and a variably sized lower lobe (lower lobe relatively large in Anoxypristis; small to absent in Pristis sawfish). The position of the first dorsal fin compared to the pelvic fins varies and is a useful feature for separating some of the species. There are no anal fins. Like other elasmobranches, sawfish lack a swim bladder (instead controlling their buoyancy with a large oil-rich liver), have a skeleton consisting of cartilage, and the males have claspers, a pair of elongated structures used for mating and positioned on the underside at the pelvic fins. The claspers are small and indistinct in young males. Their small intestines contain an internal partition shaped like a corkscrew, called a spiral valve, which increases the surface area available for food absorption. Size Sawfish are large to very large fish, but the maximum size of each species is generally uncertain. The smalltooth sawfish, largetooth sawfish and green sawfish are among the world's largest fish. They can certainly all reach about in total length and there are reports of individuals larger than , but these are often labeled with some uncertainty. Typically reported maximum total lengths of these three are from . Large individuals may weigh as much as , or possibly even more. Old unconfirmed and highly questionable reports of much larger individuals do exist, including one that reputedly had a length of , another that had a weight of , and a third that was long and weighed . The two remaining species, the dwarf sawfish and narrow sawfish, are considerably smaller, but are still large fish with a maximum total length of at least and respectively. In the past it was often reported that the dwarf sawfish only reaches about , but this is now known to be incorrect. Distribution Range Sawfish are found worldwide in tropical and subtropical waters. Historically they ranged in the East Atlantic from Morocco to South Africa, and in the West Atlantic from New York (United States) to Uruguay, including the Caribbean and Gulf of Mexico. There are old reports (last in the late 1950s or shortly after) from the Mediterranean and these have typically been regarded as vagrants, but a review of records strongly suggests that this sea had a breeding population. In the East Pacific they ranged from Mazatlán (Mexico) to northern Peru. Although the Gulf of California occasionally has been included in their range, the only known