Sawfish
Template:Short description {{#invoke:other uses|otheruses}} Template:Distinguish Template:Automatic taxobox
Sawfish, also known as carpenter sharks, are a family of very large 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 Template:Convert.<ref name=LastWhite2016>Template:Cite book</ref> They are found worldwide in tropical and subtropical regions in coastal marine and brackish estuarine waters, as well as freshwater rivers and lakes. All species are critically endangered.<ref name=Dulvy2014>Template:Cite journal</ref>
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 similar name but a very different appearance.<ref name=Wueringer2009>Template:Cite journal</ref><ref name=Harrison2014>Template:Cite book</ref>
Sawfishes are relatively slow breeders and the females give birth to live young.<ref name=LastWhite2016/> They feed on fish and invertebrates that are detected and captured with the use of their saw.<ref name=SawfishSawUse>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They are generally harmless to humans, but can inflict serious injuries with the saw when captured and defending themselves.<ref name=FishBaseFamily>{{#invoke:Cite taxon|main|fishbase|genus=|species=|subspecies=}}</ref>
Sawfish have been known and hunted for thousands of years,<ref name=Moore2015>Template:Cite journal</ref> and play an important mythological and spiritual role in many societies around the world.<ref name=FloridaFWCCCultural>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Once common, sawfish have experienced a drastic decline in recent decades, and the only remaining strongholds are in Northern Australia and Florida, United States.<ref name=Harrison2014/><ref name=Platt2013>Template:Cite magazine</ref> All five species are rated as Critically Endangered by the International Union for Conservation of Nature (IUCN).<ref name=IUCNFamily>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They are hunted for their fins (shark fin soup), use of parts as traditional medicine, their teeth and saw. They also face habitat loss.<ref name=Harrison2014/> Sawfish have been listed by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 2007, restricting international trade in them and their parts.<ref name=Black2007>Template:Cite news</ref><ref name=CITESappendix>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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 hefty fines.<ref name=Slezak2016>Template:Cite news</ref><ref name=UofFloridaWhyReport>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Taxonomy and etymologyEdit
The scientific names of the sawfish family Pristidae and its type genus Pristis are derived from the Template:Langx.<ref>Template:LSJ</ref><ref name=UoFloridaPristis>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
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 generally subsumed it into Rhinopristiformes, an order that now includes the sawfish family, as well as families containing guitarfish, wedgefish, banjo rays and the like.<ref>Template:Cite book</ref><ref>Template:Cite journal</ref> Sawfish quite resemble guitarfish, except that the latter group lacks a saw, and their common ancestor likely was similar to guitarfish.<ref name=SawfishSawUse/>
Living speciesEdit
The species level taxonomy in the sawfish family has historically caused considerable confusion and was often described as chaotic.<ref name=Moore2015/> Only in 2013 was it firmly established that there are five living species in two genera.<ref name=Harrison2014/><ref name=Faria2013>Template:Cite journal</ref>
Anoxypristis contains a single living species that historically was included in Pristis, but the two genera are morphologically and genetically highly distinct.<ref name=Wueringer2009/><ref>Template:Cite journal</ref> Today Pristis contains four living, valid species divided into two species groups. Three species are in the smalltooth group, and there is only a single in the largetooth group.<ref name=Harrison2014/> Three poorly defined species were formerly 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.<ref name=Faria2013/> As a consequence, recent authorities treat P. microdon and P. perotteti as junior synonyms of P. pristis.<ref name=Dulvy2014/><ref name=IUCNpristis>Template:Cite iucn</ref><ref name=DepEnvPristis>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=PollerspockStraube>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
| Genus and species group | Image | Scientific name | Common names<ref name=IUCNFamily/><ref name=DepEnvPristis/> (most frequently used listed first)<ref name=Harrison2014/> | IUCN status<ref name=IUCNFamily/> | Distribution<ref name=IUCNFamily/> | Main habitats<ref name=IUCNFamily/> | |
|---|---|---|---|---|---|---|---|
| Anoxypristis | File:AnoxypristisCuspidataCSIRO.jpg | Anoxypristis cuspidata (Latham, 1794) |
Narrow sawfish, knifetooth sawfish, pointed sawfish |
File:CR IUCN 3 1.svg Critically endangered | Indo-Pacific | Marine waters, estuaries | |
| Pristis | Smalltooths | File:Pristis clavata (Dwarf sawfish) in Aqua park.png | Pristis clavata Garman, 1906 |
Dwarf sawfish, Queensland sawfish |
File:CR IUCN 3 1.svg Critically endangered | Indo-Pacific | Marine waters, estuaries |
| File:Pristis pectinata SI2.jpg | Pristis pectinata Latham, 1794 |
Smalltooth sawfish | File:CR IUCN 3 1.svg Critically endangered | Atlantic | Marine waters, estuaries | ||
| File:Aquarium Genoa 01.JPG | Pristis zijsron Bleeker, 1851 |
Green sawfish, longcomb sawfish, narrowsnout sawfish, olive sawfish |
File:CR IUCN 3 1.svg Critically endangered | Indo-Pacific | Marine waters, estuaries | ||
| Largetooths | File:2009 Pristis microdon2.JPG | Pristis pristis (Linnaeus, 1758) |
Largetooth sawfish, common sawfish, wide sawfish, freshwater sawfish, river sawfish, Leichhardt's sawfish, northern sawfish |
File:CR IUCN 3 1.svg Critically endangered | Atlantic, Indo-Pacific, East Pacific |
Marine waters, estuaries, rivers, lakes | |
_in_Aqua_park.png){kind=link}
Extinct (fossil) speciesEdit
