The longnose sawshark (''Pristiophorus cirratus'') or common sawshark, is a

sawshark A sawshark or saw shark is a member of a shark order (Pristiophoriformes ) bearing a unique long, saw-like Rostrum (anatomy), rostrum (snout or bill) edged with sharp teeth, which they use to slash and disable their prey. There are eight species ...

of the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Pristiophoridae.

Description

The longnose sawshark has a slender, slightly flattened body with a very long

rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...

that can make up to 30% of its total body length. It has pale yellow or grayish-brown dorsal coloring, white ventral coloring, and

variegated Variegation is the appearance of differently coloured zones in the leaves and sometimes the stems and fruit of plants. Species with variegated individuals are sometimes found in the understory of tropical rainforests, and this habitat is the s ...

, sometimes faint dark blotches, spots, and bars on its back. The barbels of the longnose sawshark are halfway down the rostrum, but slightly closer to the rostral tip than the nostrils. Its maximum length is . The longnose sawshark can be confused with one of many species of

sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish wi ...

, a

rays Ray may refer to: Fish * Ray (fish), any cartilaginous fish of the superorder Batoidea * Ray (fish fin anatomy), a bony or horny spine on a fin Science and mathematics * Ray (geometry), half of a line proceeding from an initial point * Ray (gra ...

, but is distinguished by the five gills located on the sides of its head, as opposed to sawfish which have gills located on the underside of the head.

Distribution and habitat

The longnose sawshark is found in the eastern

Indian Ocean The Indian Ocean is the third-largest of the world's five oceanic divisions, covering or ~19.8% of the water on Earth's surface. It is bounded by Asia to the north, Africa to the west and Australia to the east. To the south it is bounded by th ...

around southern

Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...

and

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

on the

continental shelf A continental shelf is a portion of a continent that is submerged under an area of relatively shallow water, known as a shelf sea. Much of these shelves were exposed by drops in sea level during glacial periods. The shelf surrounding an island ...

at depths of 20 - 600m. While it may venture into bays and estuaries on occasion, longnose sawsharks prefer sandy and gravelly areas offshore between .

Biology and ecology

Longnose sawsharks feed primarily on small crustaceans. Individuals find prey by running their barbels over the ocean floor. They use the teeth on their snouts to stir up sediment and strike prey. Like all sawsharks, reproduction is

ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...

. Longnose sawsharks give birth every other winter to between 6 and 19 pups in a litter. After a 12-month gestation period, pups are born in length. Their teeth are folded against the snout at birth, which protects the mother from harm. Longnose sawsharks are highly productive in comparison to other shark species, maturing quickly and only living for around 15 years.

Human interaction

The longnose sawshark is listed as Least Concern by the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natu ...

(IUCN). It used to be listed as

Near Threatened A near-threatened species is a species which has been categorized as "Near Threatened" (NT) by the International Union for Conservation of Nature as that may be vulnerable to endangerment in the near future, but it does not currently qualify fo ...

, but data gathered after 2000 ultimately led to the new classification. Longnose sawsharks are highly productive and are protected by laws that keep their catch rate stable. Large tracts of their range are protected from all shark fishing, helping to buffer their population loss. Their meat is fairly popular in Australia and is said to have an excellent taste. Because of its deep habitat and overall behavior, the longnose sawshark is not a threat to humans.

References

External links

* *
''Pristiophorus cirratus''
at shark-references.com
Fishes of Australia : ''Pristiophorus cirratus''
{{Taxonbar, from=Q1805360 longnose sawshark Marine fish of Southern Australia longnose sawshark Taxa named by John Latham (ornithologist)