2016-12-20

Langfin mako shairk addit tae category

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{{Taxobox

| name = Langfin mako shairk

| image = Isurus paucus.jpg

| image_width = 240 px

| image2 = Long fin mako shark.svg

| status = VU

| status_system = IUCN3.1

| status_ref =<ref name="iucn">{{IUCN2008 |assessor=Reardon, M.B. |assessor2=Gerber, L. |assessor3=Cavanagh, R.D. |last-assessor-amp=yes |year=2006 |id=60225 |title=Isurus paucus |downloaded=December 25, 2008}}</ref>

| regnum = [[Animal]]ia

| phylum = [[Chordate|Chordata]]

| classis = [[Chondrichthyes]]

| subclassis = [[Elasmobranchii]]

| superordo = [[Shairk|Selachimorpha]]

| ordo = [[Lamniformes]]

| familia = [[Lamnidae]]

| genus = ''[[Isurus]]''

| species = '''''I. paucus'''''

| range_map = Cypron-Range Isurus paucus.svg

| range_map_width = 240px

| range_map_caption = Range of the longfin mako shark

| binomial = ''Isurus paucus''

| binomial_authority = [[Darío Guitart-Manday|Guitart-Manday]], 1966

| synonyms = ''Isurus alatus'' <small>Garrick, 1967</small>

''Lamiostoma belyaevi '' <small>Glückman, 1964 </small>

''Isurus oxyrinchus '' <small>(non Rafinesque, 1810) misapplied</small>

}}

The '''longfin mako shark''' (''Isurus paucus'') is a [[species]] of [[Lamniformes|mackerel shairk]] in the faimily [[Lamnidae]], wi a probable warldwide distribution in [[temperate]] an [[tropical]] watters. An uncommon species, it is teepically lumpit thegither unner the name "[[Isurus|mako]]" wi its better-kent relative, the [[shortfin mako shark]] (''I. oxyrinchus''). The langfin mako is a pelagic species foond in moderately deep watter, haein been reportit tae a deth o {{convert|220|m|ft|abbr=on}}. Growin tae a maximum lenth o {{convert|4.3|m|ft|abbr=on}}, the slimmer build an lang, broad [[pectoral fin]]s o this shairk suggest that it is a slawer an less active soummer than the shortfin mako.

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Longfin mako sharks are [[predator]]s that feed on small [[shoaling and schooling|schooling]] [[bony fish]]es and [[cephalopod]]s. Whether this shark is capable of elevating its body temperature above that of the surrounding water like the other members of its family is uncertain, though it possesses the requisite physiological adaptations. Reproduction in this species is [[aplacental viviparous]], meaning the [[embryo]]s hatch from eggs inside the [[uterus]]. In the later stages of development, the unborn young are fed nonviable eggs by the mother ([[oophagy]]). The litter size is typically two, but may be as many as eight. The longfin mako is of limited [[commercial fishing|commercial value]], as its meat and fins are of lower quality than those of other pelagic sharks; it is caught unintentionally in low numbers across its range. The [[International Union for Conservation of Nature]] has assessed this species as [[vulnerable species|vulnerable]] due to its rarity, low reproductive rate, and continuing [[bycatch]] mortality.

==Taxonomy and phylogeny==

The original description of the longfin mako was published in 1966 by Cuban marine scientist Darío Guitart-Manday, in the scientific journal ''Poeyana'', based on three adult specimens from the [[Caribbean Sea]]. An earlier [[synonym (taxonomy)|synonym]] of this species may be ''Lamiostoma belyaevi'', described by Glückman in 1964. However, the [[type specimen]] designated by Glückman consists of a set of [[fossil]] teeth that could not be confirmed as belonging to the longfin mako, thus the name ''paucus'' took precedence over ''belyaevi'' despite being published later.<ref name="compagno">{{cite book |author=Compagno, L.J.V. |year=2002 |title=Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date (Volume 2) |place=Rome |publisher=Food and Agriculture Organization |pages=115–117 |isbn=92-5-104543-7}}</ref> The [[specific name (zoology)|specific epithet]] ''paucus'' is [[Latin]] for "few", referring to the rarity of this species relative to the shortfin mako.<ref name="ebert">{{cite book |author=Ebert, D.A. |title=Sharks, Rays, and Chimaeras of California |publisher=University of California Press |location=London |year=2003 |isbn=0-520-23484-7 |pages=120–121}}</ref>

