Longnose sawshark

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Longnose sawshark
Sketchbook of fishes - 25. (Longnose) Saw shark - William Buelow Gould, c1832.jpg
Pristiophorus cirratus, from the Sketchbook of fishes by William Buelow Gould, 1832
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Superorder: Selachimorpha
Order: Pristiophoriformes
Family: Pristiophoridae
Genus: Pristiophorus
Species:
P. cirratus
Binomial name
Pristiophorus cirratus
(Latham, 1794)
Pristiophorus cirratus distmap.png
Range of longnose sawshark (in blue)

The longnose sawshark (Pristiophorus cirratus) or common sawshark, is a sawshark of the family Pristiophoridae.

Contents

Description

The longnose sawshark has a slender, slightly flattened body [2] with a very long rostrum 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, 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 1.37 m (4 ft 6 in). [3] The longnose sawshark can be confused with one of many species of sawfish, a family of rays, 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. [2]

Distribution and habitat

The longnose sawshark is found in the eastern Indian Ocean around southern Australia and Tasmania on the continental shelf at depths of 20 - 600m. [4] While it may venture into bays and estuaries on occasion, longnose sawsharks prefer sandy and gravelly areas offshore between 37–146 m (121–479 ft). [5]

Biology and ecology

Longnose sawsharks feed primarily on small crustaceans. [6] 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. [2]

Like all sawsharks, reproduction is ovoviviparous. Longnose sawsharks give birth every other winter to between 6 and 19 pups in a litter. [7] After a 12-month gestation period, pups are born 27–37 cm (11–15 in) in length. [2] 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. [7]

Human interaction

The longnose sawshark is listed as Least Concern by the International Union for Conservation of Nature (IUCN). It used to be listed as Near Threatened, 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. [1]

Related Research Articles

Sawshark Family of fishes

A sawshark or saw shark is a member of a shark order bearing a unique long, saw-like rostrum edged with sharp teeth, which they use to slash and disable their prey. There are eight species within the Pristiophoriformes, including the longnose or common sawshark, shortnose sawshark, Japanese sawshark, Bahamas sawshark, sixgill sawshark, African dwarf sawshark, Lana's sawshark and the tropical sawshark.

Sawfish Family of fishes

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 with some species reaching lengths of about 7–7.6 m (23–25 ft). They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes. They are also endangered.

Bahamas sawshark Species of shark

The Bahamas sawshark, Pristiophorus schroederi, is a sawshark of the family Pristiophoridae, found in the western Central Atlantic Ocean from the Bahamas and Cuba at depths of between 400 and 1,000 m. These sharks are at least 80 cm long.

Rostrum (anatomy) Anatomy term

Rostrum is a term used in anatomy for a number of phylogenetically unrelated structures in different groups of animals.

Shortnose sawshark Species of shark

The shortnose sawshark, or southern sawshark, is a sawshark of the family Pristiophoridae. The body of this shark is slightly compressed, and its rostrum is narrow. The two dorsal fins are almost identical in size. In color, the dorsal side of this sawshark tends to be uniformly slate gray, with few or no markings. The ventral side is pale white or cream. Females reach around 124 cm (49 in) long, and males reach around 110 cm (43 in) long. These sharks can live up to 9 years.

Japanese sawshark Species of shark

The Japanese sawshark is a species of sawshark in the family Pristiophoridae. This shark has a long, narrow rostrum. Its first dorsal fin originates behind the tips of the pectoral fins, and its caudal fin is angled almost straight in line with the body. The Japanese sawshark reaches a maximum length of up to 1.36 m.

Sixgill sawshark Species of shark

The sixgill sawshark, Pliotrema warreni is a sawshark of the family Pristiophoridae. Presence of 6 pairs of gill slits highlights this genus among sharks; outside Hexanchiformes order, Pliotrema is the only shark with more than 5 gill slits. Unlike other sawsharks, the barbs on this shark's rostrum continue onto the sides of the head. Its barbels are also closer to its mouth than in other species. At maximum, females can reach over 136 cm long, and males can reach over 112 cm long.

