(Pristiophorus cirratus)

A representative pristiophoroid, the Common Sawshark (Pristiophorus cirratus), showing the rostral saw, long nasal barbels, gill slits on the side of the head, and lack of an anal fin that characterizes the group. The inset to the far right is a detail of a rostral tooth, showing the shallow root.

The pristiophoroids look rather like slender sawfishes, but are readily distinguished by a pair of long nasal barbels resembling a Fu Manchu mustache hanging from the underside of the 'saw' about mid-way along its length. The saw itself is an extension of the rostral cartilages supporting the snout. The rostral teeth of sawsharks are replaced when broken or lost, unlike those of sawfishes (in which damaged or missing rostral teeth are not replaced). Sawsharks are strongly bottom-oriented, occurring over sand or mud substrates. They apparently use their electrosensitive ampullae of Lorenzini peppering the undersurface of the saw and their highly sensitive nasal barbels to detect buried prey, which they then debilitate with vigorous side-to-side swipes of the rostral saw. Sawsharks have a small, transverse mouth and tiny, cuspidate teeth. Known prey of these sharks includes small fishes (such as gapers and cornetfishes), crustaceans, and squids.

 

Common Sawshark (Pristiophorus cirratus)

Common Sawshark (Pristiophorus cirratus)

Pristiophoroids grow to a length of about five feet (1.5 metres). Litters of 7 to 17 large pups 11 to 14 inches (28 to 35 centimetres) long are born with the long rostral teeth folded back, possibly preventing injury to the mother; smaller rostral teeth erupt between the larger ones after birth. Temperate sawsharks inhabit shallow bays and estuaries, but one tropical species the Bahamian Sawshark (Pristiophorus schroederi) occurs at depths from 2 100 to 3,000 feet (640 to 915 metres). Sawsharks are fished commercially off southern Australia where two species are caught, the Common Sawshark (Pristiophorus cirratus) and the Southern Sawshark (Pristiophorus nudipinnis) and in the western North Pacific where the Japanese Sawshark (Pristiophorus japonicus) is highly valued for making "kamaboko" (a traditional Japanese fishcake). 

The pristiophoroids include one of the few sharks outside the hexanchoids with more than five pairs of gill slits: the Sixgill Sawshark (Pliotrema warreni), from the southeastern coast of South Africa. All other sawsharks have five pairs of gill slits and are placed in the genus Pristiophorus.

 

ReefQuest Centre for Shark Research
Text and illustrations R. Aidan Martin
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