The [[sister species]] relationship between the longfin and shortfin makos has been confirmed by several [[phylogenetic]] studies based on [[mitochondrial DNA]]. In turn, the closest relative of the two mako sharks is the [[great white shark]] (''Carcharodon carcharias'').<ref>{{cite journal |author=Dosay-Abkulut, M. |url=http://journals.tubitak.gov.tr/biology/issues/biy-07-31-2/biy-31-2-8-0606-5.pdf|title=What is the Relationship within the Family Lamnidae? |journal=Turkish Journal of Biology |volume=31 |year=2007 |pages=109–113}}</ref> Fossil teeth belonging to the longfin mako have been recovered from the Muddy Creek marl of the Grange Burn formation, south of [[Hamilton, Victoria|Hamilton]], Australia, and from Mizumani Group in [[Gifu Prefecture]], Japan. Both deposits date to the [[Middle Miocene]] [[geological epoch|epoch]] (15–11 million years ago (Mya).<ref name="fitzgerald">{{cite journal |author=Fitzgerald, E. |title= A review of the Tertiary fossil Cetacea (Mammalia) localities in Australia |journal=Memoirs of Museum Victoria |volume=61 |issue=2 |pages=183–208 |year=2004 |url=http://museumvictoria.com.au/pages/3948/61_2_Fitzgerald.pdf}}</ref><ref>{{cite journal |doi=10.1111/j.1440-1738.1994.tb00115.x |author1=Yabumoto, Y. |author2=Uyeno, T. |lastauthoramp=yes |title=Late Mesozoic and Cenozoic fish faunas of Japan|url=https://www.fichier-pdf.fr/2013/02/15/yabumoto-y-uyeno-t-1994-meso-cenozoeque-japon/ |journal=The Island Arc |year=1994 |volume=3 |pages=255–269}}</ref>

==Distribution and habitat==

Widely scattered records suggest that the longfin mako shark has a worldwide distribution in tropical and warm-temperate oceans; the extent of its range is difficult to determine due to confusion with the shortfin mako. In the [[Atlantic Ocean]], it is known from the [[Gulf Stream]] off the [[east coast of the United States]], [[Cuba]], and southern [[Brazil]] in the west, and from the [[Iberian Peninsula]] to [[Ghana]] in the east, possibly including the [[Mediterranean Sea]] and [[Cape Verde]]. In the [[Indian Ocean]], it has been reported from the [[Mozambique Channel]]. In the [[Pacific Ocean]], it occurs off [[Japan]] and [[Taiwan]], northeastern Australia, a number of islands in the Central Pacific northeast of [[Micronesia]], and southern [[California]].<ref name="compagno"/>

An inhabitant of the open ocean, the longfin mako generally remains in the upper [[mesopelagic zone]] during the day and ascends into the [[epipelagic zone]] at night. Off Cuba, it is most frequently caught at a depth of {{convert|110|-|220|m|ft|abbr=on}} and is rare at depths above {{convert|90|m|ft|abbr=on}}. Off [[New South Wales]], most catches occur at a depth of {{convert|50|-|190|m|ft|abbr=on}}, in areas with a surface temperature around {{convert|20|-|24|C|F}}.<ref name="martin"/>

==Description==

The longfin mako is the larger of the two makos and the second-largest species in its family (after the great white), reaching upwards of {{convert|2.5|m|ft|abbr=on}} in length and weighing over {{convert|70|kg|lb|abbr=on}}; females grow larger than males.<ref name="wilson and ford">Wilson, T. and Ford, T. [http://www.flmnh.ufl.edu/fish/Gallery/Descript/longfinmako/longfinmako.html Biological Profiles: Longfin Mako]. Florida Museum of Natural History Ichthyology Department. Retrieved on December 25, 2008.</ref> The largest reported longfin mako was a 4.3-m-long female caught off [[Pompano Beach]], Florida, in February 1984.<ref name="martin">Martin, R.A. [http://www.elasmo-research.org/education/shark_profiles/i_paucus.htm Biology of the Longfin Mako (''Isurus paucus'')]. ReefQuest Centre for Shark Research. Retrieved on December 25, 2008.</ref> This species has a slim, [[wiktionary:fusiform|fusiform]] shape with a long, pointed snout and large eyes that lack [[nictating membrane]]s (protective third eyelids). Twelve to 13 tooth rows occur on either side of the upper jaw and 11–13 tooth rows are on either side of the lower jaw. The teeth are large and knife-shaped, without serrations or secondary cusps; the outermost teeth in the lower jaw protrude prominently from the mouth. The [[gill slit]]s are long and extend onto the top of head.<ref name="compagno"/><ref name="wilson and ford"/>

