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The largetooth sawfish (''Pristis pristis'', syn. ''P. microdon'' and ''P. perotteti'') is a
species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of
sawfish Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish ...
,
family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
Pristidae Sawfish, also known as carpenter sharks, are a family of rays characterized by a long, narrow, flattened rostrum, or nose extension, lined with sharp transverse teeth, arranged in a way that resembles a saw. They are among the largest fish ...
. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined drastically and is now critically endangered. A range of English names have been used for the species, or populations now part of the species, including common sawfish (despite it being far from common today), wide sawfish, freshwater sawfish, river sawfish (less frequently, other sawfish species also occur in freshwater and rivers), Leichhardt's sawfish (after explorer and naturalist
Ludwig Leichhardt Friedrich Wilhelm Ludwig Leichhardt (), known as Ludwig Leichhardt, (23 October 1813 – c. 1848) was a German explorer and naturalist, most famous for his exploration of northern and central Australia.Ken Eastwood,'Cold case: Leichhardt's dis ...
) and northern sawfish.


Taxonomy

The
taxonomy Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. ...
of ''Pristis pristis'' in relations to ''P. microdon'' (claimed range:
Indo-West Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
) and ''P. perotteti'' (claimed range: Atlantic and East Pacific) has historically caused considerable confusion, but evidence published in 2013 revealed that the three are
conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organis ...
, as morphological and genetic differences are lacking.Faria, V. V.; McDavitt, M. T.; Charvet, P.; Wiley, T. R.; Simpfendorfer, C. A.; Naylor, G. J. P. (2013). ''Species delineation and global population structure of Critically Endangered sawfishes (Pristidae).'' Zoological Journal of the Linnean Society 167: 136–164. doi:10.1111/j.1096-3642.2012.00872.x Retrieved 26 August 2013. As a consequence, recent authorities treat ''P. microdon'' and ''P. perotteti'' as synonyms of ''P. pristis''. Based on an analysis of
NADH Nicotinamide adenine dinucleotide (NAD) is a coenzyme central to metabolism. Found in all living cells, NAD is called a dinucleotide because it consists of two nucleotides joined through their phosphate groups. One nucleotide contains an aden ...
-2 genes there are three main clades of ''P. pristis'': Atlantic, Indo-West Pacific and East Pacific. Its scientific name ''Pristis'' (both the genus and specific name) is derived from the Greek word for saw.


Description

The largetooth sawfish possibly reaches up to in total length, but the largest confirmed was a West African individual that was long. An individual caught in 1951 at Galveston, Texas, which was documented on film but not measured, has been estimated to be of similar size. Today most individuals are far smaller and a typical length is . Large individuals may weigh as much as , or possibly even more. The largetooth sawfish is easily recognized by the forward position of the
dorsal fin A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through c ...
with its leading edge placed clearly in front of the leading edge of the pelvic fins (when the sawfish is seen from above or the side), the relatively long
pectoral fin Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as ...
s with angular tips, and the presence of a small lower tail lobe. In all other sawfish species the leading edge of their dorsal fin is placed at, or behind, the leading edge of the pelvic fins, and all other ''
Pristis ''Pristis'' is a genus of sawfish of the family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maint ...
'' sawfish species have shorter pectoral fins with less pointed tips and lack a distinct lower tail lobe (very small or none). The
rostrum Rostrum may refer to: * Any kind of a platform for a speaker: **dais **pulpit * Rostrum (anatomy), a beak, or anatomical structure resembling a beak, as in the mouthparts of many sucking insects * Rostrum (ship), a form of bow on naval ships * Ros ...
("saw") of the largetooth sawfish has a width that is 15–25% of its length, which is relatively wide compared to the other sawfish species, and there are 14–24 equally separated teeth on each side of it. On average, females have shorter rostrums with fewer teeth than males. The proportional rostrum length also varies with age, with average being around 27% of the total length of the fish, but can be as high as 30% in juveniles and as low as 20–22% in adults. Its upperparts are generally grey to yellowish-brown, often with a clear yellow tinge to the fins. Individuals in freshwater may have a reddish colour caused by blood suffusion below the skin. The underside is greyish or white.


