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{{Short description|Species of shark}}
{{Good article}}
{{Speciesbox
| name = Smooth hammerhead
| status = VU
| status_system = IUCN3.1
| status_ref = <ref name="iucn status 19 November 2021">{{cite iucn |author=Rigby, C.L. |author2=Barreto, R. |author3=Carlson, J. |author4=Fernando, D. |author5=Fordham, S. |author6=Herman, K. |author7=Jabado, R.W. |author8=Liu, K.M. |author9=Marshall, A. |author10=Pacoureau, N. |author11=Romanov, E. |author12=Sherley, R.B. |author13=Winker, H. |date=2019 |title=''Sphyrna zygaena'' |volume=2019 |page=e.T39388A2921825 |doi=10.2305/IUCN.UK.2019-3.RLTS.T39388A2921825.en |access-date=19 November 2021}}</ref>
| status2 = CITES_A2 
| status2_system = CITES 
| status2_ref = <ref>{{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}</ref>
| image = Sphyrna zygaena noaa.jpg
| genus = Sphyrna
| species = zygaena
| authority = ([[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]])
| range_map = Sphyrna zygaena distribution map.svg
| range_map_caption = Range of the smooth hammerhead
| synonyms = *''Squalis pictus''* <small>Blainville, 1816</small>
*''Squalus carolinensis''* <small>Blainville, 1816</small>
*''Squalus zygaena'' <small>[[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]</small>
*''Zygaena malleus'' <small>Valenciennes, 1822</small>
*''Zygaena subarcuata'' <small>Storer, 1848</small>
*''Zygaena vulgaris '' <small>Cloquet, 1830</small>
----
<small>* ambiguous synonym</small>
}}

The '''smooth hammerhead''' ('''''Sphyrna zygaena''''') is a [[species]] of [[hammerhead shark]], and part of the family Sphyrnidae. This species is named "smooth hammerhead" because of the distinctive shape of the head, which is flattened and laterally extended into a [[hammer]] shape (called the "cephalofoil"), without an indentation in the middle of the front margin (hence "smooth"). Unlike other hammerheads, this species prefers [[temperate]] waters and occurs worldwide at medium [[latitude]]s. In the summer, these sharks [[fish migration|migrate]] towards the poles following cool water masses, sometimes forming [[shoaling and schooling|schools]] numbering in the hundreds to thousands.

The second-largest hammerhead shark after the [[great hammerhead shark]], the smooth hammerhead can measure up to {{convert|5|m|ft|abbr=on}} long. It is an active [[predator]] that takes a wide variety of [[bony fish]]es and [[invertebrate]]s, with larger individuals also feeding on [[elasmobranch|sharks and rays]]. As in the rest of its family, this shark is [[viviparous]] and gives birth to litters of 20&ndash;40 pups. A relatively common shark, it is captured, intentionally or otherwise, by many [[commercial fishing|commercial fisheries]] throughout its range; its fins are extremely valuable for use in [[shark fin soup]]. This shark is potentially dangerous and has likely been responsible for a few [[shark attack|attacks on humans]], though it is less likely to encounter swimmers than other large hammerhead species due to its temperate [[habitat]].

==Taxonomy and phylogeny==
The Swedish natural historian [[Carl Linnaeus]], known as the "father of [[Taxonomy (biology)|taxonomy]]", originally described the smooth hammerhead as ''Squalus zygaena'' in the 1758 [[10th edition of Systema Naturae|tenth edition]] of ''[[Systema Naturae]]'', without designating a [[type specimen]]. The name was later changed to ''Sphyrna zygaena''.<ref name="compagno"/> The [[specific name (zoology)|specific epithet]] ''zygaena'' originates from the [[Greek language|Greek]] word ''zygòn'', meaning "[[yoke]]", referring to the shape of its head.<ref name="ellis">{{cite book |author=Ellis, R. |title=The Book of Sharks |publisher=Alfred A. Knopf Inc. |location=New York |year=1989 |isbn=0-679-72210-6 |url-access=registration |url=https://archive.org/details/bookofsharks00elli }}</ref> The Greek name ''zýgaina'' had already been used for the hammerhead shark by [[Aristotle]] in the second book of his ''[[History of Animals]]''.<ref>Aristotle (350 BCE). [http://remacle.org/bloodwolf/philosophes/Aristote/animaux2.htm#XI "Ch. XI.11"]. ''History of Animals'' (Book II)</ref> Other common names for this species include common hammerhead, common smooth hammerhead, round-headed hammerhead, or simply hammerhead.<ref name="fishbase">{{FishBase |genus=Sphyrna |species=zygaena |year=2008 |month=January}}</ref>