The pectoral fins are as long or longer than the head, with a nearly straight front margin and broad tips. The first [[dorsal fin]] is large with a rounded apex, and is placed behind the pectoral fins. The second dorsal and [[anal fin]]s are tiny. The [[caudal peduncle]] is expanded laterally into strong keels. The [[caudal fin]] is crescent-shaped, with a small notch near the tip of the upper lobe. The [[dermal denticle]]s are elliptical, longer than wide, with three to seven horizontal ridges leading to a toothed posterior margin. The coloration is dark blue to grayish black above and white below. The unpaired fins are dark except for a white rear margin on the anal fin; the pectoral and pelvic fins are dark above and white below with sharp gray posterior margins. In adults and large juveniles, the area beneath the snout, around the jaw, and the origin of the pectoral fins have dusky mottling.<ref name="compagno"/><ref name="wilson and ford"/>

<gallery mode=packed>

Isurus paucus ventral.jpg|The most distinctive features of the longfin mako shark are its large pectoral fins

Isurus paucus jaws.jpg|Jaws

Isurus paucus lower teeth.jpg|Lower teeth

Isurus paucus upper central teeth.jpg|Upper central teeth

Isurus paucus upper teeth.jpg|Upper teeth

</gallery>

==Biology and ecology==

The biology of the longfin mako is little-known; it is somewhat common in the western Atlantic and possibly the central Pacific, while in the eastern Atlantic, it is rare and outnumbered over 1000-fold by the shortfin mako in fishery landings.<ref name="iucn"/><ref name="compagno"/> The longfin mako's slender body and long, broad pectoral fins evoke the [[oceanic whitetip shark]] (''Carcharhinus longimanus'') and the [[blue shark]] (''Prionace glauca''), both slow-cruising sharks of upper oceanic waters. This [[morphology (biology)|morphological]] similarity suggests that the longfin mako is less active than the shortfin mako, one of the fastest and most energetic sharks.<ref name="compagno"/> Like the other members of its family, this species possesses [[blood vessel]] [[countercurrent exchange]] systems called the [[rete mirabilia]] (Latin for "wonderful net", singular rete mirabile) in its trunk musculature and around its eyes and brain. This system enables other mackerel sharks to conserve [[metabolism|metabolic heat]] and maintain a higher body temperature than their environments, though whether the longfin mako is capable of the same is uncertain.<ref name="compagno"/>

The longfin mako has large eyes and is attracted to cyalume sticks (chemical lights), implying that it is a visual hunter. Its diet consists mainly of small, schooling bony fishes and squids. In October 1972, a 3.4-m-long female with the broken bill from a [[swordfish]] (''Xiphius gladias'') lodged in her abdomen was caught in the northeastern Indian Ocean; whether the shark was preying on swordfish as the shortfin mako does, or encountered the swordfish in some other aggressive context is not known.<ref name="compagno"/><ref name="martin"/> Adult longfin makos likely have no natural predators, while young individuals may fall prey to larger sharks.<ref name="wilson and ford"/>

As in other mackerel sharks, the longfin mako is aplacental viviparous and typically gives birth to two pups at a time (one inside each [[uterus]]), though a 3.3-m-long female pregnant with eight well-developed embryos was caught in the [[Mona Passage]] near [[Puerto Rico]] in January 1983.<ref name="martin"/> The developing embryos are oophagous; once they deplete their supply of [[yolk]], they sustain themselves by consuming large quantities of nonviable eggs [[ovulation|ovulated]] by their mother. No evidence of [[adelphophagy|sibling cannibalism]] is seen as in the [[sand tiger shark]] (''Carcharias taurus''). The pups measure {{convert|97|-|120|cm|ft|abbr=on}} long at birth, relatively larger than the young of the shortfin mako, and have proportionally longer heads and pectoral fins than the adults.<ref name="wilson and ford"/><ref name="gilmore">{{cite journal |title=Observations on the Embryos of the Longfin Mako, ''Isurus paucus'', and the Bigeye Thresher, ''Alopias superciliosus'' |author=Gilmore, R.G. |journal=Copeia |volume=1983 |issue=2 |date=May 6, 1983 |pages=375–382 |doi=10.2307/1444380 |publisher=American Society of Ichthyologists and Herpetologists |jstor=1444380}}</ref> Capture records off Florida suggest that during the winter, females swim into shallow coastal waters to give birth.<ref name="fishbase">{{fishbase species |genus=Isurus |species=paucus |month=December |year=2008}}</ref> Male and female sharks reach [[sexual maturity]] at lengths around {{convert|2|m|ft|abbr=on}} and {{convert|2.5|m|ft|abbr=on}}, respectively.<ref name="martin"/>

==Human interactions==

[[File:Isurus paucus 2.jpg|thumb|upright=1.2|The longfin mako is caught as bycatch on pelagic longlines.]]