Distribution and habitat

The largetooth sawfish can be found worldwide in tropical and subtropical coastal regions, but it also enters freshwater and has been recorded in rivers as far as from the sea. Historically, its East Atlantic range was from Mauritania to
Angola , national_anthem = " Angola Avante"() , image_map = , map_caption = , capital = Luanda , religion = , religion_year = 2020 , religion_ref = , coordina ...
. There are old reports (last in the late 1950s or shortly after) from the
Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western Europe, Western and Southern Europe and Anatolia, on the south by North Africa ...
and these have typically been regarded as
vagrants Vagrancy is the condition of homelessness without regular employment or income. Vagrants (also known as bums, vagabonds, rogues, tramps or drifters) usually live in poverty and support themselves by begging, scavenging, petty theft, tempora ...
, but a review of records strongly suggests that this sea had a breeding population. Its West Atlantic range was from
Uruguay Uruguay (; ), officially the Oriental Republic of Uruguay ( es, República Oriental del Uruguay), is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast; while bordering ...
to the Caribbean and the
Gulf of Mexico The Gulf of Mexico ( es, Golfo de México) is an ocean basin and a marginal sea of the Atlantic Ocean, largely surrounded by the North American continent. It is bounded on the northeast, north and northwest by the Gulf Coast of the United ...
. Although there are claimed reports from several Gulf Coast states in the United States, a review indicates that only those from
Texas Texas (, ; Spanish: ''Texas'', ''Tejas'') is a state in the South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2020, it is the second-largest U.S. state by ...
are genuine. Other specimens, notably several claimed to be from
Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...
, were likely imported from other countries. Its East Pacific range was from Peru to
Mazatlán Mazatlán () is a city in the Mexican state of Sinaloa. The city serves as the municipal seat for the surrounding '' municipio'', known as the Mazatlán Municipality. It is located at on the Pacific coast, across from the southernmost tip ...
in Mexico. Historically it was widespread in the Indo-Pacific, ranging from South Africa to the Horn of Africa, India, Southeast Asia and
Northern Australia The unofficial geographic term Northern Australia includes those parts of Queensland and Western Australia north of latitude 26° and all of the Northern Territory. Those local government areas of Western Australia and Queensland that lie p ...
. Its total distribution covered almost , more than any other species of sawfish, but it has disappeared from much of its historical range. The last record taken in the Mediterranean dates back to 1959. Adults are primarily found in
estuaries An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environmen ...
and marine waters to a depth of , but mostly less than . Nevertheless, the species does appear to have a greater affinity for freshwater habitats than the
smalltooth sawfish The smalltooth sawfish (''Pristis pectinata'') is a species of sawfish in the family Pristidae. It is found in shallow tropical and subtropical waters in coastal and estuarine parts of the Atlantic. Reports from elsewhere are now believed to be m ...
(''P. pectinata''), green sawfish (''P. zijsron''), and dwarf sawfish (''P. clavata''). Largetooth sawfish from the population in
Lake Nicaragua Lake Nicaragua or Cocibolca or Granada ( es, Lago de Nicaragua, , or ) is a freshwater lake in Nicaragua. Of tectonic origin and with an area of , it is the largest lake in Central America, the 19th largest lake in the world (by area) and the t ...
appear to spend most, if not all, of their life in freshwater, but tagging surveys indicate that at least some do move between this lake and the sea. Captive studies show that this euryhaline species can thrive long-term in both salt and freshwater, regardless of its age, and that an
acclimation Acclimatization or acclimatisation ( also called acclimation or acclimatation) is the process in which an individual organism adjusts to a change in its environment (such as a change in altitude, temperature, humidity, photoperiod, or pH), a ...
from salt to freshwater is faster than the opposite. In captivity they are known to be agile (even swimming backwards), have an unusual ability to "climb" with the use of the pectoral fins and they can jump far out of the water; a individual jumped to a height of . It has been suggested that this may be adaptions for traversing medium-sized waterfalls and rapids when moving upriver. They are generally found in areas with a bottom consisting of sand, mud or silt. The preferred water temperature is between , and or colder is lethal.