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In addition to the living sawfish, there are several extinct species that only are known from fossil remains found around the world in all continents.<ref name=FossilworksFamily/> Peyeria from the Cenomanian age (Late Cretaceous) was once considered as the oldest known pristid,<ref name=Wueringer2009/> though it may represent a rhinid rather than a sawfish,<ref name=Seitz2014>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> or probably a junior synonym of the sclerorhynchoid Onchopristis.<ref>Template:Cite journal</ref> Indisputable sawfish genera emerged in the Cenozoic age about 60 million years ago, relatively soon after the Cretaceous–Paleogene mass extinction. Among these are Propristis, a monotypic genus only known from fossil remains, as well as several extinct Pristis species and several extinct Anoxypristis species (both of these genera are also represented by living species).<ref name=Wueringer2009/><ref name=FossilSawfishIntro>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Historically, palaeontologists have not separated Anoxypristis from Pristis.<ref name=Wueringer2009/> In contrast, several additional extinct genera are occasionally listed, including Dalpiazia, Onchopristis, Oxypristis,<ref name=FossilworksFamily>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and Mesopristis,<ref name=FossilSawfishIntro/> but recent authorities generally include the first two genera within Sclerorhynchoidei and the last two are synonyms of Anoxypristis.<ref name=Wueringer2009/><ref>Template:Cite book</ref>
The extinct order Sclerorhynchoidei had long rostra with large denticles similar to sawfishes and sawsharks. This feature was convergently evolved, recently proposed as 'pristification',<ref>Template:Cite journal</ref> and their closest living relatives are actually skates.<ref name="Villalobos-Segura et al. 2019">Template:Cite journal</ref><ref name="Villalobos-Segura et al. 2021a">Template:Cite journal</ref><ref name="Villalobos-Segura et al. 2021b">Template:Cite journal</ref> While they are often called "sawfishes", the more accurate common name for sclerorhynchoids is "sawskates".<ref>Template:Cite journal</ref>
Appearance and anatomyEdit
Sawfish are dull brownish, greyish, greenish or yellowish above,<ref name=LastWhite2016/> but the shade varies and dark individuals can be almost black.<ref name=Kells2015>Template:Cite book</ref> The underside is pale,<ref name=Kells2015/> and typically whitish.<ref name=LastWhite2016/>
SawEdit
The most distinctive feature of sawfish is their saw-like rostrum with a row of whitish teeth (rostral teeth) on either side of it. The rostrum is an extension of the chondrocranium ("skull"),<ref name=Seitz2014/> made of cartilage and covered in skin.<ref name=GovWesternAustralia>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The rostrum length is typically about one quarter to one third of the total length of the fish,<ref name=SawfishSawUse/> but it varies depending on species, and sometimes with age and sex.<ref name=Wueringer2009/> The rostral teeth are not teeth in the traditional sense, but heavily modified dermal denticles.<ref name=Welten2015>Template:Cite journal</ref> The rostral teeth grow in size throughout the life of the sawfish and a tooth is not replaced if it is lost.<ref name=Welten2015/><ref name=Slaughter1968>Template:Cite journal</ref> In Pristis sawfish, the teeth are found along the entire length of the rostrum, but, in adult Anoxypristis, there are no teeth on the basal one-quarter of the rostrum (about one-sixth in juvenile Anoxypristis).<ref name=ESA2014>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=Allen1999>Template:Cite book</ref> The number of teeth varies depending on the species and can range from 14 to 37 on each side of the rostrum.<ref name=LastWhite2016/><ref name=SawfishID>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>Template:Refn It is common for a sawfish to have slightly different tooth counts on each side of its rostrum. (The difference typically does not surpass three.)<ref name=Wiley2008>Template:Cite journal</ref><ref>Template:Cite journal</ref> In some species, females on average have fewer teeth than males.<ref name=Wueringer2009/><ref name=Wiley2008/> Each tooth is peg-like in Pristis sawfish, and flattened and broadly triangular in Anoxypristis.<ref name=LastWhite2016/> A combination of features, including fins and rostrum, are typically used to separate the species,<ref name=LastWhite2016/><ref name=SawfishID/> but it is possible to do it by the rostrum alone.<ref>Template:Cite journal</ref>
Head, body and finsEdit
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Sawfish have a strong shark-like body, a flat underside and a flat head. Pristis sawfish have a rough sandpaper-like skin texture because of the covering of dermal denticles, but in Anoxypristis the skin is largely smooth.<ref name=LastWhite2016/> The mouth and nostrils are placed on the underside of the head.<ref name=LastWhite2016/> There are about 88–128 small, blunt-edged teeth in the upper jaw of the mouth and about 84–176 in the lower jaw (not to be confused with the teeth on the saw). These are arranged in 10–12 rows on each jaw,<ref name=UofFloridaBiology>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and somewhat resemble a cobblestone road.<ref name=SawfishCSanatomy>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> They have small eyes and behind each is a spiracle, which is used to draw water past the gills.<ref name=UofFloridaAnatomy>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The gill slits, five on each side, are placed on the underside of the body near the base of the pectoral fins.<ref name=SawfishCSanatomy/> The position of the gill openings separates them from the superficially similar yet generally much smaller (up to Template:Circa Template:Convert long) sawsharks, in which the slits are on the side of the neck.<ref name=Wueringer2009/><ref name=Compagno2004>Template:Cite book</ref> Unlike sawfish, sawsharks also have a pair of long barbels on the rostrum ("saw").<ref name=Wueringer2009/><ref name=Compagno2004/>
Sawfish have two relatively high and distinct dorsal fins, wing-like pectoral and pelvic fins, and a tail with a distinct upper lobe and a variably sized lower lobe (lower lobe relatively large in Anoxypristis; small to absent in Pristis sawfish).<ref name=LastWhite2016/> The position of the first dorsal fin compared to the pelvic fins varies and is a useful feature for separating some of the species.<ref name=LastWhite2016/> There are no anal fins.<ref name=UofFloridaBiology/>
Like other elasmobranchs, sawfish lack a swim bladder (instead controlling their buoyancy with a large oil-rich liver), and have a skeleton consisting of cartilage.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Males have claspers, a pair of elongated structures used for mating and positioned on the underside at the pelvic fins.<ref name=UofFloridaBiology/> The claspers are small and indistinct in young males.<ref name=SawfishID/>
