family of fishes
not to be confused with sawshark
Sawfish, besides known as carpenter sharks, are a family of rays characterized by a long, narrow, flatten dais, or nose extension, lined with crisp cross teeth, arranged in a way that resembles a understand. They are among the largest fish with some species reaching lengths of about 7–7.6 m ( 23–25 foot ). [ 2 ] They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, arsenic well as fresh water rivers and lakes. They are besides endangered. [ 3 ]

They should not be confused with sawsharks ( order Pristiophoriformes ) or the extinct sclerorhynchoids ( order Rajiformes ) which have a similar appearance, or swordfish ( family Xiphiidae ) which have a alike list but a very different appearance. [ 1 ] [ 4 ] Sawfishes are relatively slow breeders and the females give parentage to live young. [ 2 ] They feed on fish and invertebrates that are detected and captured with the function of their visualize. [ 5 ] They are generally harmless to humans, but can inflict unplayful injuries with the meet when captured and defending themselves. [ 6 ] sawfish have been known and hunted for thousands of years, [ 7 ] and play an authoritative fabulous and spiritual function in many societies around the world. [ 8 ] once common, sawfish have experienced a drastic decline in recent decades, and the merely remaining strongholds are in Northern Australia and Florida, United States. [ 4 ] [ 9 ] The five species are rated as Endangered or critically Endangered by the IUCN. [ 10 ] They are hunted for their fins ( shark five soup ), practice of parts as traditional music, their teeth and interpret. They besides face habitat personnel casualty. [ 4 ] Sawfish have been listed by CITES since 2007, restricting international trade in them and their parts. [ 11 ] [ 12 ] They are protected in Australia, the United States and several other countries, meaning that sawfish caught by accident have to be released and violations can be punished with goodly fines. [ 13 ] [ 14 ]

Taxonomy and etymology [edit ]

The scientific names of the sawfish class Pristidae and its type genus Pristis are derived from the Ancient Greek : πρίστης, romanized : prístēs, fall. ‘saw, sawyer ‘. [ 15 ] [ 16 ] Despite their appearance, sawfish are rays ( superorder Batoidea ). The sawfish family has traditionally been considered the sole living member of the order Pristiformes, but recent authorities have broadly subsumed it into Rhinopristiformes, an decree that now includes the sawfish family, arsenic well as families containing guitarfish, wedgefish, banjo rays and the comparable. [ 17 ] [ 18 ] Sawfish quite resemble guitarfish, except that the latter group lacks a watch, and their common ancestor likely was alike to guitarfish. [ 5 ]

Living species [edit ]

The species level taxonomy in the sawfish class has historically caused considerable confusion and was frequently described as chaotic. [ 7 ] only in 2013 was it firm established that there are five living species in two genus. [ 4 ] [ 19 ] Anoxypristis contains a single animation species that historically was included in Pristis, but the two genus are morphologically and genetically highly discrete. [ 1 ] [ 20 ] Today Pristis contains four life, valid species divided into two species groups. Three species are in the smalltooth group, and there is only a single in the largetooth group. [ 4 ] Three ill defined species were once recognized in the largetooth group, but in 2013 it was shown that P. pristis, P. microdon and P. perotteti do not differ in morphology or genetics. [ 19 ] As a consequence, holocene authorities treat P. microdon and P. perotteti as junior synonym of P. pristis. [ 3 ] [ 21 ] [ 22 ] [ 23 ] [ 24 ] [ 25 ]

Extinct ( fossil ) species [edit ]

Pristis lathami.[26] extinct sawfish are frequently only known from their rostral teeth, here from the Eocene species In addition to the living sawfish, there are respective extinct species that only are known from fossil remains. The oldest known is the monotypic genus Peyeria whose remains date back 100 million years, from the Cenomanian age ( Late Cretaceous ), [ 1 ] though it may represent a rhinid quite than a sawfish. [ 27 ] Indisputable sawfish genus emerged in the Cenozoic senesce about 60 million years ago, relatively soon after the Cretaceous–Paleogene batch extinction. Among these are Propristis, a monotypic genus lone known from fossil remains, a well as several extinct Pristis species and several extinct Anoxypristis species ( both of these genera are besides represented by living species ). [ 1 ] [ 28 ] Historically, palaeontologists have not separated Anoxypristis from Pristis. [ 1 ] In contrast, respective extra extinct genus are occasionally listed, including Dalpiazia, Onchopristis, Oxypristis, [ 29 ] and Mesopristis, [ 28 ] but recent authorities broadly include the first two in the kin Sclerorhynchidae and the last two are synonyms of Anoxypristis. [ 1 ] [ 30 ] Fossils of sawfish have been found around the world in all continents. [ 29 ] The extinct class Sclerorhynchidae resemble sawfish. They are known entirely from Cretaceous fossils, [ 1 ] [ 31 ] and normally reached length only of approximately 1 m ( 3.3 foot ). [ 5 ] [ 27 ] Some have suggested that sawfish and sclerorhynchids phase a clade, the Pristiorajea, [ 31 ] while others believe the groups are not particularly close, making the proposed clade polyphyletic. [ 27 ]

appearance and anatomy [edit ]

sawfish are dull brown, grey, green or yellow above, [ 2 ] but the shade varies and iniquity individuals can be about black. [ 32 ] The bottom is pale, [ 32 ] and typically whitish. [ 2 ]

see [edit ]