{{cladogram|title=|align=left|caption=Phylogenetic tree of hammerhead sharks.<ref name="lim et al"/>
|clades={{clade|style=font-size:80%;line-height:80%
|1={{clade
 |1=''[[Eusphyra blochii]]''
 |2={{clade
  |1={{clade
   |1=''[[Sphyrna mokarran]]'' <span style="{{MirrorH}}">[[File:Great hammerhead (Duane Raver).png|50 px]]</span>
   |2='''''Sphyrna zygaena''''' <span style="{{MirrorH}}">[[File:Smooth hammerhead (Duane Raver).png|50 px]]</span>
  }}
  |2={{clade
   |1=''[[Sphyrna lewini]]'' <span style="{{MirrorH}}">[[File:Scalloped hammerhead (Duane Raver).png|50 px]]</span>
   |2={{clade
    |1={{clade
     |1=''[[Sphyrna tudes]]''
     |2=''[[Sphyrna media]]''
    }}
    |2={{clade
     |1=''[[Sphyrna tiburo]]'' <span style="{{MirrorH}}">[[File:Bonnethead shark (Duane Raver).png|50 px]]</span>
     |2=''[[Sphyrna corona]]''
    }}
  }}
  }}
 }}
}}
}}
}}
Studies based on [[morphology (biology)|morphology]] have generally regarded the smooth hammerhead as one of the more [[derived (phylogenetics)|derived]] members of its family, grouped together with the [[scalloped hammerhead]] (''S. lewini'') and the [[great hammerhead]] (''S. mokarran''). [[Phylogenetic]] analyses based on [[nuclear DNA|nuclear]] and [[mitochondrial DNA]] have concluded differently: while the smooth and great hammerheads are closely related, they are not as closely related to the scalloped hammerhead as the other ''Sphyrna'' species. Furthermore, the smooth hammerhead is among the more [[Basal (phylogenetics)|basal]] hammerhead species, indicating that the first hammerheads to evolve had large cephalofoils.<ref name="lim et al">{{cite journal |author1=Lim, D.D. |author2=Motta, P. |author3=Mara, K. |author4=Martin, A.P. |year=2010 |title=Phylogeny of hammerhead sharks (Family Sphyrnidae) inferred from mitochondrial and nuclear genes |journal=Molecular Phylogenetics and Evolution |volume=55 |issue=2 |pages=572–579 |doi=10.1016/j.ympev.2010.01.037 |pmid=20138218|bibcode=2010MolPE..55..572L }}</ref><ref name="cavalcanti">{{cite journal |author=Cavalcanti, M.J. |title=A Phylogenetic Supertree of the Hammerhead Sharks (Carcharhiniformes: Sphyrnidae) |journal=Zoological Studies |volume=46 |issue=1 |pages=6&ndash;11 |year=2007}}</ref>

==Description==
[[File:Sphyrna corona-zygaena compare.jpg|thumb|left|The [[scalloped hammerhead]] (left) and the smooth hammerhead (right) differ in cephalofoil shape.]]
[[File:Sphyrna zygaena upper teeth.jpg|thumb|Upper teeth]]
[[File:Sphyrna zygaena lower teeth.jpg|thumb|Lower teeth]]
The second-largest hammerhead next to the great hammerhead, the smooth hammerhead typically measures {{convert|2.5|-|3.5|m|ft|abbr=on}} long, with a maximum recorded length and weight of {{convert|5|m|ft|abbr=on}} and {{convert|400|kg|lb|abbr=on}} respectively.<ref name="bester"/> The smooth hammerhead differs from other large hammerheads in the shape of its cephalofoil, which has a curved front margin without an indentation in the center. The cephalofoil is wide but short, measuring 26&ndash;29% of the body length across. The [[nostril]]s are located near the ends of the cephalofoil, with long grooves running towards the center. There are 26&ndash;32 tooth rows in the upper jaw and 25&ndash;30 tooth rows in the lower jaw. Each tooth is triangular in shape, with smooth to weakly serrated edges.<ref name="bester"/>