Their small intestines contain an internal partition shaped like a corkscrew, called a spiral valve, which increases the surface area available for food absorption.Template:Citation needed
SizeEdit
Sawfish are large to very large fish, but the maximum size of each species is generally uncertain. The smalltooth sawfish, largetooth sawfish and green sawfish are among the world's largest fish. They can certainly all reach about Template:Convert in total length and there are reports of individuals larger than Template:Convert, but these are often labeled with some uncertainty.<ref name=LastWhite2016/> Typically reported maximum total lengths of these three are from Template:Convert.<ref name=LastWhite2016/> Large individuals may weigh as much as Template:Convert,<ref name=UoFLoridaPerotteti>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> or possibly even more.<ref name=ReefQuestSize>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=Nunes2016>Template:Cite journal</ref> Old unconfirmed and highly questionable reports of much larger individuals do exist, including one that reputedly had a length of Template:Convert, another that had a weight of Template:Convert, and a third that was Template:Convert long and weighed Template:Convert.<ref name=ReefQuestSize/>
The two remaining species, the dwarf sawfish and narrow sawfish, are considerably smaller, but are still large fish with a maximum total length of at least Template:Convert and Template:Convert respectively.<ref name=LastWhite2016/><ref name=Curtis2012>Template:Cite book</ref> In the past it was often reported that the dwarf sawfish only reaches about Template:Convert, but this is now known to be incorrect.<ref name=DepEnvClavata>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
DistributionEdit
RangeEdit
Sawfish are found worldwide in tropical and subtropical waters.<ref name=Dulvy2014/>
Historically they ranged in the East Atlantic from Morocco to South Africa,<ref>Template:Cite book</ref> and in the West Atlantic from New York (United States)<ref name=Kells2015/> to Uruguay, including the Caribbean and Gulf of Mexico.<ref name=Dulvy2014/> There are old reports (last in the late 1950s or shortly after) from the Mediterranean and these have typically been regarded as vagrants,<ref name=Dulvy2014/> but a review of records strongly suggests that this sea had a breeding population.<ref name=NatGeo2015>Template:Cite magazine</ref> In the East Pacific they ranged from Mazatlán (Mexico) to northern Peru.<ref name=Monte2009>Template:Cite journal</ref> Although the Gulf of California occasionally has been included in their range, the only known Pacific Mexican records of sawfish are from south of its mouth.<ref name=Monte2009/> They were widespread in the western and central 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.<ref name=Dulvy2014/> Today sawfish have disappeared from much of their historical range.<ref name=Dulvy2014/>
HabitatEdit
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Sawfish are primarily found in coastal marine and estuarine brackish waters, but they are euryhaline (can adapt to various salinities) and also found in freshwater.<ref name=LastWhite2016/> The largetooth sawfish, alternatively called the freshwater sawfish, has the greatest affinity for freshwater.<ref name=WhiteDuke2017>Template:Cite book</ref> For example, it has been reported as far as Template:Convert up the Amazon River and in Lake Nicaragua, and its young spend the first years of their life in freshwater.<ref name=IUCNpristis/> In contrast, the smalltooth, green and dwarf sawfish typically avoid pure freshwater, but may occasionally move far up rivers, especially during periods when there is an increased salinity.<ref name=DepEnvClavata/><ref name=DepEnvZijsron>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=SawfishCSpectinata>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> There are reports of narrow sawfish seen far upriver, but these need confirmation and may involve misidentifications of other species of sawfish.<ref name=UoFloridaCuspidata>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Sawfish are mostly found in relatively shallow waters, typically at depths less than Template:Convert,<ref name=Dulvy2014/> and occasionally less than Template:Convert.<ref name=DepEnvZijsron/> Young prefer very shallow places and are often found in water only Template:Convert deep.<ref name=Harrison2014/> Sawfish can occur offshore, but are rare deeper than Template:Convert.<ref name=Dulvy2014/> An unidentified sawfish (either a largetooth or smalltooth sawfish) was captured off Central America at a depth in excess of Template:Convert.<ref name=SawfishCSpristis>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
The dwarf and largetooth sawfish are strictly warm-water species that generally live in waters that are Template:Convert and Template:Convert respectively.<ref name=DepEnvClavata/><ref name=WhiteDuke2017/> The green and smalltooth sawfish also occur in colder waters, in the latter down to Template:Convert, as illustrated by their (original) distributions that ranged further north and south of the strictly warm-water species.<ref name=WhiteDuke2017/><ref name=UniOFloridaMyth>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Sawfish are bottom-dwellers, but in captivity it has been noted that at least the largetooth and green sawfish readily take food from the water surface.<ref name=WhiteDuke2017/> Sawfish are mostly found in places with soft bottoms such as mud or sand, but may also occur over hard rocky bottoms or at coral reefs.<ref name=Seitz2002>Template:Cite journal</ref> They are often found in areas with seagrass or mangrove.<ref name=Dulvy2014/>
Sawsharks are typically found much deeper, often at depths in excess of Template:Convert, and when shallower mostly in colder subtropical or temperate waters than sawfish.<ref name=Wueringer2009/><ref name=Compagno2004/>
BehaviorEdit
Breeding and life cycleEdit
Relatively little is known about the reproductive 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.<ref name=Dulvy2014/> In general, males appear to reach sexual maturity at a slightly younger age and smaller size than females.<ref name=Dulvy2014/> As far as known, sexual 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 total length of Template:Convert, in the largetooth sawfish at Template:Convert, in the dwarf sawfish about Template:Convert, and in the narrow sawfish at Template:Convert.<ref name=Dulvy2014/> This means that the generation length is about 4.6 years in the narrow sawfish and 14.6–17.2 years in the remaining species.<ref name=Dulvy2014/>