Upperside of saw of a minute sawfish above and green sawfish below. Notice difference in tooth human body and absence/presence of teeth on radical quarter of snout ( each red or black section on rule is 10 curium or 3.9 in ) The most distinctive feature of sawfish is their saw-like dais with a row of milky teeth ( rostral teeth ) on either side of it. The dais is an extension of the chondrocranium ( “ skull ” ), [ 27 ] made of cartilage and covered in skin. [ 33 ] The snout distance is typically about one-fourth to one-third of the total length of the fish, [ 5 ] but it varies depending on species, and sometimes with age and sexual activity. [ 1 ] The rostral teeth are not teeth in the traditional sense, but heavily modified cuticular denticles. [ 34 ] The rostral teeth grow in size throughout the biography of the sawfish and a tooth is not replaced if it is lost. [ 34 ] [ 35 ] In Pristis sawfish the teeth are found along the stallion distance of the dais, but in adult Anoxypristis there are no tooth on the radical one-fourth of the snout ( about one-sixth in adolescent Anoxypristis ). [ 36 ] [ 37 ] The count of tooth varies depending on the species and can range from 14 to 37 on each side of the dais. [ 2 ] [ 38 ] [ note 1 ] It is common for a sawfish to have slenderly different tooth counts on each side of its dais ( deviation typically does not surpass three ). [ 39 ] [ 40 ] In some species, females on average have fewer teeth than males. [ 1 ] [ 39 ] Each tooth is peg-like in Pristis sawfish, and flattened and broadly trilateral in Anoxypristis. [ 2 ] A combination of features, including fins and dais, are typically used to separate the species, [ 2 ] [ 38 ] but it is possible to do it by the snout entirely. [ 41 ]

Head, body and fins [edit ]

sawfish have a impregnable shark-like body, a flat bottom and a flat head. Pristis sawfish have a rough sandpaper-like clamber texture because of the embrace of cuticular denticles, but in Anoxypristis the skin is largely smooth. [ 2 ] The mouth and nostrils are placed on the bottom of the head. [ 2 ] There are about 88–128 small, blunt-edged tooth in the upper jaw of the mouthpiece and about 84–176 in the lower jaw ( not to be confused with the teeth on the witness ). These are arranged in 10–12 rows on each jaw, [ 42 ] and reasonably resemble a cobble road. [ 43 ] They have modest eyes and behind each is a spiracle, which is used to draw water past the gills. [ 44 ] The gill slits, five on each english, are placed on the bottom of the soundbox near the base of the pectoral fins. [ 43 ] The position of the gill openings separates them from the superficially similar, but by and large much smaller ( up to c. 1.5 megabyte or 5 ft long ) sawsharks, where the slits are placed on the slope of the neck. [ 1 ] [ 45 ] Unlike sawfish, sawsharks besides have a pair of long barbels on the snout ( “ attend ” ). [ 1 ] [ 45 ] sawfish have two relatively high and discrete abaxial fins, wing-like pectoral and pelvic fins, and a dock with a distinct upper berth lobe and a variably sized lower lobe ( lower lobe relatively big in Anoxypristis ; small to absent in Pristis sawfish ). [ 2 ] The position of the first abaxial five compared to the pelvic fins varies and is a utilitarian feature for separating some of the species. [ 2 ] There are no anal fins. [ 42 ] Like other elasmobranches, sawfish lack a float bladder ( alternatively controlling their buoyancy with a large oil-rich liver ), have a skeleton consist of cartilage, [ 46 ] and the males have claspers, a pair of elongated structures used for entangle and positioned on the bottom at the pelvic fins. [ 42 ] The claspers are small and indistinct in young males. [ 38 ] Their small intestines contain an inner division shaped like a corkscrew, called a coil valve, which increases the surface sphere available for food assimilation. [ citation needed ]

size [edit ]

sawfish are bombastic to identical large pisces, but the maximal size of each species is broadly uncertain. The smalltooth sawfish, largetooth sawfish and green sawfish are among the world ‘s largest pisces. They can surely all reach about 6 m ( 20 foot ) in sum duration and there are reports of individuals larger than 7 m ( 23 foot ), but these are much labeled with some doubt. [ 2 ] typically reported utmost total lengths of these three are from 7 to 7.6 megabyte ( 23–25 foot ). [ 2 ] Large individuals may weigh deoxyadenosine monophosphate much as 500–600 kilogram ( 1,102–1,323 pound ), [ 47 ] or possibly even more. [ 48 ] [ 49 ] Old unconfirmed and highly questionable reports of much larger individuals do exist, including one that reputedly had a length of 9.14 meter ( 30 foot ), another that had a weight of 2,400 kg ( 5,300 pound ), and a third that was 9.45 thousand ( 31 foot ) long and weighed 2,591 kilogram ( 5,712 pound ). [ 48 ] The two remaining species, the gnome sawfish and narrow sawfish, are well smaller, but are still large fish with a maximal total length of at least 3.2 meter ( 10.5 foot ) and 3.5 megabyte ( 11.5 foot ) respectively. [ 2 ] [ 50 ] In the past it was often reported that the shadow sawfish only reaches about 1.4 m ( 4.6 foot ), but this is now known to be faulty. [ 51 ]

distribution [edit ]