The body is streamlined, without a dorsal ridge between the two [[dorsal fin]]s. The first dorsal fin is moderately tall and falcate (sickle-like) in shape, with a rounded tip. The [[pectoral fin|pectoral]] and [[pelvic fin]]s are not falcate, rather having nearly straight rear margins. The [[anal fin]] is larger than the second dorsal fin, with long free rear tip and a strong notch in the rear margin.<ref name="compagno"/> The [[dermal denticle]]s are densely packed, each with 5&ndash;7 horizontal ridges (3 in juveniles) leading to a W-shaped rear margin. The back is dark brownish gray to olive in color, in contrast to the simple brown of most other hammerheads, becoming lighter on the flanks. The belly is white, and sometimes the pectoral fins have dark edges underneath.<ref name="bester">Bester, C. [http://www.flmnh.ufl.edu/fish/Gallery/Descript/SmHammer/SmoothHammerhead.html Biological Profiles: Smooth Hammerhead]. Florida Museum of Natural History Ichthyology Department. Retrieved on October 19, 2008.</ref>

==Distribution and habitat==
Of the hammerhead sharks, the smooth hammerhead is the species most tolerant of temperate water, and occurs worldwide to higher [[latitude]]s than any other species. In the [[Atlantic]], it occurs from [[Nova Scotia]] to the [[Virgin Islands]] and from [[Brazil]] to southern [[Argentina]] in the west, and from the [[British Isles]] to [[Côte d'Ivoire]], including the [[Mediterranean Sea]], in the east.<ref name="compagno">{{cite book |author=Compagno, L.J.V. |year=1984 |title=Sharks of the World: An Annotated and Illustrated Catalogue of Shark Species Known to Date |place=Rome |publisher=Food and Agricultural Organization |isbn=92-5-101384-5 |pages=553&ndash;554}}</ref> In Northern Europe, there are only seven confirmed records from the British Isles, all but one (at [[Banffshire]]) from the southern part of the archipelago and all but two (in 2004 and 2019) from more than 100 years ago.<ref>{{cite journal |author=Southall, E.J. |author2=D.W. Sims | date=2005 | title=A smooth hammerhead shark (Sphyrna zygaena) from south-west England | journal=Marine Biodiversity Records | volume=1 | pages=e9 | doi=10.1017/S1755267206000984 }}</ref><ref>{{cite news | author=Kelly, B | title=Hammerhead shark spotted in Irish waters for the first time ever | url=https://galwaydaily.com/news/hammerhead-shark-spotted-in-irish-water/ | date=21 July 2019 | publisher=Galway Daily | access-date=10 December 2019 }}</ref> The oft-repeated claim of a 1937 capture from the [[Kattegat]] (Denmark) is incorrect, as a photo from the incident has revealed that it was a [[basking shark]],<ref>{{cite news | title=Myte om dansk hammerhaj grundigt punkteret | url=http://illvid.dk/dyr/havdyr/hajer/myte-om-dansk-hammerhaj-grundigt-punkteret | date=9 February 2015 | publisher=[[Illustreret Videnskab]] | access-date=4 November 2017 }}</ref> although there was a confirmed observation of a hammerhead in the [[North Sea]] off [[Jutland]] in 2003, which most likely was a smooth hammerhead.<ref>{{cite journal | author1=Carl, H. | author2=J.G. Nielsen | author3=P.R. Møller | year=2005 | title=En kommenteret og revideret oversigt over danske fisk | journal=Flora og Fauna | volume=110 | issue=2 | pages=29–39 }}</ref> In the [[Indian Ocean]], it is found off [[South Africa]], [[India]], and [[Sri Lanka]]. In the western [[Pacific]], it occurs from the [[Gulf of Tonkin]] to southern [[Japan]] and the [[Russian Far East]], as well as off [[Australia]] and [[New Zealand]]. In the central and eastern Pacific, it occurs off the [[Hawaiian Islands]], [[California]], [[Panama]], the [[Galapagos Islands]], [[Ecuador]], and [[Chile]], with a report in 1954 of two unidentified hammerheads off [[British Columbia]] which probably were smooth hammerheads. This species is usually considered to be amphitemperate (absent from the [[tropics]]) in distribution, though there are rare reports from tropical waters such as in the [[Gulf of Mannar]] off India, and off southern [[Mozambique]]. Its presence in the tropics is difficult to determine due to confusion with other hammerhead species.<ref name="compagno"/> Although generally preferring subtropical and warm temperate regions, a study of captures in the West Atlantic and [[Gulf of Mexico]] off the United States recorded smooth hammerheads in water temperatures ranging from  {{convert|7.5|to(-)|27.5|C|F|abbr=on}}.<ref>{{cite journal |author=Grace, M. |author2=T. Henwood | date=1997 | title=Assessment of the Distribution and Abundance of Coastal Sharks in the U.S. Gulf of Mexico and Eastern Seaboard, 1995 and 1996 | journal=Marine Fisheries Review | volume=59 | issue=4 | pages=23–32 }}</ref>