Behavior and life cycle

Sexual maturity is reached at a length of about when 7–10 years old. Breeding is seasonal in this
ovoviviparous Ovoviviparity, ovovivipary, ovivipary, or aplacental viviparity is a term used as a "bridging" form of reproduction between egg-laying oviparous and live-bearing viviparous reproduction. Ovoviviparous animals possess embryos that develop insi ...
species, but the exact timing appears to vary depending on the region. The adult females can breed once every 1–2 years, the gestation period is about five months, and there are indications that mothers return to the region where they were born to give birth to their own young. There are 1–13 (average 7) young in each litter, which are long at birth. They are likely typically born in salt or
brackish Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estu ...
water near river mouths, but move into freshwater where the young spend the first 3–5 years of their life, sometimes as much as upriver. In the Amazon basin the largetooth sawfish has been reported even further upstream, and this mostly involves young individuals that are up to long. Occasionally, young individuals become isolated in freshwater pools during floods and may live there for years. The potential lifespan of the largetooth sawfish is unknown, but four estimates suggested 30 years, 35 years, 44 years, and 80 years. The largetooth sawfish is a predator that feeds on fish, molluscs and crustaceans. The "saw" can be used both to stir up the bottom to find prey and to slash at groups of fish. Sawfish are docile and harmless to humans, except when captured where they can inflict serious injuries when defending themselves with the "saw".