Mating involves the male inserting a clasper, organs at the pelvic fins, into the female to fertilize the eggs.<ref name=GovWesternAustralia/> As known from many elasmobranchs, the mating appears to be rough, with the sawfish often sustaining lacerations from its partner's saw.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, through genetic testing it has been shown that at least the smalltooth sawfish also can reproduce by parthenogenesis where no male is involved and the offspring are clones of their mother.<ref name=Lee2015>Template:Cite magazine</ref><ref name=Fields2015>Template:Cite journal</ref> In Florida, United States, it appears that about 3% of the smalltooth sawfish offspring are the result of parthenogenesis.<ref name=Zielinski2015>Template:Cite news</ref> It is speculated that this may be in response to being unable to find a partner, allowing the females to reproduce anyway.<ref name=Fields2015/><ref name=Zielinski2015/>
The pregnancy lasts several months.<ref name=GovWesternAustralia/> There are 1–23 young in each sawfish litter, which are Template:Convert long at birth.<ref name=Dulvy2014/><ref name=GovWesternAustralia/> In the embryos the rostrum is flexible and it only hardens shortly before birth.<ref name=GovWesternAustralia/> To protect the mother the saws of the young have a soft cover, which falls off shortly after birth.<ref>Template:Cite book</ref><ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The pupping 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 increase in salinity.<ref name=DepEnvClavata/><ref name=DepEnvZijsron/><ref name=SawfishCSpectinata/><ref name=IUCNcuspidata>Template:Cite journal</ref> The exception is the largetooth sawfish where the young move upriver into freshwater where they stay for 3–5 years, sometimes as much as Template:Convert from the sea.<ref name=SawfishCSpristis/> In at least the smalltooth sawfish the young show a degree of site fidelity, generally staying in the same fairly small area in the first part of their lives.<ref name=Poulakis2016>Template:Cite journal</ref> In the green and dwarf sawfish there are indications that both sexes remain in the same overall region throughout their lives with little mixing between the subpopulations. In the largetooth sawfish the males appear to move more freely between the subpopulations, while mothers return to the region where they were born to give birth to their own young.<ref name=Feutry2015>Template:Cite journal</ref><ref name=Phillips2015>Template:Cite journal</ref>
The length of the full lifespan of sawfish is labeled with considerable uncertainty. A green sawfish caught as a juvenile lived for 35 years in captivity,<ref name=WhiteDuke2017/> and a smalltooth sawfish lived for more than 42 years in captivity.<ref>Template:Cite news</ref> In the narrow sawfish it has been estimated that the lifespan 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 exact species.<ref name=Dulvy2014/>
ElectrolocationEdit
The rostrum (saw), unique among jawed fish, plays a significant role in both locating and capturing prey.<ref name=ZombieBirds/><ref name=Wueringer2012>Template:Cite journal</ref> The head and rostrum contain thousands of sensory organs, the ampullae of Lorenzini, that allow the sawfish to detect and monitor the movements of other organisms by measuring the electric fields they emit.<ref name=Wueringer2011>Template:Cite journal</ref> Electroreception is found in all cartilaginous fishes and some bony fishes. In sawfish the sensory organs are packed most densely on the upper- and underside of the rostrum, varying in position and numbers depending on the species.<ref name=Wueringer2011/><ref name=ZombieBirds>Template:Cite book</ref> Utilizing their saw as an extended sensing device, sawfish are able to examine their entire surroundings from a position close to the seafloor.<ref name=Wueringer2009/> It appears that sawfish can detect potential prey by electroreception from a distance of about Template:Convert.<ref name=SawfishSawUse/> Some waters where sawfish live are very murky, limiting the possibility of hunting by sight.<ref name=Phillips2015/>
FeedingEdit
Sawfish are predators that feed on fish, crustaceans and molluscs.<ref name=LastWhite2016/> Old stories of sawfish attacking large prey such as whales and dolphins by cutting out pieces of flesh are now considered to be wholly unsubstantiated.<ref name=Wueringer2009/><ref name=UniOFloridaMyth/> Humans are far too large to be considered potential prey.<ref name=UoFloridaBasics>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In captivity they are typically fed ad libitum or in set amounts that (per week) equal 1–4% of the total weight of the sawfish, but there are indications that captives grow considerably faster than their wild counterparts.<ref name=WhiteDuke2017/>
Exactly how they use their saw after the prey has been located has been debated, and some scholarship on the subject has been based on speculations rather than real observations.<ref name=SawfishSawUse/><ref name=Wueringer2012/> In 2012 it was shown that there are three primary techniques, informally called "saw in water", "saw on substrate" and "pin".<ref name=Wueringer2012/> 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 saw to incapacitate it. It is then brought to the seabed and eaten.<ref name=SawfishSawUse/><ref name=WhiteDuke2017/><ref name=Wueringer2012/> The "saw on substrate" is similar, but used on prey at the seabed.<ref name=SawfishSawUse/><ref name=Wueringer2012/> The saw is highly streamlined and when swiped it causes very little water movement.<ref name=AG2017>Template:Cite news</ref> The final method involves pinning the prey against the seabed with the underside of the saw, in a manner similar to that seen in guitarfish.<ref name=SawfishSawUse/><ref name=Wueringer2012/> The "pin" is also used to manipulate the position of the prey, allowing fish to be swallowed head-first and thus without engaging any possible fin spines.<ref name=SawfishSawUse/><ref name=Wueringer2012/> The spines of catfish, a common prey, have been found imbedded in the rostrum of sawfish.<ref name=GovWesternAustralia/> Schools of mullets have been observed trying to escape sawfish.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Prey fish are typically swallowed whole and not cut into small pieces with the saw,<ref name=GovWesternAustralia/> although on occasion one may be split in half during capture by the slashing motion.<ref name=SawfishSawUse/> Prey choice is therefore limited by the size of the mouth.<ref name=Seitz2014/> A Template:Convert sawfish had a Template:Convert catfish in its stomach.<ref name=Phillips2015/>