Compared to the scalloped and great hammerheads, the smooth hammerhead stays closer to the surface, in water less than {{convert|20|m|ft|abbr=on}} deep. However, it has been recorded diving to a depth of {{convert|200|m|ft|abbr=on}}. It prefers inshore waters such as [[bay]]s and [[estuaries]], but is sometimes found in the open ocean over the [[continental shelf]], and around oceanic islands. This shark has also been reported entering [[freshwater]] habitats, such as the [[Indian River (Florida)|Indian River]] in [[Florida]]. In the summer, smooth hammerheads migrate poleward to stay in cooler water, heading back towards the [[equator]] in winter.<ref name="ebert">{{cite book |author=Ebert, D.A. |title=Sharks, Rays, and Chimaeras of California |publisher=University of California Press |year=2003 |isbn=0-520-23484-7 |pages=178&ndash;179}}</ref>

==Biology and ecology==
[[File:hammerhead.jpg|thumb|A migrating smooth hammerhead swimming with its dorsal fin exposed]]
Adult smooth hammerheads are either solitary or form small groups. They may come together in great numbers during their annual migrations; schools of over a hundred juveniles under {{convert|1.5|m|ft|abbr=on}} long have been observed off the eastern Cape of [[South Africa]], and schools thousands strong have been reported off California.<ref name="compagno"/><ref name="ebert"/> During hot summer weather, they can be seen swimming just below the surface with their dorsal fins exposed.<ref name="bester"/> Young smooth hammerheads are preyed upon by larger sharks such as the [[dusky shark]] (''Carcharhinus obscurus'');<ref name="bester"/> adults have been observed being consumed by [[killer whale]]s (''Orcinus orca'') off New Zealand.<ref>{{cite journal |author=Visser, I.N. |author-link= Ingrid Visser (researcher) |title=First Observations of Feeding on Thresher (''Alopias vulpinus'') and Hammerhead (''Sphyrna zygaena'') Sharks by Killer Whales (''Orcinus orca'') Specialising on Elasmobranch Prey |journal=Aquatic Mammals |volume=31 |issue=1 |date=January 2005 |pages=83&ndash;88 |doi=10.1578/AM.31.1.2005.83}}</ref> Known [[parasite]]s of the smooth hammerhead include the [[nematode]]s ''Parascarophis sphyrnae'' and ''Contracaecum'' spp.<ref name="bester"/>