Conservation

As suggested by the alternative name common sawfish, it was once plentiful, but has now declined drastically leading to it being considered a critically endangered species by the IUCN. The main threat is overfishing, but it also suffers from habitat loss. Both their fins (used in
shark fin soup Shark fin soup is a traditional soup or stewed dish served in parts of China, Taiwan, and Southeast Asia. The shark fins provide texture, while the taste comes from the other soup ingredients. It is commonly served at special occasions such as ...
) and "saw" (as novelty items) are highly valuable, and the meat is used as food. Because of the "saw" they are particularly prone to becoming entangled in fishing nets. Historically sawfish were also persecuted for the oil in their liver. In the
Niger Delta The Niger Delta is the delta of the Niger River sitting directly on the Gulf of Guinea on the Atlantic Ocean in Nigeria. It is located within nine coastal southern Nigerian states, which include: all six states from the South South geopolitic ...
region of southern
Nigeria Nigeria ( ), , ig, Naìjíríyà, yo, Nàìjíríà, pcm, Naijá , ff, Naajeeriya, kcg, Naijeriya officially the Federal Republic of Nigeria, is a country in West Africa. It is situated between the Sahel to the north and the Gulf o ...
, sawfish (known as ''oki'' in
Ijaw Ijaw may refer to: *Ijaw people The Izon people or Izon Otu, otherwise known as the Ijaw people due to the historic mispronunciation of the name ''Izon'', are an ethnic group majorly found in the Niger Delta in Nigeria, with significant populatio ...
and neighbouring languages) are traditionally hunted for their saws, which are used in masquerades. The largetooth sawfish has been
extirpated Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...
from many regions where formerly present. Among the 75 countries where recorded historically, it has disappeared from 28 and may have disappeared from another 27, leaving only 20 countries where certainly still present. In terms of area this means that it certainly survives in only 39% of its historical range. Only Australia still has a relatively healthy population of the species and this may be the last remaining population in the entire Indo-Pacific that is of sufficient size to be viable, but even it has experienced a decline. Other places in the Indo-Pacific where still present, even if in very low numbers, are off Eastern Africa, the Indian subcontinent and
Papua New Guinea Papua New Guinea (abbreviated PNG; , ; tpi, Papua Niugini; ho, Papua Niu Gini), officially the Independent State of Papua New Guinea ( tpi, Independen Stet bilong Papua Niugini; ho, Independen Stet bilong Papua Niu Gini), is a country i ...
, and in the East Pacific it survives off Central America, Colombia and northern Peru. Whether it survives anywhere in Southeast Asia is generally unclear, but one was captured in the Philippines in 2014 (a country where otherwise considered extirpated). The species has disappeared from much of its Atlantic range and declined where still present. The likely largest remaining population in this region is in the
Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technolog ...
estuary, but another important population is in the San Juan River system in Central America. It was once abundant in Lake Nicaragua (part of the San Juan River system), but this population rapidly crashed during the 1970s when tens of thousands were caught. It has been protected in
Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest country in Central America, bordered by Honduras to the north, the Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to the west. Managua is the countr ...
since the early 1980s, but remains rare in the lake today, and is now threatened by the planned
Nicaragua Canal The Nicaraguan Canal ( es, Canal de Nicaragua), formally the Nicaraguan Canal and Development Project (also referred to as the Nicaragua Grand Canal, or the Grand Interoceanic Canal) was a proposed shipping route through Nicaragua to connect th ...
. In West Africa, the Bissagos Archipelago has often been considered the last remaining stronghold, but interviews with locals indicate that sawfish now also are rare there. All sawfish species were added to
CITES Appendix I CITES (shorter name for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of intern ...
in 2007, thereby restricting international trade. As the first marine fish, there was an attempt of having it listed under the Endangered Species Act (ESA) in 2003 by the United States
National Marine Fisheries Service The National Marine Fisheries Service (NMFS), informally known as NOAA Fisheries, is a United States federal agency within the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) that is responsible for the ste ...
, but it was declined. However, it was listed as ''P. perotteti'' under the ESA in 2011. Following taxonomic changes, the ESA listing was updated to ''P. pristis'' in December 2014. Sawfish are protected in Australia and the United States where a number of conservation projects have been initiated, but the largetooth sawfish has probably already been extirpated from the latter country (last confirmed record in 1961 from Nueces, Texas). Additionally it receives a level of protection in
Bangladesh Bangladesh (}, ), officially the People's Republic of Bangladesh, is a country in South Asia. It is the eighth-most populous country in the world, with a population exceeding 165 million people in an area of . Bangladesh is among the mos ...
, Brazil, Guinea, India, Indonesia, Malaysia, Mexico, Nicaragua,
Senegal Senegal,; Wolof: ''Senegaal''; Pulaar: 𞤅𞤫𞤲𞤫𞤺𞤢𞥄𞤤𞤭 (Senegaali); Arabic: السنغال ''As-Sinighal'') officially the Republic of Senegal,; Wolof: ''Réewum Senegaal''; Pulaar : 𞤈𞤫𞤲𞤣𞤢𞥄𞤲𞤣𞤭 ...
and South Africa, but illegal fishing continues, enforcement of fishing laws is often lacking and it has already disappeared from some of these countries. Largetooth sawfish, especially young, are sometimes eaten by crocodiles and large sharks. This species is the most numerous sawfish in
public aquarium A public aquarium (plural: ''public aquaria'' or ''public Water Zoo'') is the aquatic counterpart of a zoo, which houses living aquatic animal and plant specimens for public viewing. Most public aquariums feature tanks larger than those kept b ...
s, but it is often listed under the synonym ''P. microdon''.
Studbook A breed registry, also known as a herdbook, studbook or register, in animal husbandry and the hobby of animal fancy, is an official list of animals within a specific breed whose parents are known. Animals are usually registered by their breeders ...
s included 16 individuals (10 males, 6 females) in North American aquariums in 2014, 5 individuals (3 males, 2 females) in European aquariums in 2013, and 13 individuals (6 males, 7 females) in Australian aquariums in 2017. Others are kept at public aquariums in Asia.


See also

* Threatened rays


Notes


References

{{Taxonbar, from=Q692258, from2=Q1094698
largetooth sawfish The largetooth sawfish (''Pristis pristis'', syn. ''P. microdon'' and ''P. perotteti'') is a species of sawfish, family Pristidae. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined dra ...
Pantropical fish
largetooth sawfish The largetooth sawfish (''Pristis pristis'', syn. ''P. microdon'' and ''P. perotteti'') is a species of sawfish, family Pristidae. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined dra ...
Fish of Nicaragua
largetooth sawfish The largetooth sawfish (''Pristis pristis'', syn. ''P. microdon'' and ''P. perotteti'') is a species of sawfish, family Pristidae. It is found worldwide in tropical and subtropical coastal regions, but also enters freshwater. It has declined dra ...
ESA endangered species