It had been suggested that sawfish use their saw to dig/rake in the bottom for prey,<ref name=Breeder1952>Template:Cite journal</ref> but this was not observed during a 2012 study,<ref name=Wueringer2012/> or supported by later hydrodynamic studies.<ref name=AG2017/> Large sawfish often have rostral teeth with tips that are notably worn.<ref name=Slaughter1968/>
Saw and self-defenseEdit
Old stories often describe sawfish as highly dangerous to humans, sinking ships and cutting people in half, but today these are considered myths and not factual.<ref name=Wueringer2009/><ref name=UniOFloridaMyth/> Sawfish are actually docile and not aggressive to humans and only use their saws against people defensively such as when captured; they can inflict serious injuries when defending themselves, by thrashing the saw from side to side.<ref name=FishBaseFamily/><ref name=UoFloridaPristis/><ref name=WhiteDuke2017/> The saw is also used in self-defense against predators, such as sharks, that may eat sawfish.<ref name=GovWesternAustralia/> In captivity, they have been seen using their saws during fights over hierarchy or food.<ref name=Phillips2015/>
Relationship with humansEdit
In history, culture and mythologyEdit
The largetooth sawfish was among the species formally described by Carl Linnaeus (as "Squalus pristis") in Systema Naturae in 1758,<ref name=IUCNpristis/> but sawfish were already known thousands of years earlier.<ref name=Moore2015/>
Sawfish were occasionally mentioned in antiquity, in works such as Pliny's Natural History (77–79 AD).<ref name=Harrison2014/> Pristis, the scientific name formalised for sawfish by Linnaeus in 1758, was also in use as a name even 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. Outside Europe, sawfish are mentioned in old Persian texts, such as 13th century writings by Zakariya al-Qazwini.<ref name=Harrison2014/>
Sawfish have been found among archaeological remains in several parts of the world, including the Persian Gulf region, the Pacific coast of Panama, coastal Brazil and elsewhere.<ref name=Harrison2014/><ref name=Gonzalez2005>Template:Cite journal</ref>
The cultural significance of sawfish varies significantly. The Aztecs, in what is currently Mexico, often included depictions of sawfish rostra (saws), notably as the striker/sword of the monster Cipactli.<ref name=Eilperin2012>Template:Cite book</ref> Numerous sawfish rostra have been found buried at the Templo Mayor, and two locations in coastal Veracruz had Aztec names referring to sawfish.<ref name=Harrison2014/> In the same general region, sawfish teeth have been found in Mayan graves.<ref name=Sohn2015>Template:Cite journal</ref> The sawfish saw is part of the dancing masks of the Huave and Zapotecs in Oaxaca, Mexico.<ref name=Harrison2014/><ref name=SaveOSSawfishCultural>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> The Guna people on the Caribbean coast of Panama and Colombia consider sawfish as rescuers of drowning people, and protectors against dangerous sea creatures.<ref name=FloridaFWCCCultural/> Also in Panama, sawfish were recognized as containing powerful spirits that could protect humans against supernatural enemies.<ref name=FloridaFWCCCultural/>
In the Bissagos Islands off West Africa, dancing dressed as sawfish and other sea creatures is part of men's coming-of-age ceremonies.<ref name=Eilperin2012/><ref name=Robillard2006>Template:Cite journal</ref> In Gambia, the saws indicate courage; the more saws are on display in a house, the more courageous the owner is seen to be.<ref name=Robillard2006/> In Senegal, the Lebu people believe the saw can protect their family, house and livestock. In the same general region, they are recognized as ancestral spirits who use the saw as a magic weapon. The Akan people of Ghana see sawfish as an authority symbol. There are proverbs with sawfish in the African language Duala.<ref name=Helfman2011>Template:Cite book</ref> In some other parts of coastal Africa, sawfish are considered extremely dangerous and supernatural, but their powers can be used by humans, as their saw is seen to retain powers against disease, bad luck and evil.<ref name=Helfman2011/> Among most African groups, consumption of sawfish meat is entirely acceptable, but among some (the Fula, Serer and Wolof people) it is taboo.<ref name=Robillard2006/> In the Niger Delta region of southern Nigeria, the saws of sawfish (known as oki in Ijaw and neighbouring languages) are often used in masquerades.<ref name="AfricanPast">Template:Cite book</ref>
In Asia, sawfish are a powerful symbol in many cultures. Asian shamans Template:Specify use sawfish rostrums for exorcisms and other ceremonies to repel demons and disease.<ref name=Raloff2007>Raloff, Janet (2007). Hammered Saws Template:Webarchive, Science News vol. 172, pp. 90–92.</ref> They are believed to protect houses from ghosts when hung over doorways.<ref name=Harrison2014/> Illustrations of sawfish are often found at Buddhist temples in Thailand.<ref name=Sohn2015/> In the Sepik region of New Guinea, locals admire sawfish, but also see them as punishers, who will unleash heavy rainstorms on anyone breaking fishing taboos.<ref name=FloridaFWCCCultural/> 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 saws.<ref name=FloridaFWCCCultural/><ref name=McDavitt2005>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Among European sailors, sawfish were often feared as animals that could sink ships by piercing/sawing the hull with their saw (claims now known to be entirely untrue),<ref name=UniOFloridaMyth/> but there are also stories of them saving people. In one case, it was described how a ship almost 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 hole in the ship with its saw. A sawfish rostrum said to be from this miraculous event is kept at the sanctuary of Carmine Maggiore in Naples.<ref name=Harrison2014/>
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Sawfish have been used as symbols in recent history. During World War II, illustrations of sawfish were placed on navy ships, and used as symbols by both American and Nazi German submarines.<ref name=FloridaFWCCCultural/> Sawfish served as the emblem of the German U-96 submarine, known for its portrayal in Das Boot, and was later the symbol of the 9th U-boat Flotilla. The German World War II {{#invoke:Lang|lang}} (Battle Badge of Small Combat Units) depicted a sawfish.
