Saw Shark Facts (Order Pristiophoriformes)

The saw shark, also spelled sawshark, is a type of shark named for the way its toothy, flattened snout resembles a saw blade. Saw sharks are members of the order Pristiophoriformes. Fast Facts: Saw Shark Scientific Name: PristiophoriformesCommon Names: Saw shark, sawsharkBasic Animal Group: FishSize: 28-54 inchesWeight: 18.7 pounds (common saw shark)Lifespan: 9-15 yearsDiet: CarnivoreHabitat: Deep continental shelf of temperate, subtropical, and tropical oceansPopulation: UnknownConservation Status: Data Deficient to Near Threatened Species There are two genera and at least eight species of saw shark: Pliotrema warreni (sixgill saw shark)Pristiophorus cirratus (longnose sawshark or common saw shark)Pristiophorus delicatus (tropical saw shark)Pristiophorus japonicus (Japanese saw shark)Pristiophorus lanae (Lanas saw shark)Pristiophorus nancyae (African dwarf saw shark)Pristiophorus nudipinnis (shortnose saw shark or southern saw shark)Pristiophorus schroeder (Bahamas saw shark) Description The saw shark resembles other sharks, except it has a long rostrum (snout) that is edged with sharp teeth. It has two dorsal fins, lacks anal fins, and has a pair of long barbels near the midpoint of the snout. The body is usually yellowish brown with spots, camouflaging the fish against the ocean floor. Size depends on species, but females are generally slightly larger than males. Saw sharks range from 28 inches to 54 inches in length and may weigh up to 18.7 pounds. Saw Shark vs. Saw Fish Both saw sharks and saw fish are cartilaginous fish that have blade-like snouts. However, the saw fish is actually a type of ray and not a shark. The saw shark has gill slits on its sides, while the saw fish has slits on its underside. The saw shark has barbels and alternating large and small teeth, while the saw fish has evenly sized teeth and lacks barbels. Both animals use electroreceptors to detect prey via their electric field. A saw fish has even-sized teeth and gills on its underside. Tsuyoshi Kaminaga / EyeEm / Getty Images Habitat and Range Saw sharks live in the deep waters of the continental shelves of temperate, subtropical, and tropical oceans. They are most common off the coasts of the Indian and Pacific Oceans. Most species live at depths between 40 and 100 meters, although the Bahamas saw shark has been found between 640 and 914 meters. Some species migrate up or down the water column in response to seasonal temperature fluctuations. Diet and Behavior Like other sharks, saw sharks are carnivores that eat crustaceans, squid, and small fish. Their barbels and saws contain sensory organs called ampullae of Lorenzini that detect electric fields emitted by prey. The shark cripples prey and defends against threats by sweeping its toothed saw from side to side. Some species are solitary hunters, while others live in schools. Reproduction and Offspring Saw sharks mate seasonally, but females only give birth every two years. After a 12-month gestation period, females give birth to a litter of 3 to 22 pups. Pups are born with their teeth folded against their snout to protect the mother from injury. Adults care for the young for 2 years. At this point, the offspring are sexually mature and able to hunt on their own. The average lifespan of a saw shark is 9 to 15 years. Conservation Status There are no estimates of the population size or trend of any saw shark species. The International Union for Conservation of Nature (IUCN) classifies the status of saw sharks based on the likelihood each species or its prey is at risk for overfishing or bycatch. The sixgill saw shark is classified as near threatened. The common saw shark, southern saw shark, and tropical saw shark are categorized as least concern. There is insufficient data to evaluate the conservation status of the other species. Saw Sharks and Humans Because of the depths at which they live, saw sharks pose no threat to humans. Some species, such as the longnose saw shark, are intentionally fished for food. Others may be caught and discarded as bycatch by gillnets and trawlers. Sources Hudson, R. J., Walker, T. I., and Day, R. W. Reproductive biology of common sawshark (Pristiophorus cirratus) harvested off southern Australia, Appendix 3c. In: Walker, T. I. and Hudson, R. J. (eds), Sawshark and elephant fish assessment and bycatch evaluation in the Southern Shark Fishery. Final Report to Fisheries Research and Development Corporation. July 2005. Primary Industries Research Victoria, Queenscliff, Victoria, Australia.Last, P.R. and J.D. Stevens. Sharks and Rays of Australia (2nd ed.). CSIRO Publishing, Collingwood. 2009.Tricas, Timothy C.; Kevin Deacon; Peter Last; John E. McCosker; Terence I. Walker. in Taylor, Leighton (ed.). The Nature Company Guides: Sharks Rays. Sydney: Time-Life Books. 1997. ISBN 0-7835-4940-7.Walker, T.I. Pristiophorus cirratus. The IUCN Red List of Threatened Species 2016: e.T39327A68640973. doi:10.2305/IUCN.UK.2016-1.RLTS.T39327A68640973.enWang, Y., Tanaka, S.; Nakaya, K. Pristiophorus japonicus. The IUCN Red List of Threatened Species 2009 : e.T161634A5469437. doi:10.2305/IUCN.UK.2009-2.RLTS.T161634A5469437.en