[3] The smalltooth sawfish is the only species found rigorously in the Atlantic region and the only that survives in the United States .

range [edit ]

sawfish are found worldwide in tropical and subtropical waters. [ 3 ] historically they ranged in the East Atlantic from Morocco to South Africa, [ 52 ] and in the West Atlantic from New York ( United States ) [ 32 ] to Uruguay, including the Caribbean and Gulf of Mexico. [ 3 ] There are old reports ( last in the late 1950s or shortly after ) from the Mediterranean and these have typically been regarded as vagrants, [ 3 ] but a review of records powerfully suggests that this ocean had a breeding population. [ 53 ] In the East Pacific they ranged from Mazatlán ( Mexico ) to northerly Peru. [ 54 ] Although the Gulf of California occasionally has been included in their crop, the merely know Pacific Mexican records of sawfish are from south of its mouth. [ 54 ] They were widespread in the western and cardinal Indo-Pacific, ranging from South Africa to the Red Sea and Persian Gulf, east and north to Korea and southern Japan, through Southeast Asia to Papua New Guinea and Australia. [ 3 ] Today sawfish have disappeared from much of their historical rate. [ 3 ]

habitat [edit ]

sawfish are primarily found in coastal marine and estuarine brackish waters, but they are euryhaline ( can adapt to assorted salinities ) and besides found in fresh water. [ 2 ] The largetooth sawfish, alternatively called the fresh water sawfish, has the greatest affinity for fresh water. [ 55 ] For exemplar, it has been reported arsenic army for the liberation of rwanda as 1,340 kilometer ( 830 secret intelligence service ) up the Amazon River and in Lake Nicaragua, and its unseasoned spend the first years of their life in fresh water. [ 21 ] In contrast, the smalltooth, green and shadow sawfish typically avoid saturated fresh water, but may occasionally move army for the liberation of rwanda up rivers, particularly during periods when there is an increase salt. [ 51 ] [ 56 ] [ 57 ] There are reports of narrow sawfish seen far upriver, but these need confirmation and may involve misidentifications of other species of sawfish. [ 58 ] sawfish are largely found in relatively shallow waters, typically at depths less than 10 m ( 33 foot ), [ 3 ] and occasionally less than 1 thousand ( 3.3 foot ). [ 56 ] Young prefer very shoal places and are often found in water merely 25 curium ( 10 in ) deep. [ 4 ] Sawfish can occur offshore, but are rare deeper than 100 thousand ( 330 foot ). [ 3 ] An nameless sawfish ( either a largetooth or smalltooth sawfish ) was captured off Central America at a astuteness in excess of 175 megabyte ( 575 foot ). [ 59 ] The dwarf and largetooth sawfish are strictly warm-water species that broadly live in waters that are 25–32 °C ( 77–90 °F ) and 24–32 °C ( 75–90 °F ) respectively. [ 51 ] [ 55 ] The green and smalltooth sawfish besides occur in cold waters, in the latter down to 16–18 °C ( 61–64 °F ), as illustrated by their ( master ) distributions that ranged further north and south of the strictly warm-water species. [ 55 ] [ 60 ] sawfish are bottom-dwellers, but in enslavement it has been noted that at least the largetooth and green sawfish readily take food from the water surface. [ 55 ] Sawfish are by and large found in places with soft bottoms such as mire or backbone, but may besides occur over unvoiced rocky bottoms or at coral reefs. [ 61 ] They are frequently found in areas with seagrass or mangrove. [ 3 ] Sawsharks are typically found a lot deeper, frequently at depths in excess of 200 m ( 660 foot ), and when shallower by and large in cold subtropical or temperate waters than sawfish. [ 1 ] [ 45 ]

behavior [edit ]

breed and life sentence bicycle [edit ]

