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The '''sawshark''' or '''saw shark''' is an order ('''Pristiophoriformes''') of [[shark]]s bearing a long, saw-like snout edged with sharp teeth, which they use to slash and disable their prey. There are 6 species within the prisiophoriformes family including
The '''sawshark''' or '''saw shark''' is an order ('''Pristiophoriformes''') of [[shark]]s bearing a unique long, saw-like [[rostrum]] (snout or bill) edged with sharp teeth, which they use to slash and disable their prey. There are 6 species within the prisiophoriformes family including Longnose Sawshark-Pristiophorus cirratus, Japanese Sawshark-Pristiophorus japonicus, Southern Sawshark-Pristiophorus nudipinnis, Bahamas Sawshark-Pristiophorus schroederi, Sixgill Sawshark-Pliotrema warreni, and the Tropical Sawshark-Pristiophorus delicatus <ref[http://www.nhptv.org/wild/pristiophoridae.asp]</ref>.
Longnose Sawshark-Pristiophorus cirratus, Japanese Sawshark-Pristiophorus japonicus, Southern Sawshark-Pristiophorus nudipinnis, Bahamas Sawshark-Pristiophorus schroederi, Sixgill Sawshark-Pliotrema warreni, and the Tropical Sawshark-Pristiophorus delicatus <ref[http://www.nhptv.org/wild/pristiophoridae.asp].


The sawshark is found in many areas around the world, but most commonly are found in waters from [[South Africa]] to [[Australia]] and [[Japan]], at depths around 40-100m, but they are often found at much lower depths in tropical regions.Bahamas sawshark was discovered in the deeper waters (640 m to 915 m) of the northwestern [[Caribbean]].
The sawshark is found in many areas around the world, but is most commonly found in waters from the [[Indian Ocean]] to the Southern [[Pacific Ocean]]. They are normally found depths around 40-100m, but can be found at much lower depths in tropical regions. The Bahamas Sawshark was discovered in deeper waters (640 m to 915 m) of the northwestern [[Caribbean]].


==Description and Life Cycle==
==Description and Life Cycle==
Sawsharks have a pair of long [[barbel (anatomy)|barbels]] about halfway along the snout. They have two [[dorsal fin]]s, but lack [[anal fin]]s, and range up to 170cm in length.<ref name=FBS720>[http://www.fishbase.org/Summary/SpeciesSummary.php?id=720 FishBase]</ref> Genus ''Pliotrema'' has six [[gill slit]]s, and ''Pristiophorus'' the more usual five. The teeth of the saw typically alternate between large and small.
Sawsharks have a pair of long [[barbel (anatomy)|barbels]] about halfway along the rostrum. They have two [[dorsal fin]]s, but lack [[anal fin]]s, and range up to 170cm in length.<ref name=FBS720>[http://www.fishbase.org/Summary/SpeciesSummary.php?id=720 FishBase]</ref> Genus ''Pliotrema'' has six [[gill slit]]s, and ''Pristiophorus'' the more usual five. The teeth of the saw typically alternate between large and small.


These sharks typically feed on small fish, [[squid]], and [[crustacean]]s, depending on species. They navigate the ocean floor using the barbels and [[ampullae of Lorenzini]] on the saw to detect [[prey]] in mud or sand, then hit prey with side-to-side swipes of the saw, crippling them. The saw can also be utilized against other predators in defense.
These sharks typically feed on small fish, [[squid]], and [[crustacean]]s, depending on species. They navigate the ocean floor using the barbels and [[ampullae of Lorenzini]] on the saw to detect [[prey]] in mud or sand, then hit prey with side-to-side swipes of the saw, crippling them. The saw can also be utilized against other predators in defense.

Sawsharks have a relatively slow life history. They have liters of 3-22 pups every 1-2 years. After 12 months of gestation, the pups are born at 30cm long. It is interesting to note that while in the mother, pups teeth are inverted into their mouth to avoid harm. Sawsharks typically live more than 15 years <ref [http://eol.org/pages/204500/details].