The smooth hammerhead is an active-swimming predator that feeds on bony fishes, rays, sharks (including of its own species), cephalopods, and to a lesser extent [[crustacean]]s such as [[shrimp]], [[crab]]s, and [[barnacle]]s. They readily [[scavenger|scavenge]] from fishing lines.<ref name="compagno"/> In some areas, [[stingray]]s are a favored prey and comprise a majority of its diet. The [[venom]]ous barbs of stingrays are often found lodged in and around the mouths of these sharks; one specimen examined contained 95 such spines.<ref name="strong et al.">{{cite journal |author=Strong, W.R. |author2=Snelson Jr., F.F. |author3=Gruber, S.H. |name-list-style=amp |title=Hammerhead Shark Predation on Stingrays: An Observation of Prey Handling by ''Sphyrna mokarran'' |journal=Copeia |volume=1990 |issue=3 |pages=836&ndash;840 |date=September 19, 1990 |doi=10.2307/1446449 |jstor=1446449 |publisher=American Society of Ichthyologists and Herpetologists}}</ref> In northern [[Europe]], the smooth hammerhead feeds on [[herring]] and [[European seabass|seabass]], while in [[North America]] it takes [[Atlantic Spanish mackerel|Spanish mackerel]] and [[menhaden]].<ref name="bester"/> Off South Africa, smooth hammerheads feed on squid such as ''[[Loligo vulgaris]]'' and small schooling fish such as [[pilchard]] over the deep [[coral reef]]s at the edge of the continental shelf, with individuals over {{convert|2|m|ft|abbr=on}} long taking increasing numbers of smaller [[elasmobranch|sharks and ray]]s. Off Australia, squid are the most important prey, followed by bony fish.<ref name="fowler et al"/><ref name="smale">{{cite journal |author=Smale, M.J. |title=Occurrence and feeding of three shark species, ''Carcharhinus brachyurus'', ''C. obscurus'' and ''Sphyrna zygaena'', on the Eastern Cape coast of South Africa |journal=South African Journal of Marine Science |volume=11 |issue=1 |date=December 1991 |pages=31&ndash;42 |doi=10.2989/025776191784287808|doi-access= }}</ref> Though definitely rare, there are observations of smooth hammerheads attempting to predate on [[dolphins]].<ref>{{cite journal |last1=Sucunza |first1=Federico |last2=Doria |first2=Eliza |last3=Alves |first3=Luiz C. P. de S. |last4=Prado |first4=Jonatas Fernandes |title=Observations of antipredator tactics among pantropical spotted dolphins (Stenella attenuata) attacked by smooth hammerhead sharks (Sphyrna zygaena) |journal=Marine Mammal Science |date=April 2015 |volume=31 |issue=2 |page=748 |doi=10.1111/mms.12169|bibcode=2015MMamS..31..748S }}</ref>

Like other hammerheads, the smooth hammerhead is viviparous: once the young exhaust their supply of [[yolk]], the empty [[yolk sac]] is converted into a [[placenta]]l connection through which the mother delivers nourishment. Females bear relatively large litters of 20&ndash;50 pups after a [[gestation period]] of 10&ndash;11 months.<ref name="ebert"/> Birthing occurs in shallow coastal nurseries, such as Bulls Bay in [[North Carolina]].<ref>{{cite book |page=197 |author1=Sumich, J.L.  |author2=Morrissey, J.F.  |name-list-style=amp |title=Introduction to the Biology of Marine Life |publisher=Jones & Bartlett Publishers |edition=eighth |year=2004 |isbn=0-7637-3313-X}}</ref> The pups measure {{convert|50|-|61|cm|in|abbr=on}} long at birth; females reach maturity at {{convert|2.7|m|ft|abbr=on}} long and males at {{convert|2.1|-|2.5|m|ft|abbr=on}} long, depending upon locality.<ref name="bester"/> Off South Africa, newly mated females have been caught in February and females with full-term embryos in November; off the east coast of Australia, birthing takes place between January and March, with [[ovulation]] taking place around the same time.<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. |name-list-style=amp |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&ndash;109, 318&ndash;320}}</ref> This shark is thought to live for 20 years or more.<ref name="bester"/>

==Human interactions==
[[File:Sphyrna zygaena in a tank.jpg|thumb|A smooth hammerhead in [[Aqua World]], [[Japan]]]]
The smooth hammerhead is potentially dangerous to humans. As of 2008, the [[International Shark Attack File]] lists 34 attacks attributable to large hammerhead sharks, 17 of them unprovoked (none fatal).<ref>[http://www.flmnh.ufl.edu/fish/sharks/statistics/species2.htm ISAF Statistics on Attacking Species of Shark]. International Shark Attack File, Florida Museum of Natural History, University of Florida. Retrieved on May 18, 2009.</ref> However, due to the smooth hammerhead's occurrence in temperate regions where people are less likely to enter the water, it was likely responsible for a minority of these attacks.<ref name="bester"/> Off southern California, this species has been reported to steal catches from sport fishers and divers.<ref name="compagno"/>