relatively little is known about the generative habits of the sawfish, but all species are ovoviviparous with the adult females giving birth to live young once a year or every second year. [ 3 ] In general, males appear to reach sexual adulthood at a slenderly younger old age and smaller size than females. [ 3 ] a far as known, intimate maturity is reached at an age of 7–12 years in Pristis and 2–3 years in Anoxypristis. In the smalltooth and green sawfish this equals a entire length of 3.7–4.15 thousand ( 12.1–13.6 foot ), in the largetooth sawfish at 2.8–3 molarity ( 9.2–9.8 foot ), in the shadow sawfish about 2.55–2.6 m ( 8.4–8.5 foot ), and in the pin down sawfish at 2–2.25 thousand ( 6.6–7.4 foot ). [ 3 ] This means that the generation length is about 4.6 years in the pin down sawfish and 14.6–17.2 years in the remaining species. [ 3 ] Mating involves the male inserting a clasper, organs at the pelvic fins, into the female to fertilize the eggs. [ 33 ] As known from many elasmobranchs, the felt appears to be roughly, with the sawfish much sustaining lacerations from its partner ‘s attend. [ 62 ] however, through familial testing it has been shown that at least the smalltooth sawfish besides can reproduce by parthenogenesis where no male is involved and the offspring are clones of their mother. [ 63 ] [ 64 ] In Florida, United States, it appears that about 3 % of the smalltooth sawfish young are the result of parthenogenesis. [ 65 ] It is speculated that this may be in reply to being unable to find a partner, allowing the females to reproduce anyhow. [ 64 ] [ 65 ] The pregnancy lasts respective months. [ 33 ] There are 1–23 young in each sawfish litter, which are 60–90 cm ( 2–3 foot ) hanker at parentage. [ 3 ] [ 33 ] In the embryo the dais is elastic and it only hardens curtly before parentage. [ 33 ] To protect the mother the saw of the young have a voiced cover, which falls off shortly after birth. [ 66 ] [ 67 ] The whelp grounds are in coastal and estuarine waters. In most species the young generally stay there for the first part of their lives, occasionally moving upriver when there is an addition in salt. [ 51 ] [ 56 ] [ 57 ] [ 68 ] The exception is the largetooth sawfish where the young move upriver into fresh water where they stay for 3–5 years, sometimes a much as 400 kilometer ( 250 secret intelligence service ) from the ocean. [ 59 ] In at least the smalltooth sawfish the young show a degree of web site fidelity, generally staying in the same fairly small area in the first part of their lives. [ 69 ] In the green and gnome sawfish there are indications that both sexes remain in the same overall region throughout their lives with small mixing between the subpopulations. In the largetooth sawfish the males appear to move more freely between the subpopulations, while mothers return to the area where they were born to give birth to their own young. [ 70 ] [ 71 ] The length of the full life of sawfish is labeled with considerable uncertainty. A green sawfish catch as a adolescent lived for 35 years in enslavement, [ 55 ] and a smalltooth sawfish lived for more than 42 years in captivity. [ 72 ] In the narrow sawfish it has been estimated that the life is about 9 years, and in the Pristis sawfish it has been estimated that it varies from about 30 to more than 50 years depending on the claim species. [ 3 ]

Saw and feeding [edit ]

sawfish are predators that feed on fish, crustaceans and mollusk. [ 2 ] Old stories of sawfish attacking bombastic prey such as whales and dolphins by cutting out pieces of flesh are now considered to be myths and not factual. [ 1 ] [ 60 ] Humans are besides far excessively big to be considered potential prey. [ 73 ] In enslavement they are typically fertilize ad libitum or in dress amounts that ( per workweek ) equal 1–4 % of the total weight of the sawfish, but there are indications that captives mature well faster than their wild counterparts. [ 55 ] The dais ( examine ) plays a significant character in both locating the prey and capturing it, which is unique among chew the fat fish. [ 74 ] [ 75 ] The mind and dais contain thousands of sensory organs, the ampulla of Lorenzini, that allow the sawfish to detect and monitor the movements of other organisms by measuring the electric fields they emit. [ 76 ] Electroreception is besides known from some early families of fish. In sawfish the sensational organs are packed most dumbly on the upper- and bottom of the snout, although with minor differences in their position and numbers depending on exact species. [ 76 ] Those on the upperside allow sawfish to create an prototype of the cubic area above it, even in waters of low visibility. [ 74 ] Utilizing their learn as an extend detection device, sawfish are able to “ view ” their stallion surroundings by maintaining a military position low to the seafloor. [ 1 ] It appears that sawfish can detect electric potential prey items through electroreception from a distance of about 40 curium ( 16 in ). [ 5 ] Some waters where sawfish populate are identical murky, limiting the possibility of hunting by sight. [ 71 ] precisely how they use their watch after the prey has been located has been debated, and some eruditeness on the subject has been based on speculations preferably than veridical observations. [ 5 ] [ 75 ] In 2012 it was shown that there are three elementary techniques, informally called “ witness in water ”, “ saw on substrate ” and “ peg ”. [ 75 ] If a prey item such as a fish is located in the open water, the sawfish uses the first method, making a rapid swipe at the prey with its visualize to incapacitate it. It is then brought to the ocean floor and corrode. [ 5 ] [ 55 ] [ 75 ] The “ see on substrate ” is similar, but used on prey at the ocean floor. [ 5 ] [ 75 ] The learn is highly streamlined and when swiped it causes very little water movement. [ 77 ] The final method acting involves pinning the prey against the ocean floor with the bottom of the see, in a manner similar to that seen in guitarfish. [ 5 ] [ 75 ] The “ trap ” is besides used to manipulate the stead of the prey, allowing fish to be swallowed head-first and thus without engaging any possible fin spines. [ 5 ] [ 75 ] The spines of catfish, a coarse prey, have been found imbedded in the snout of sawfish. [ 33 ] Schools of mullets have been observed trying to escape sawfish. [ 78 ] Prey fish are typically swallowed wholly and not cut into minor pieces with the see, [ 33 ] although on juncture one may be split in half during capture by the slashing motion. [ 5 ] Prey option is consequently limited by the size of the mouth. [ 27 ] A 1.3 m ( 4.3 foot ) sawfish had a 33 centimeter ( 13 in ) wolffish in its stomach. [ 71 ]

In the past it has been suggested that sawfish use their see to dig/rake in the buttocks for prey, [ 79 ] but this was not observed during the study in 2012, [ 75 ] or supported by former hydrodynamic studies. [ 77 ] Large sawfish often have rostral teeth with tips that are notably break. [ 35 ]

Saw and self-defense [edit ]