In cartoons and humorous popular culture, the sawfish—particularly its rostrum ("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".Template:Citation needed
A stylized sawfish was chosen by the Central Bank of the West African States to appear on coins and banknotes of the CFA currency. This was due to it being a mythological representation of fecundity and prosperity. The image takes its form from an Akan and Baoule bronze weight, used for exchanges in the trade of gold powder.<ref name=Robillard2006/>
In aquariumsEdit
Sawfish are popular in public aquariums, but require very large tanks. In a review of 10 North American and European public aquariums that kept sawfish, their tanks were all very large and ranged from about Template:Convert.<ref name=WhiteDuke2017/> Individuals in public aquariums often function as "ambassadors" for sawfish and their conservation plight.<ref name=GeorgiaAq/><ref name=Batesman2018>Template:Cite news</ref> In captivity they are quite robust, appear to grow faster than their wild counterparts (perhaps due to consistent access to food). Some individuals have lived for decades, but breeding them has proven difficult.<ref name=WhiteDuke2017/> In 2012, four smalltooth sawfish pups were born at Atlantis Paradise Island in the Bahamas and, in 2023, another three were born at SeaWorld Orlando in Florida; these remain the only times a member of this family has been successfully bred in captivity.<ref name=WhiteDuke2017/><ref name=BahamasLocal2012/><ref name=seaworldorlando>Template:Cite news</ref> Unsuccessful breeding attempts had taken place earlier at the same facility, including a miscarriage in 2003.<ref name=Henningsen2004>Template:Cite book</ref> Nevertheless, it is hoped that this success may be the first step in a captive breeding program for the threatened sawfish.<ref name=Harrison2014/> It is speculated that seasonal variations in water temperature, salinity and photoperiod are necessary to encourage breeding.<ref name=WhiteDuke2017/> Artificial insemination, as already practiced with a few captive sharks, is also being considered.<ref>Template:Cite news</ref> Tracking studies indicate that if sawfish are released to the wild after spending a period in captivity (for example, if they outgrow their exhibit), they rapidly adopt a movement pattern similar to that of fully wild sawfish.<ref>Template:Cite news</ref>
Among the five sawfish species, only the four Pristis species are known to be kept in public 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; this was followed by the green sawfish, with 13 individuals in North America, and 6 in Europe.<ref name=WhiteDuke2017/> Both of these species are also kept at public aquariums in Asia, and the only captive dwarf sawfish are in Japan.<ref name=SawfishAquariums>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In 2014, studbooks included 12 smalltooth sawfish in North America,<ref name=WhiteDuke2017/> and the only ones kept elsewhere are at a public aquarium in Colombia.<ref name=SawfishAquariums/>
Decline and conservationEdit
Sawfish were once common, with habitat found along the coastline of 90 countries,<ref>Template:Cite news</ref> locally even abundant,<ref name=Harrison2014/><ref name=Moore2015/> but they have declined drastically and are now among the most threatened groups of marine fish.<ref name=Dulvy2014/>
Fishing for various usesEdit
Sawfish and their parts have been used for numerous things. In approximate order of impact, the four most serious threats today are use in shark fin soup, as traditional medicine, rostral teeth for cockfighting spurs and the saw as a novelty item.<ref name=Harrison2014/> Despite being rays rather than sharks,<ref name=LastWhite2016/> sawfish have some of most prized fins for use in shark fin soup, on level with tiger, mako, blue, porbeagle, thresher, hammerhead, blacktip, sandbar and bull shark.<ref>Vannuccini, S. 1999. Shark utilization, marketing and trade. Template:Webarchive FAO Fisheries Technical Paper. No. 389. Rome, FAO. Retrieved 17 March 2009.</ref> As traditional medicine (especially Chinese medicine, but also known from Mexico, Brazil, Kenya, Eritrea, Yemen, Iran, India and Bangladesh) sawfish parts, oil or powder have been claimed to work against respiratory ailments, eye problems, rheumatism, pain, inflammation, scabies, skin ulcers, diarrhea and stomach problems, but there is no evidence supporting any of these uses.<ref name=Harrison2014/> The saws are used in ceremonies and as curiosities. Until relatively recently many saws were sold to visiting tourists, or through antique stores or shell shops, but they are now mostly sold online, often illegally.<ref name=Harrison2014/> In 2007 it was estimated that the fins and saw from a single sawfish potentially could earn a fisher more than US$5,000 in Kenya and in 2014 a single rostral tooth sold as cockfighting spurs in Peru or Ecuador had a value of up to US$220.<ref name=Harrison2014/> Secondary uses are the meat for consumption and the skin for leather.<ref name=Harrison2014/> Historically the saws were used as weapons (large saws) and combs (small saws).<ref name=McDavitt2005/> Oil from the liver was prized for use in boat repairs and street lights,<ref name=Reis2016>Template:Cite journal</ref> and as recent as the 1920s in Florida it was regarded as the best fish oil for consumption.<ref name=Harrison2014/>
