Belongs within: Chondrichthyes.
What the fish saw
Published 23 May 2026
Morphology-wise, fish have done some really odd things in their time, and cartilaginous fish have done some of the oddest. And among those cartilaginous oddities, we should definitely count the sawfishes of the Pristidae.
The most distinctive feature of sawfishes is the inspiration for their vernacular name, an elongate rostrum lined on each side by teeth. Sawfishes are thought to use this rostrum in capturing prey, incapaciting small fish and invertebrates with sideways slashes, though actual feeding behaviour has been little observed (Wueringer et al. 2009). They may also use the rostrum to grub through muddy substrates, and thrashing the rostrum assists in defence against threats. In contrast to the successive replacement of teeth seen in most other cartilaginous fish, the rostral teeth in sawfish grow continually from the root.
Five to seven species of sawfish are recognised in the modern fauna, all found in tropical shoreline waters. They are large in size, mostly growing to lengths of 2.5 to four metres, though some truly gigantic individuals of the largetooth sawfish Pristis pristis seven metres long have been recorded historically (for comparison, the largest great white sharks reach around six metres). Most sawfish species will also enter estuaries, sometimes travelling long distances upstream, and some species may even breed in fresh water. The narrow sawfish Anoxypristis cuspidata has a less dorsoventrally flattened, more shark-like habitus than the other sawfishes in the genus Pristis (though sawfish are rays, not sharks); it has been presumed to be more of an active swimmer as a result. Sawfishes are ovoviviparous, with eggs retained in the reproductive tract until they can be released as live young.
The rostral saw may seem a pretty bizarre thing to evolve, but what is even more bizarre is that cartilaginous fishes have evolved this structure at least three times. As well as the sawfishes in the Pristidae, there are the sawsharks of the Pristiophoridae, which resemble small sawfishes in overall habitus but are true sharks rather than rays. Despite their similar appearances, sawfishes and sawsharks rarely if ever share habitats, the latter being deeper-water fishes. And during the Cretaceous, sawfishes shared the ocean with the Sclerorhynchidae, another lineage of saw-snouted rays. Though some have thought the sclerorhynchids and pristids to be closely related, differences in their rostral structure (among other features) indicate that the rostrum enlarged independently in both.
Sawfishes are eaten by humans in some regions, and their saws are prepared as curios for the tourist trade, but they are not a major target of exploitation. They are not directly dangerous to humans, though a thrashing sawfish caught in a net may inflict some damage (an historical account of someone being cut in half in 18th Century India has been regarded with scepticism by recent authorities). Nevertheless, most if not all sawfish species are currently endangered, as their inshore habitat brings them into conflict with human activity. And if they go, the spectrum of fish diversity will be just that much greyer.
Systematics of Pristidae
Pristidae [Pristiformes, Pristoidei]
|--Pristiopsis leichhardtiG75
|--Anoxypristis cuspidata (Latham 1794)CL99
|--Peyeria libyca Weiler 1935CDZ93
`--Pristis Linck 1790C94
|--P. clavata Garman 1906CL99
|--P. lathami Galeotti 1837CDZ93
|--P. microdon Latham 1794 [incl. P. leichhardti (Whitley 1945)]CL99
|--P. pectinata Latham 1794 [incl. P. annandalei]CL99
|--P. perotteti Müller & Henle 1841CL99
|--P. pristis (Linnaeus 1758)CL99
|--P. zephyreus Jordan & Starks in Jorda 1895CL99
`--P. zijsron Bleeker 1851CL99
*Type species of generic name indicated
References
[CDZ93] Cappetta, H., C. Duffin & J. Zidek. 1993. Chondrichthyes. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 593–609. Chapman & Hall: London.
[C94] Case, G. R. 1994. Fossil fish remains from the late Paleocene Tuscahoma and early Eocene Bashi Formations of Meridian, Lauderdale County, Mississippi. Part I. Selachians. Palaeontographica Abteilung A: Paläozoologie—Stratigraphie 230: 97–138.
[CL99] Compagno, L. J. V., & P. R. Last. 1999. Order Pristiformes. Pristidae. Sawfishes. In: Carpenter, K. E., & V. H. Niem (eds) The Living Marine Resources of the Western Central Pacific vol. 3. Batoid fishes, chimaeras and bony fishes part 1 (Elopidae to Linophrynidae) pp. 1410–1417. FAO: Rome.
[G75] Grant, E. M. 1975. Guide to Fishes 3rd ed. The Co-ordinator-General’s Department: Brisbane (Australia).
Wueringer, B. E., L. Squire, Jr & S. P. Collin. 2009. The biology of extinct and extant sawfish (Batoidea: Sclerorhynchidae and Pristidae). Reviews in Fish Biology and Fisheries 19: 445–464.