Old stories much describe sawfish as highly dangerous to humans, sinking ships and cutting people in half, but nowadays these are considered myths and not factual. [ 1 ] [ 60 ] Sawfish are actually docile and harmless to humans, except when captured where they can inflict dangerous injuries when defending themselves by thrashing the experience from side-to-side. [ 6 ] [ 16 ] [ 55 ] The go steady is besides used in self-defense against predators such as sharks that may eat sawfish. [ 33 ] In captivity they have been seen using their proverb during fights over hierarchy or food. [ 71 ]

relationship with humans [edit ]

In history, culture and mythology [edit ]

The largetooth sawfish ( primitively Squalus pristis, immediately Pristis pristis ) was among the species described by Carl Linnaeus in Systema Naturae in 1758, [ 21 ] the starting point of modern zoological terminology, but sawfish were already known thousands of years earlier. [ 7 ] sawfish were occasionally mentioned in ancientness equally much as 1800–2400 years ago, [ 4 ] in works such as Pliny ‘s Natural History ( 77–79 AD ). [ citation needed ] Pristis, the scientific name formalised for sawfish by Linnaeus in 1758, was besides in habit as a name flush before his publication. For example, sawfish or “ priste “ were included in Libri de piscibus marinis in quibus verae piscium effigies expressae sunt by Guillaume Rondelet in 1554, and “ pristi “ were included in De piscibus libri V, et De cetis lib. vnus by Ulisse Aldrovandi in 1613. [ citation needed ] Outside Europe, sawfish are mentioned in previous irani text, such as thirteenth century writings by Zakariya al-Qazwini. [ 4 ] sawfish have been found among archaeological remains in several parts of the world, including the Persian Gulf region, the Pacific slide of Panama, coastal Brazil and elsewhere. [ 4 ] [ 80 ] The cultural significance of sawfish varies importantly. The Aztecs in what is presently Mexico much included depictions of sawfish snout ( power saw ), notably as the striker/sword of the freak Cipactli. [ 81 ] Numerous sawfish rostra have been found buried at the Templo Mayor and two locations in coastal Veracruz had Aztec names referring to sawfish. [ 4 ] In the lapp general region, sawfish teeth have been found in Mayan graves. [ 82 ] The learn of sawfish is separate of the dancing masks of the Huave and Zapotecs in Oaxaca, Mexico. [ 4 ] [ 83 ] The Kuna people on the Caribbean slide of Panama and Colombia considers sawfish as rescuers of drowning people and protectors against dangerous ocean creatures. [ 8 ] besides in Panama sawfish were recognized as containing knock-down spirits that could protect humans against supernatural enemies. [ 8 ] In the Bissagos Islands off West Africa dancing dressed as sawfish and other ocean creatures is separate of men ‘s coming-of-age ceremonies. [ 81 ] [ 84 ] In Gambia the proverb bespeak courage ; the more on display at a sign of the zodiac the more brave the owner. [ 84 ] In Senegal the Lebu people believe the see can protect their family, house and livestock. In the same general area they are recognized as ancestral spirits with the proverb as a magic weapon. The akan people of Ghana see sawfish as an authority symbol. There are proverbs with sawfish in the african speech Duala. [ 85 ] In some other parts of coastal Africa, sawfish are considered highly dangerous and supernatural, but their powers can be used by humans as their experience retains the powers against disease, regretful fortune and evil. [ 85 ] Among most african groups consumption of kernel from sawfish is entirely acceptable, but in a few ( in West Africa the Fula, Serer and Wolof people ) it is taboo. [ 84 ] In the Niger Delta region of southerly Nigeria, the saw of sawfish ( known as oki in Ijaw and neighbor languages ) are often used in masquerades. [ 86 ] In Asia, sawfish are a herculean symbol in many cultures. asian shamans use sawfish rostrums for exorcisms and in other ceremonies to repel demons and disease. [ 87 ] They are believed to protect houses from ghosts when attend over doorways. [ 4 ] Illustrations of sawfish are frequently found at Buddhist temples in Thailand. [ 82 ] In the Sepik region of New Guinea locals admire sawfish, but besides see them as punishers that will unleash big rainstorms on anyone breaking fishing taboo. [ 8 ] Among the Warnindhilyagwa, a group of Indigenous Australians, the ancestral sawfish Yukwurrirrindangwa and rays created the land. The ancestral sawfish carved out the river of Groote Eylandt with their see. [ 8 ] [ 88 ] Among european sailors sawfish were often feared as animals that could sink ships by piercing/sawing in the hull with their visit ( claims immediately known to be wholly false ), [ 60 ] but there are besides stories of them saving people. In one case it was described how a ship about sank during a storm in Italy in 1573. The sailors prayed and made it safely ashore where they discovered a sawfish that had “ plugged ” a trap in the ship with its see. A sawfish snout said to be from this heaven-sent consequence is kept at the Sanctuary of Carmine Maggiore in Naples. [ 4 ] 10000 CFA franc Banknote showing a form of sawfish imagination sawfish have been used as symbols in recent history. During World War II, illustrations of sawfish were placed on united states navy ships, and used as symbols by both American and nazi german submarines. [ 8 ] Sawfish served as the emblem of the german U-96 submarine, known for its depiction in Das Boot, and was late the symbol of the 9th submarine Flotilla. The german World War II Kampfabzeichen der Kleinkampfverbände ( Battle Badge of Small Combat Units ) depicted a sawfish. In cartoons and humorous popular culture, the sawfish—particularly its snout ( “ nose ” ) —has been employed as a sort of living tool. Examples of this can be found in Vicke Viking and Fighting Fantasy volume “ Demons of the Deep “. [ citation needed ] A conventionalized sawfish was chosen by the Central Bank of the West african States to appear on coins and banknotes of the CFA currentness. This was ascribable to the fabulous measure representing fecundity and prosperity. The image takes its shape from an Akan and Baoule bronze weight used for exchanges in the commercial trade of gold powder. [ 84 ]