Sicklefin weasel shark Species of shark

The sicklefin weasel shark is an uncommon species of ground shark in the family Hemigaleidae. It is native to southern India, southern China, and parts of Southeast Asia, living in shallow waters down to a depth of 170 m (560 ft). This lightly built shark is characterized by its very short mouth, broad upper teeth with serrations only on the trailing edge, and strongly sickle-shaped fins with obvious white tips on the two dorsal fins. It is light grey or bronze in colour, often with small white blotches on its sides; it reaches a maximum known length of 1.1 m (3.6 ft).

The narrow sawfish(Anoxypristis cuspidata), also known as the pointed sawfish or knifetooth sawfish, is a species of sawfish in the family Pristidae, part of the Batoidea, a superorder of cartilaginous fish that include the rays and skates. Sawfish display a circumglobal distribution in warm marine and freshwater habitats. Their extant biodiversity is limited to five species belonging to two genera. The sawfishes are characterised by the long, narrow, flattened rostrum or extension on their snout. This is lined with sharp transverse teeth, arranged in a way that resemble the teeth of a saw and are used for killing prey. It is found in the shallow coastal waters and estuaries of the Indo-West Pacific, ranging from the Red Sea and the Persian Gulf to southern Japan, Papua New Guinea and northern Australia. It is the only living member of the genus Anoxypristis, but was previously included in the genus Pristis. Compared to Pristis, Anoxypristis has a narrower rostral saw with numerous teeth on the distal part and no teeth on the basal one-quarter. This endangered species reaches a length of up to 3.5 m (11 ft).

Dwarf sawfish Species of cartilaginous fish

The dwarf sawfish or Queensland sawfish, Pristis clavata, is a sawfish of the family Pristidae, found in tropical Australia. This endangered species is the smallest species in its family.

Smalltooth sawfish Species of cartilaginous fish

The smalltooth sawfish is a species of sawfish in the family Pristidae. It is found in shallow tropical and subtropical waters in coastal and estuarine parts of the Atlantic. Reports from elsewhere are now believed to be misidentifications of other species of sawfish. It is a critically endangered species that has disappeared from much of its historical range.

Longcomb sawfish Species of cartilaginous fish

The longcomb sawfish, narrowsnout sawfish or green sawfish is a species of sawfish in the family Pristidae, found in tropical and subtropical waters of the Indo-West Pacific. It has declined drastically and is now considered a critically endangered species.

Longnose pygmy shark Species of shark

The longnose pygmy shark is a rare species of squaliform shark in the family Dalatiidae and the only member its genus. It is known only from a handful of specimens collected from the cold oceanic waters of the Southern Hemisphere, between the surface and a depth of 502 m (1,647 ft). Reaching 37 cm (15 in) in length, this diminutive shark is characterized by a slender, dark brown body with a very long, bulbous snout. In addition, it has two spineless dorsal fins of nearly equal size, with the origin of the first lying over the pectoral fin bases. The longnose pygmy shark does not appear substantially threatened by fisheries, and has been assessed as Least Concern by the International Union for Conservation of Nature (IUCN).

Australian angelshark Species of shark

The Australian angelshark is a species of angelshark, family Squatinidae, found in the subtropical waters of southern Australia from Western Australia to New South Wales between latitudes 18°S and 41°S, at depths down to 255 m (840 ft). Its length is up to 1.52 m (5 ft). Reproduction is ovoviviparous, with up to 20 pups in a litter.

Eastern Australian sawshark Species of shark

The Eastern Australian sawshark, Pristiophorus peroniensis, is a sawshark of the family Pristiophoridae, found off southeastern mainland Australia at depths of between 100 and 630 m. Its length is up to 1.36 m.