Sawfish fishing goes back several thousand years,<ref name=Moore2015/> but until relatively recently it typically involved traditional low-intensity methods such as simple hook-and-line or spearing. In most regions the major population decline in sawfish started in the 1960s–1980s.<ref name=Moore2015/><ref name=Robillard2006/><ref name=Reis2016/> This coincided with a major growth in demand of fins for shark fin soup, the expansion of the international shark finning fishing fleet,<ref name=Robillard2006/> and a proliferation of modern nylon fishing nets.<ref name=Reis2016/> 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 range, only surviving for certain in Australia (there is a single recent possible record from the Arabian region).<ref name=Dulvy2014/><ref name=IUCNclavata>Template:Cite iucn</ref> The saw has been described as sawfish's Achilles' heel, as it easily becomes entangled in fishing nets.<ref name=Giglio2016>Template:Cite journal</ref> Sawfish can also be difficult or dangerous to release from nets, meaning that some fishers will kill them even before bringing them aboard the boat,<ref name=DepEnvZijsron/> or cut off the saw to keep it/release the fish. Because it is their main hunting device, the long-term survival of saw-less sawfish is highly questionable.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In Australia where sawfish have to be released if caught, the narrow sawfish has the highest mortality rate,<ref name=IUCNcuspidata/> but it is still almost 50% for dwarf sawfish caught in gill nets.<ref name=IUCNclavata/> In an attempt of lowering this, a guide to sawfish release has been published.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Habitat destruction and vulnerability to predatorsEdit
Although fishing is the main cause of the drastic decline in sawfish, another serious problem is habitat destruction. Coastal and estuarine habitats, including mangrove and seagrass meadows, are often degraded by human developments and pollution, and these are important habitats for sawfish, especially their young.<ref name=Harrison2014/><ref name=SawfishCCConservation>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> In a study of juvenile sawfish in Western Australia's Fitzroy River about 60% had bite marks from bull sharks or crocodiles.<ref name=BBCpredators>Template:Cite news</ref> Changes to river flows, such as by dams or droughts, can increase the risk faced by sawfish young by bringing them into more contact with predators.<ref name=Poulakis2016/><ref>Template:Cite journal</ref><ref name=Moodie2019>Template:Cite news</ref>
Endangered sawfish and other fish in Florida are showing strange behaviors and dying because of environmental toxins. These toxins, produced by microalgae near the sea bottom, affect the neurological systems of fish. <ref>Template:Cite news</ref>
21st century statusEdit
The combined range of the five sawfish species encompassed 90 countries, but today they have certainly disappeared entirely from 20 of these and possibly disappeared from several others.<ref name=Dulvy2014/> Many more have lost at least one of their species, leaving only one or two remaining.<ref name=Dulvy2014/> 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 Threatened Species.<ref name=":0">Template:Cite news</ref> The sawfish is now presumed 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 missing and 28 countries with at least two.<ref name=":0" /> The United States and Australia appear to be the last strongholds of the species, where sawfish are better protected.<ref name=":0" /> Science Advances identifies Cuba, Tanzania, Colombia, Madagascar, Panama, Brazil, Mexico and Sri Lanka as the nations where urgent action could make a big contribution to saving the species.<ref name=":0" />
AustraliaEdit
The only remaining stronghold of the four species in the Indo-Pacific region (narrow, dwarf, largetooth and green sawfish) is in Northern Australia, but they have also experienced a decline there.<ref name=Harrison2014/><ref name=Phillips2015/> Pristis sawfish are protected in Australia and only Indigenous Australians can legally catch them.<ref name=SawfishCCConservation/><ref name=DeptEnvWaHe2010>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> Violations can result in a fine of up to AU$121,900.<ref name=Slezak2016/> The narrow sawfish does not receive the same level of protection as the Pristis sawfish.<ref name=SawfishCCConservation/><ref>Template:Cite news</ref> Under CITES regulations, Australia was the only country that could export wild-caught sawfish for the aquarium trade from 2007 to 2013 (no country afterwards).<ref name=IUCNpristis/> This strictly involved the largetooth sawfish where the Australian population remains relatively robust, and only living individuals "to appropriate and acceptable aquaria for primarily conservation purposes".<ref name=IUCNpristis/> Numbers traded were very low (eight between 2007 and 2011),<ref name=Harrison2014/> and following a review Australia did not export any after 2011.<ref name=IUCNpristis/>
Largetooth sawfish have been monitored in Fitzroy River, Western Australia, a primary stronghold for the species, since 2000. In December 2018, the largest recorded mass fish death in the river occurred when more than 40 sawfish died, mainly because of heat and a severe lack of rainfall during a poor wet season.<ref name=Moodie2019/> 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. Also, impact of successful saltwater 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.<ref>Template:Cite news</ref>
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 diversions on the Fitzroy River. It found that the fish are completely reliant on the Kimberley's wet season floods to complete their breeding cycle; in recent drier years, the population has suffered. There has been debate about using water from the river for agriculture and to grow fodder crops for cattle in the region.<ref>Template:Cite news</ref>
Sharks and Rays Australia (SARA) are conducting a citizen science investigation to understand the sawfish's historical habitats. Citizen can report their sawfish sighting online.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Rest of the worldEdit
Except for Australia, sawfish have been extirpated or only survive in very low numbers in the Indo-Pacific region. For example, among the four species only two (narrow and largetooth sawfish) certainly survive in South Asia, and only two (narrow and green sawfish) certainly survive in Southeast Asia.<ref name=Dulvy2014/>