In aquariums [edit ]

sawfish are popular in populace aquariums, but require identical big tanks. In a follow-up of 10 north american and european populace aquariums that kept sawfish, their tanks were all identical large and ranged from about 1,500,000 to 24,200,000 l ( 400,000–6,390,000 US gallon ). [ 55 ] Individuals in public aquariums frequently function as “ ambassadors ” for sawfish and their conservation pledge. [ 90 ] [ 91 ] In captivity they are quite robust, appear to grow faster than their rampantly counterparts ( possibly due to coherent access to food ) and individuals have lived for decades, but breeding them has proven difficult. [ 55 ] In 2012, four smalltooth sawfish pups were born at Atlantis Paradise Island in the Bahamas and this remains the only prison term a extremity of this syndicate has been successfully bred in enslavement [ 55 ] [ 89 ] ( abortive breeding attempts had happened earlier at the same facility, including a spontaneous abortion in 2003 ). [ 92 ] Nevertheless, it is hoped that this success may be the first footfall in a captive breeding plan for the threatened sawfish. [ 4 ] It is speculated that seasonal worker variations in body of water temperature, brininess and photoperiod are necessity to encourage breeding. [ 55 ] Artificial insemination, as already has been done in a few prisoner sharks, is besides being considered. [ 93 ] Tracking studies indicate that if sawfish are released to the rampantly after spending a period in captivity ( for exercise, if they outgrow their parade ), they quickly adopt a motion practice alike to that of fully godforsaken sawfish. [ 94 ] Among the five sawfish species, alone the four Pristis species are known to be kept in populace aquariums. The most common is the largetooth sawfish with studbooks including 16 individuals in North America in 2014, 5 individuals in Europe in 2013 and 13 individuals in Australia in 2017, followed by the green sawfish with 13 individuals in North America and 6 in Europe. [ 55 ] Both these species are besides kept at public aquariums in Asia and the entirely captive dwarf sawfish are in Japan. [ 95 ] In 2014, studbooks included 12 smalltooth sawfish in North America, [ 55 ] and the only keep elsewhere are at a public aquarium in Colombia. [ 95 ]

descent and conservation [edit ]

sawfish were once common, with habitat found along the coastline of 90 countries, [ 96 ] locally even abundant, [ 4 ] [ 7 ] but they have declined drastically and are immediately among the most threaten groups of marine fish. [ 3 ]

Fishing for versatile uses [edit ]

sawfish and their parts have been used for numerous things. In approximate order of impingement, the four most serious threats today are use in shark fin soup, as traditional medicine, rostral dentition for cockfighting spurs and the meet as a freshness item. [ 4 ] Despite being rays preferably than sharks, [ 2 ] sawfish have some of most respect fins for consumption in shark fin soup, on level with tiger, mako, amobarbital sodium, porbeagle, thresher, hammerhead, blacktip, sandbar and bullshit shark. [ 97 ] As traditional medicine ( specially chinese music, but besides known from Mexico, Brazil, Kenya, Eritrea, Yemen, Iran, India and Bangladesh ) sawfish parts, petroleum or powder have been claimed to work against respiratory ailments, center problems, rheumatoid arthritis, annoyance, inflammation, scabies, peel ulcers, diarrhea and stomach problems, but there is no evidence supporting any of these uses. [ 4 ] The saw are used in ceremonies and as curiosities. Until relatively recently many saws were sold to visiting tourists, or through antique stores or beat shops, but they are now largely sold on-line, much illegally. [ 4 ] In 2007 it was estimated that the fins and see from a single sawfish potentially could earn a fisher more than US $ 5,000 in Kenya and in 2014 a individual rostral tooth sold as cockfighting spurs in Peru or Ecuador had a value of up to US $ 220. [ 4 ] secondary uses are the meat for consumption and the bark for leather. [ 4 ] historically the saw were used as weapons ( large saw ) and combs ( small saw ). [ 88 ] petroleum from the liver-colored was prized for use in gravy boat repairs and street lights, [ 98 ] and ampere late as the 1920s in Florida it was regarded as the best pisces petroleum for consumption. [ 4 ] sawfish fishing goes back respective thousand years, [ 7 ] but until relatively recently it typically involve traditional low-intensity methods such as simpleton hook-and-line or spear. In most regions the major population decline in sawfish started in the 1960s–1980s. [ 7 ] [ 84 ] [ 98 ] This coincided with a major growth in demand of fins for shark fin soup, the expansion of the external shark finning fishing fleet, [ 84 ] and a proliferation of modern nylon fishing nets. [ 98 ] The exception is the dwarf sawfish which was relatively widespread in the Indo-Pacific, but by the early 1900s it had already disappeared from most of its scope, only surviving for certain in Australia ( there is a single holocene possible record from the arabian region ). [ 3 ] [ 99 ] The attend has been described as sawfish ‘s Achilles ‘ heel, as it well becomes entangled in fishing nets. [ 100 ] Sawfish can besides be difficult or dangerous to release from nets, meaning that some fishers will kill them even before bringing them aboard the gravy boat, [ 56 ] or cut off the attend to keep it/release the fish. Because it is their main hunt device, the long-run survival of saw-less sawfish is highly questionable. [ 101 ] In Australia where sawfish have to be released if caught, the narrow sawfish has the highest deathrate rate, [ 68 ] but it is still about 50 % for dwarf sawfish catch in gill nets. [ 99 ] In an attack of lowering this, a guide to sawfish publish has been published. [ 102 ]