No attacks on humans have been attributed to the longfin mako shark.<ref name="compagno"/> Nevertheless, its large size and teeth make it potentially dangerous.<ref name="ebert"/> This shark is caught, generally in low numbers, as [[bycatch]] on [[longline fishing|longline]]s intended for tuna, swordfish, and other pelagic sharks, as well as in anchored [[gillnet]]s and on hook-and-line. The meat is marketed fresh, frozen, or dried and salted, though it is considered to be of poor quality due to its mushy texture. The fins are also considered to be of lower quality for use in [[shark fin soup]], though are valuable enough that captured sharks are often [[shark finning|finned]] at sea.<ref name="iucn"/> The carcasses may be processed into [[compound feed|animal feed]] and [[fishmeal]], while the skin, cartilage, and jaws are also of value.<ref name="wilson and ford"/><ref name="fishbase"/>

The most significant longfin mako catches are by Japanese tropical longline fisheries, and those sharks occasionally enter [[Tokyo]] markets. From 1987 to 1994, United States fisheries reported catches (discarded, as this species is worthless on the North American market) of 2–12 tons per year.<ref name="iucn"/> Since 1999, retention of this species has been prohibited by the U.S. [[National Marine Fisheries Service]] Fishery Management Plan for Atlantic sharks.<ref name="fowler et al">{{cite book |author=Fowler, S.L. |author2=Cavanagh, R.D. |author3=Camhi, M. |author4=Burgess, G.H. |author5=Cailliet, G.M. |author6=Fordham, S.V. |author7=Simpfendorfer, C.A. |author8=Musick, J.A. |last-author-amp=yes |title=Sharks, Rays and Chimaeras: The Status of the Chondrichthyan Fishes |publisher=International Union for Conservation of Nature and Natural Resources |year=2005 |isbn=2-8317-0700-5 |pages=106–109}}</ref> Longfin makos were once significant in the Cuban longline fishery, comprising a sixth of the shark landings from 1971 to 1972; more recent data from this fishery are not available. The IUCN has assessed this species as vulnerable due to its uncommonness, low reproductive rate, and susceptibility to shark fishing gear. It has also been listed under Annex I of the [[Bonn Convention|Convention on Migratory Species]] [[Memorandum of Understanding - Migratory Sharks|Migratory Shark Memorandum of Understanding]].<ref>[http://www.cms.int/species/sharks/MoU/Migratory_Shark_MoU_Eng.pdf Memorandum of Understanding – Migratory Sharks]. Convention on Migratory Species. Downloaded on February 14, 2012.</ref> In the North Atlantic, stocks of the shortfin mako have declined 40% or more since the late 1980s, and concerns exist that populations of the longfin mako are following the same trend.<ref name="iucn"/>

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==See an aw==

*[[:en:List of common commercial fish of Sri Lanka#Mackerel Sharks|List of common commercial fish of Sri Lanka]]

==References==

{{reflist|colwidth=30em}}

==Freemit airtins==

{{Commons category|Isurus paucus|Longfin mako shark}}

* [http://www.fishbase.org/Summary/SpeciesSummary.cfm?genusname=Isurus&speciesname=paucus ''Isurus paucus'', Longfin mako] at [http://www.fishbase.org/search.php FishBase]

* {{IUCNlink|60225|Isurus paucus'' (Longfin Mako)}} at [http://www.iucnredlist.org/ IUCN Red List]

* [http://www.flmnh.ufl.edu/fish/Gallery/Descript/longfinmako/longfinmako.html Biological Profiles: Longfin Mako] at [http://www.flmnh.ufl.edu/fish/ Florida Museum of Natural History Ichthyology Department]

* [http://www.elasmo-research.org/education/shark_profiles/i_paucus.htm Biology of the Longfin Mako] at [http://elasmo-research.org/index.html ReefQuest Centre for Shark Research]

{{Lamniformes}}

{{good article}}

[[Category:Lamnidae]]

[[Category:Ainimals described in 1966]]

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