==Comparison with sawfish==
==Comparison with sawfish==
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|-
|-
| [[Fish gill|Gill]] openings
| [[Fish gill|Gill]] openings
| on the sides
| Peripheral (sides)
| ventral (underside)
| Ventral (underside)
| style="text-align:center"|<ref name=ufl>[http://www.flmnh.ufl.edu/fish/education/questions/sawfishbiology.html Ichthyology: Sawfish Biology] University of Florida, Museum of Natural History. Retrieved 23 March 2013.</ref>
| style="text-align:center"|<ref name=ufl>[http://www.flmnh.ufl.edu/fish/education/questions/sawfishbiology.html Ichthyology: Sawfish Biology] University of Florida, Museum of Natural History. Retrieved 23 March 2013.</ref>
|-
|-
| [[Barbel (anatomy)|Barbels]]
| [[Barbel (anatomy)|Barbels]]
| pair of long barbels about halfway along the saw
| Single pair of barbels on saw
| no barbels
| No barbels
| style="text-align:center"|
| style="text-align:center"|
|-
|-
| Saw teeth
| Saw teeth
| typically alternate between large and small
| Alternate between large and small
| Equal size
| sizes are even
| style="text-align:center"|
| style="text-align:center"|
|-
|-
| Habitat
| Habitat
| deep offshore waters
| Deep offshore waters
| shallow coastal waters
| Shallow coastal waters
| style="text-align:center"|<ref name=ufl />
| style="text-align:center"|<ref name=ufl />
|-
|-
| Size
| Size
| relatively small, reaching only 5&nbsp;ft
| Relatively small, reaching only 5&nbsp;ft
| relatively large, reaching 23&nbsp;ft
| Relatively large, reaching 23&nbsp;ft
| style="text-align:center"|<ref name=ufl />
| style="text-align:center"|<ref name=ufl />
|}
|}

Revision as of 17:00, 7 December 2017

Not to be confused with sawfish.

Sawsharks
Temporal range: Upper Jurassic–recent[1]
Shortnose sawshark, Pristiophorus nudipinnis
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Clade: Neoselachii
Subdivision: Selachimorpha
Superorder: Squalomorphii
Order: Pristiophoriformes
L. S. Berg, 1958
Family: Pristiophoridae
Bleeker, 1859
Genera[2]

The sawshark or saw shark is an order (Pristiophoriformes) of sharks bearing a unique long, saw-like rostrum (snout or bill) edged with sharp teeth, which they use to slash and disable their prey. There are 6 species within the prisiophoriformes family including Longnose Sawshark-Pristiophorus cirratus, Japanese Sawshark-Pristiophorus japonicus, Southern Sawshark-Pristiophorus nudipinnis, Bahamas Sawshark-Pristiophorus schroederi, Sixgill Sawshark-Pliotrema warreni, and the Tropical Sawshark-Pristiophorus delicatus <ref[1]</ref>.

The sawshark is found in many areas around the world, but is most commonly found in waters from the Indian Ocean to the Southern Pacific Ocean. They are normally found depths around 40-100m, but can be found at much lower depths in tropical regions. The Bahamas Sawshark was discovered in deeper waters (640 m to 915 m) of the northwestern Caribbean.

Description and Life Cycle

Sawsharks have a pair of long barbels about halfway along the rostrum. They have two dorsal fins, but lack anal fins, and range up to 170cm in length.[3] Genus Pliotrema has six gill slits, and Pristiophorus the more usual five. The teeth of the saw typically alternate between large and small.

These sharks typically feed on small fish, squid, and crustaceans, depending on species. They navigate the ocean floor using the barbels and ampullae of Lorenzini on the saw to detect prey in mud or sand, then hit prey with side-to-side swipes of the saw, crippling them. The saw can also be utilized against other predators in defense.

Sawsharks have a relatively slow life history. They have liters of 3-22 pups every 1-2 years. After 12 months of gestation, the pups are born at 30cm long. It is interesting to note that while in the mother, pups teeth are inverted into their mouth to avoid harm. Sawsharks typically live more than 15 years Cite error: The <ref> tag has too many names (see the help page). |- | Barbels | Single pair of barbels on saw | No barbels | style="text-align:center"| |- | Saw teeth | Alternate between large and small | Equal size | style="text-align:center"| |- | Habitat | Deep offshore waters | Shallow coastal waters | style="text-align:center"|[4] |- | Size | Relatively small, reaching only 5 ft | Relatively large, reaching 23 ft | style="text-align:center"|[4] |}

Shortnose sawshark
Longnose sawshark

See also

Wikispecies has information related to Pristiophoridae.
Wikimedia Commons has media related to Pristiophoriformes.

References

  1. ^ Froese, Rainer, and Daniel Pauly, eds. (2009). "Pristiophoriformes" in FishBase. January 2009 version.
  2. ^ Froese, Rainer, and Daniel Pauly, eds. (2013). "Pristiophoridae" in FishBase. October 2013 version.
  3. ^ FishBase
  4. ^ a b Cite error: The named reference ufl was invoked but never defined (see the help page).
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