Habitat end and vulnerability to predators [edit ]

Although fishing is the main cause of the drastic worsen in sawfish, another serious problem is habitat end. Coastal and estuarine habitats, including mangrove and seagrass meadows, are frequently degraded by human developments and contamination, and these are crucial habitats for sawfish, particularly their young. [ 4 ] [ 103 ] In a study of juvenile sawfish in Western Australia ‘s Fitzroy River about 60 % had bite marks from bull sharks or crocodiles. [ 104 ] Changes to river flows, such as by dams or droughts, can increase the risk faced by sawfish young by bringing them into more reach with predators. [ 69 ] [ 105 ] [ 106 ]

twenty-first century condition [edit ]

The combined image of the five sawfish species encompassed 90 countries, but nowadays they have surely disappeared entirely from 20 of these and possibly disappeared from several others. [ 3 ] Many more have lost at least one of their species, leaving entirely one or two remaining. [ 3 ] Of the five species of sawfish, three are critically endangered and two are endangered according to the International Union for Conservation of Nature ‘s Red list of threaten Species. [ 107 ] The sawfish is now presume extinct in 55 nations ( including China, Iraq, Haiti, Japan, Timor-Leste, EL Salvador, Taiwan, Djibouti and Brunei ), with 18 countries with at least one species of sawfish lacking and 28 countries with at least two. [ 107 ] The United States and Australia appear to be the last strongholds of the species, where sawfish are beneficial protected. [ 107 ] Science Advances identifies Cuba, Tanzania, Colombia, Madagascar, Panama, Brazil, Mexico and Sri Lanka as the nations where pressing action could make a big contribution to saving the species. [ 107 ]

Australia [edit ]

The only remaining stronghold of the four species in the Indo-Pacific area ( specialize, dwarf, largetooth and green sawfish ) is in Northern Australia, but they have besides experienced a decline there. [ 4 ] [ 71 ] Pristis sawfish are protected in Australia and only autochthonal Australians can legally catch them. [ 103 ] [ 108 ] Violations can result in a fine of up to AU $ 121,900. [ 13 ] The narrow sawfish does not receive the like grade of protection as the Pristis sawfish. [ 103 ] [ 109 ] Under CITES regulations, Australia was the only nation that could export wild-caught sawfish for the aquarium deal from 2007 to 2013 ( no nation afterwards ). [ 21 ] This strictly involved the largetooth sawfish where the australian population remains relatively robust, and only live individuals “ to appropriate and satisfactory aquarium for primarily conservation purposes ”. [ 21 ] Numbers traded were very first gear ( eight between 2007 and 2011 ), [ 4 ] and following a review Australia did not export any after 2011. [ 21 ] Largetooth sawfish have been monitored in Fitzroy River, Western Australia, a primary stronghold for the species, since 2000. In December 2018, the largest commemorate mass pisces end in the river occurred when more than 40 sawfish died, chiefly because of heat and a dangerous miss of rain during a poor wet temper. [ 106 ] A 14-day research expedition in Far North Queensland in October 2019 did not spot a single sawfish. Expert Dr Peter Kyne of Charles Darwin University said that habitat change in the south and gillnet fishing in the north had contributed to the decline in numbers, but now that fishers had started working with the conservationists, dams and water diversions to the river flows had become a bigger problem in the north. besides, impact of successful seawater crocodile conservation is a negative one on sawfish populations. however, there were still good populations in the Adelaide River and Daly River in the Northern Territory, and the Fitzroy River in the Kimberley. [ 110 ] A study by Murdoch University researchers and Indigenous rangers, which captured more than 500 sawfish between 2002 and 2018, concluded that the survival of the sawfish could be at risk from dams or major water system diversions on the Fitzroy River. It found that the pisces are wholly reliant on the Kimberley ‘s besotted season floods to complete their breeding cycle ; in recent dry years, the population has suffered. There has been argue about using water from the river for farming and to grow fodder crops for cattle in the region. [ 111 ] Sharks and Rays Australia ( SARA ) are conducting a citizen skill investigation to understand the sawfish ‘s historical habitats. Citizen can report their sawfish sighting on-line. [ 112 ]

Rest of the world [edit ]