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 entirely extirpated from most of the Atlantic coast of Africa (only survives for certain in Guinea-Bissau and Sierra Leone), as well as South Africa.<ref name=Dulvy2014/><ref name=Everett2015>Template:Cite journal</ref> The only relatively large remaining population of the largetooth sawfish in the Atlantic region is at the Amazon estuary in Brazil, but there are smaller in Central America and West Africa, and this species is also found in the Pacific and Indian Oceans.<ref name=Fernandez2013>Template:Cite journal</ref> The smalltooth sawfish is only found in the Atlantic region and it is possibly the most threatened of all the species, as it had the smallest original range (range Template:Circa Template:Convert) and has experienced the greatest contraction (disappeared from c. 81% of its original range).<ref name=Harrison2014/> It only survives for certain in six countries,<ref name=IUCNpectinata>Template:Cite journal</ref> and it is possible that the only remaining viable population is in the United States.<ref name=Giglio2016/> 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 essentially restricted to Florida.<ref name=Chapman2011>Template:Cite journal</ref><ref name=RecoveryPlanSmalltooth>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> However, the Florida population retains a high genetic diversity,<ref name=Chapman2011/> has now stabilised and appears to be slowly increasing.<ref name=Sohn2015/><ref name=RecoveryPlanSmalltooth/> A Recovery Plan for the smalltooth sawfish has been in effect since 2002.<ref name=SawfishCCConservation/> It has been strictly protected in the United States since 2003 when it was added to the Endangered Species Act as the first marine fish.<ref name=NationalGeographic2003>Template:Cite magazine</ref> This makes it "illegal to harm, harass, hook, or net sawfish in any way, except with a permit or in a permitted fishery".<ref name=UofFloridaWhyReport/> The fine is up to US$10,000 for the first violation alone.<ref name=UofFloridaWhyReport/> If accidentally caught, the sawfish has to be released as carefully as possible and a basic how-to guide has been published.<ref name=UofFloridaWhyReport/> In 2003 an attempt 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<ref name=NationalGeographic2003/> (last confirmed US record in 1961).<ref name=Fernandez2013/> However, it was added in 2011,<ref name=ESA2011>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and all the remaining sawfish species were added in 2014, restricting trade in them and their parts in the United States.<ref name=ESA2014/> In 2020, a Florida fisherman used a power saw to remove a smalltooth sawfish's rostrum and then released the maimed fish; he received a fine, community service and probation.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
Since 2007, all sawfish species have been listed on CITES Appendix I, which prohibits international trade in them and their parts.<ref name=Black2007/><ref name=CITESappendix/><ref name=CITESprop17>Template:Cite conference</ref> The only exception was the relatively robust Australian population of the largetooth sawfish that was listed on CITES Appendix II, which allowed trade to public aquariums only.<ref name=Black2007/> Following reviews Australia did not use this option after 2011 and in 2013 it too was moved to Appendix I.<ref name=IUCNpristis/> In addition 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 likely already functionally extirpated or entirely extirpated from several of these countries.<ref name=Dulvy2014/><ref name=Moore2015/><ref name=Fordham2018>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref><ref name=Casselman2019>Template:Cite magazine</ref> Illegal fishing continues and in many countries enforcement of fishing laws is lacking.<ref name=Dulvy2014/><ref name=IUCNpristis/> Even in Australia where relatively well-protected, people are occasionally caught illegally trying to sell sawfish parts, especially the saw.<ref name=Slezak2016/> The saw is distinctive, but it can be difficult to identify flesh or fins as originating from sawfish when cut up for sale at fish markets. This can be resolved with DNA testing.<ref name=Palmeira2013>Template:Cite journal</ref> If protected their relatively low reproduction rates make these animals especially slow to recover from overfishing.<ref name=Raloff2007/> An example of this is the largetooth sawfish in Lake Nicaragua where once abundant. The population rapidly crashed during the 1970s when tens of thousands were caught. It was protected by the Nicaraguan government in the early 1980s, but remains rare today.<ref name=Harrison2014/> Nevertheless, there are indications that at least the smalltooth sawfish population may be able to recover at a faster pace than formerly believed, if well-protected.<ref name=Williams2018>Template:Cite news</ref> Uniquely in this family, the narrow sawfish has a relatively fast reproduction rate (generation length about 4.6 years, less than one-third the time of the other species), it has experienced the smallest contraction of its range (30%) and it is one of only two species considered Endangered rather than Critically Endangered by the IUCN.<ref name=Dulvy2014/> The other rated as Endangered is the dwarf sawfish, but this primarily reflects that its main decline happened at least 100 years ago and IUCN ratings are based on the time period of the last three generations (estimated about 49 years in dwarf sawfish).<ref name=Dulvy2014/><ref name=IUCNclavata/>
There are several research projects aimed at sawfish in Australia and North America, but also a few in other continents.<ref name=SawfishCSResearch>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> 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 rostrum seen for sale in a shop/online.<ref name=Harrison2014/><ref name=UofFloridaWhyReport/><ref name=Sohn2015/> Its data is used by biologists and conservationists for evaluating the habitat, range and abundance of sawfish around the world.<ref name=Harrison2014/> In an attempt of increasing the knowledge of their plight the first "Sawfish Day" was held on 17 October 2017,<ref name=SaveOSSawfishCultural/><ref name=RipleysAqCelebratingSawfish>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref> and this was repeated on the same date in 2018.<ref>{{#invoke:citation/CS1|citation |CitationClass=web }}</ref>
See alsoEdit
NotesEdit
ReferencesEdit
Further readingEdit
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- Sawfish Australian Marine Conservation Society
- Report your sawfish sighting to Sharks and Rays Australia
External linksEdit
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