<i>Pristiophorus</i> Genus of sharks

Pristiophorus is a genus of sawsharks found in the Pacific, Atlantic and Indian oceans. Members of this genus differ from the Sixgill Sawshark (Pliotrema warreni) in having five gill slits. Their rostral sawteeth lack prominent transverse ridges on the basal ledges, and the large teeth are not posteriorly serrated.

Tropical sawshark Species of shark

The tropical sawshark, Pristiophorus delicatus, is a recently described species of sawshark, family Pristiophoridae, formerly known in literature as Pristiophorus sp. B. It is endemic to northeastern Australia, found on the upper continental slope off Queensland from south of the Samaurez Reef, at a depth of 246–405 meters (807–1,329 ft). Its specific epithet delicatus is Latin for "delicate", referring to the fine teeth on its saw-like rostrum.

<i>Pristiophorus nancyae</i> Species of shark

Pristiophorus nancyae, the African dwarf sawshark or dwarf sawshark, is a sawshark of the family Pristiophoridae. The species was discovered in 2011 when a specimen was caught off the coast of Mozambique at a depth of 1,600 ft (490 m).

Squalomorphii Supwerorder of cartilaginous fishes

Squalomorphii is a superorder of cartilaginous fishes, generally characterized by lacking traits such as an anal fin, nictitating membrane, or suborbital shelves in the cranium. Also called squalea, or squalean sharks. There are about 163 living species in 11 families. Squalean sharks are divided into four orders: the Hexanchiformes, Squaliformes, Squatiniformes, and Pristiophoriformes.

<i>Atlanticopristis</i> Extinct genus of cartilaginous fishes

Atlanticopristis is an extinct genus of sclerorhynchid that lived during the Middle Cretaceous (Cenomanian) of what is now the Northeast Region of Brazil, between 100.5 and 93.9 million years ago. Fourteen fossil teeth from Atlanticopristis were found in the Alcântara Formation, and referred to the closely related Onchopristis in 2007; a redescription in 2008 by Portuguese paleontologists Manuel Medeiros and Agostinha Pereira assigned it to a new genus containing one species, Atlanticopristis equatorialis.

References

  1. 1 2 Walker, T.I. (2020). "Pristiophorus cirratus". IUCN Red List of Threatened Species . 2020: e.T39327A176975610. doi: 10.2305/IUCN.UK.2020-3.RLTS.T39327A176975610.en . Retrieved 13 November 2021.
  2. 1 2 3 4 Tricas, Timothy C.; Kevin Deacon; Peter Last; John E. McCosker; Terence I. Walker (1997). Taylor, Leighton (ed.). The Nature Company Guides: Sharks & Rays . Sydney: Time-Life Books. pp.  140. ISBN   0-7835-4940-7.
  3. Froese, Rainer; Pauly, Daniel (eds.) (2006). "Pristiophorus cirratus" in FishBase . May 2006 version.
  4. Raoult, V.; Peddemors, V.; Rowling, K.; Williamson, J. E. (2020). "Spatiotemporal distributions of two sympatric sawsharks (Pristiophorus cirratus and P. Nudipinnis) in south-eastern Australian waters". Marine and Freshwater Research. 71 (10): 1342. doi:10.1071/MF19277. S2CID   216286223.
  5. Compagno, Leonardo, Dando, Marc and Fowler, Sarah. Sharks of the World. Princeton University Press. 2005. pg 132.
  6. Raoult, Vincent; Gaston, Troy F.; Williamson, Jane E. (2015). "Not all sawsharks are equal: Species of co-existing sawsharks show plasticity in trophic consumption both within and between species". Canadian Journal of Fisheries and Aquatic Sciences. 72 (11): 1769–1775. doi:10.1139/cjfas-2015-0307. hdl: 1807/69872 .
  7. 1 2 "Marine Species Identification Portal : Longnose sawshark - Pristiophorus cirratus".