Except for Australia, sawfish have been extirpated or only outlive in very abject numbers in the Indo-Pacific region. For case, among the four species only two ( narrow and largetooth sawfish ) surely survive in South Asia, and only two ( narrow-minded and park sawfish ) surely survive in Southeast Asia. [ 3 ] The status of the two species of the Atlantic region, the smalltooth and largetooth sawfish, is comparable to the Indo-Pacific. For example, sawfish have been wholly extirpated from most of the Atlantic coast of Africa ( entirely survives for certain in Guinea-Bissau and Sierra Leone ), vitamin a well as South Africa. [ 3 ] [ 113 ] The merely relatively large remaining population of the largetooth sawfish in the Atlantic area is at the Amazon estuary in Brazil, but there are smaller in Central America and West Africa, and this species is besides found in the Pacific and amerind Oceans. [ 114 ] The smalltooth sawfish is lone found in the Atlantic region and it is possibly the most threaten of all the species, as it had the smallest original roll ( range c. 2,100,000 km2 or 810,000 sq secret intelligence service ) and has experienced the greatest contraction ( disappeared from c. 81 % of its original range ). [ 4 ] It only survives for certain in six countries, [ 115 ] and it is possible that the only remaining feasible population is in the United States. [ 100 ] In the United States the smalltooth sawfish once occurred from Texas to New York, but its numbers have declined by at least 95 % and today it is basically restricted to Florida. [ 116 ] [ 117 ] however, the Florida population retains a high genetic diversity, [ 116 ] has now stabilised and appears to be lento increasing. [ 82 ] [ 117 ] A Recovery plan for the smalltooth sawfish has been in consequence since 2002. [ 103 ] It has been strictly protected in the United States since 2003 when it was added to the Endangered Species Act as the first marine pisces. [ 118 ] This makes it “ illegal to harm, harass, hook, or net sawfish in any way, except with a license or in a allow fishery ”. [ 14 ] The ticket is up to US $ 10,000 for the beginning irreverence alone. [ 14 ] If by chance caught, the sawfish has to be released a cautiously as potential and a basic how-to usher has been published. [ 14 ] In 2003 an try of adding the largetooth sawfish to the Endangered Species Act was denied, in part because this species does not occur in the United States anymore [ 118 ] ( death confirmed US record in 1961 ). [ 114 ] however, it was added in 2011, [ 119 ] and all the remaining sawfish species were added in 2014, restricting deal in them and their parts in the United States. [ 36 ] In 2020, a Florida fisherman used a world power examine to remove a smalltooth sawfish ’ s snout and then released the maimed fish ; he received a fine, community service and probation. [ 120 ] smalltooth sawfish briefly captured for tagging as part of a conservation project Since 2007, all sawfish species have been listed on CITES Appendix I, which prohibits international barter in them and their parts. [ 11 ] [ 12 ] [ 121 ] The alone exception was the relatively robust australian population of the largetooth sawfish that was listed on CITES Appendix II, which allowed trade to public aquariums entirely. [ 11 ] Following reviews Australia did not use this option after 2011 and in 2013 it excessively was moved to Appendix I. [ 21 ] In summation to Australia and the United States, sawfish are protected in the European Union, Mexico, Nicaragua, Costa Rica, Ecuador, Brazil, Indonesia, Malaysia, Bangladesh, India, Pakistan, Bahrain, Qatar, the United Arab Emirates, Guinea, Senegal and South Africa, but they are probably already functionally extirpated or wholly extirpated from several of these countries. [ 3 ] [ 7 ] [ 122 ] [ 123 ] Illegal fish continues and in many countries enforcement of fishing laws is lacking. [ 3 ] [ 21 ] even in Australia where relatively well-protected, people are occasionally caught illegally trying to sell sawfish parts, particularly the saw. [ 13 ] The see is distinctive, but it can be difficult to identify flesh or fins as originating from sawfish when cut up for sale at pisces markets. This can be resolved with DNA testing. [ 124 ] If protected their relatively first gear replica rates make these animals particularly slow to recover from overfishing. [ 87 ] An exercise of this is the largetooth sawfish in Lake Nicaragua where once abundant. The population quickly crashed during the 1970s when tens of thousands were caught. It was protected by the nicaraguan government in the early 1980s, but remains rare nowadays. [ 4 ] Nevertheless, there are indications that at least the smalltooth sawfish population may be able to recover at a faster pace than once believed, if well-protected. [ 125 ] uniquely in this kin, the minute sawfish has a relatively fast replica rate ( generation duration about 4.6 years, less than one-third the prison term of the other species ), it has experienced the smallest contraction of its range ( 30 % ) and it is one of only two species considered Endangered quite than critically Endangered by the IUCN. [ 3 ] The early rated as Endangered is the dwarf sawfish, but this primarily reflects that its main worsen happened at least 100 years ago and IUCN ratings are based on the time period of the final three generations ( estimated about 49 years in dwarf sawfish ). [ 3 ] [ 99 ] There are several research projects aimed at sawfish in Australia and North America, but besides a few in other continents. [ 126 ] The Florida Museum of Natural History maintains the International Sawfish Encounter Database where people worldwide are encouraged to report any sawfish encounters, whether it was living or a dais seen for sale in a shop/online. [ 4 ] [ 14 ] [ 82 ] Its data is used by biologists and conservationists for evaluating the habitat, range and abundance of sawfish around the world. [ 4 ] In an attack of increasing the cognition of their predicament the inaugural “ sawfish Day ” was held on 17 October 2017, [ 83 ] [ 127 ] and this was repeated on the same date in 2018. [ 128 ]

See besides [edit ]

Notes [edit ]

  1. ^[1] correct rostral tooth count refers to visible teeth and alveolus ( “ tooth sockets ” ) from lost teeth .

References [edit ]

foster understand [edit ]