Smooth hammerheads are caught by commercial fisheries throughout the world, including those off the [[United States]] (East and West Coasts), [[Brazil]], [[Spain]], [[Taiwan]], the [[Philippines]], southwestern Australia, and western [[Africa]], primarily using [[gillnet]]s and [[longline fishing|longlines]]. Fishery catches of smooth hammerheads are difficult to quantify due to a frequent lack of distinction between them and other large hammerheads.<ref name="fowler et al"/> The meat is sold fresh, dried and salted, or smoked, though in most markets it is considered undesirable and there are reports of [[poison]]ing. Much more valuable are the fins, which have the highest rating for use in [[shark fin soup]] and often leads to captured sharks being [[shark finning|finned]] at sea. Additionally, the [[shark liver oil|liver oil]] is used for [[vitamin]]s, the skin for [[leather]], and the [[offal]] for [[fishmeal]].<ref name="bester"/> This shark is also used in [[Chinese medicine]].<ref name="fishbase"/>

Many other fisheries from every ocean also take smooth hammerheads as [[bycatch]], and they are caught in some numbers by [[recreational fishing|recreational angler]]s. Smooth hammerheads are also killed by entanglement in [[shark net]]s used to protect beaches. Fewer than 10 smooth hammerheads were caught annually in the nets off [[KwaZulu-Natal]], South Africa, from 1978&ndash;1990. In contrast, in the nets off [[New South Wales]], Australia, smooth hammerheads comprised 50% of the 4,715 sharks captured from 1972&ndash;1990.<ref name="fowler et al"/> At present, this species remains relatively common and has been assessed as "[[Vulnerable species|Vulnerable (VU)]]" by the World Conservation Union.<ref name="iucn status 19 November 2021" /> Off New Zealand, it is a prohibited target species and is the most abundant shark along the northwest coast. In June 2018 the New Zealand [[Department of Conservation (New Zealand)|Department of Conservation]] classified the smooth hammerhead as "Not Threatened" with the qualifier "Secure Overseas" under the [[New Zealand Threat Classification System]].<ref>{{Cite book|url=https://www.doc.govt.nz/globalassets/documents/science-and-technical/nztcs23entire.pdf|title=Conservation status of New Zealand chondrichthyans (chimaeras, sharks and rays), 2016|last1=Duffy|first1=Clinton A. J.|last2=Francis|first2=Malcolm|last3=Dunn|first3=M. R.|last4=Finucci|first4=Brit|last5=Ford|first5=Richard|last6=Hitchmough|first6=Rod|last7=Rolfe|first7=Jeremy|publisher=Department of Conservation|year=2018|isbn=9781988514628|location=Wellington, New Zealand|pages=11|oclc=1042901090}}</ref>

It also does not appear to have been negatively impacted by fishing off southern Australia.<ref name="bester" /> Off the eastern United States, catches of this species are regulated by the [[National Marine Fisheries Service]] (NMFS) Atlantic shark Fishery Management Plan (FMP), under which it is classified as a Large Coastal Shark (LCS).<ref name="fowler et al" /> In 2013, the smooth hammerhead and other great [[elasmobranchs]] were added to Appendix 2 of [[CITES]], meaning international trade (including in parts and derivatives) is regulated by the CITES permitting system.<ref>{{cite web| url=http://www.cites.org/eng/news/pr/2013/20130314_cop16.php| title=CITES conference takes decisive action to halt decline of tropical timber, sharks, manta rays and a wide range of other plants and animals| website=Cites| date=14 March 2013}}</ref>

==References==
{{Reflist|colwidth=30em}}

==External links==
{{Commons category|Sphyrna zygaena}}
* [http://shark-references.com/species/view/Sphyrna-zygaena ''Sphyrna zygaena'' at Shark-references.com]

{{Carcharhiniformes}}
{{Taxonbar|from=Q726259}}
{{Authority control}}

[[Category:Sphyrna|smooth hammerhead]]
[[Category:Cosmopolitan fish]]
[[Category:Vulnerable fish]]
[[Category:Vulnerable biota of Africa]]
[[Category:Vulnerable fauna of Asia]]
[[Category:Vulnerable biota of Europe]]
[[Category:Vulnerable fauna of Oceania]]
[[Category:Vulnerable biota of South America]]
[[Category:Marine fish of Europe]]
[[Category:Marine fish of Asia]]
[[Category:Marine fish of Africa]]
[[Category:Fish of North America]]
[[Category:Fish of the Caribbean]]
[[Category:Fish of the Dominican Republic]]
[[Category:Fish of South America]]
[[Category:Fish described in 1758|smooth hammerhead]]
[[Category:Taxa named by Carl Linnaeus|smooth hammerhead]]