Editing Paddlefish (section)

{{Short description|Family of fishes related to sturgeons}}
{{Distinguish|Oarfish}}
{{Good article}}{{use dmy dates|date=December 2024}}
{{Automatic taxobox
| name = Paddlefishes
| image = Paddlefish Polyodon spathula.jpg
| image_caption = [[American paddlefish]], ''Polyodon spathula''
| image2 = A_specimen_of_Psephurus_gladius,_Museum_of_Hydrobiological_Sciences,_Wuhan_Institute_of_Hydrobiology_(4).jpg
| image2_caption = [[Chinese paddlefish]], {{extinct}} ''Psephurus gladius''
| fossil_range = {{Fossil range|Barremian|Recent}}<ref name=FB>{{FishBase_family |family=Polyodontidae |year=2009 |month=January}}</ref>
| taxon = Polyodontidae
| authority = [[Charles Lucien Bonaparte|Bonaparte]], 1838
| subdivision_ranks = Genera
| subdivision =
Recent genera
* ''[[American paddlefish|Polyodon]]''
* {{Extinct}}''[[Chinese paddlefish|Psephurus]]''
Fossil genera
* {{Extinct}}''[[Crossopholis]]''
* {{Extinct}}''[[Paleopsephurus]]'' 
* {{Extinct}}''[[Parapsephurus]]''<ref name=Hilton2023/>
* {{Extinct}}''[[Protopsephurus]]''
* {{Extinct}}''[[Pugiopsephurus]]''<ref name=Hilton2023/>
}}

'''Paddlefish''' (family '''Polyodontidae''') are a family of [[ray-finned fish]] belonging to order [[Acipenseriformes]], and one of two living groups of the order alongside [[sturgeon]]s (Acipenseridae).<ref name=Crow2012>{{cite journal |last1 = Crow |first1 = K.D. |last2 = Smith | first2 = C.D. |last3 = Cheng |first3 = J.-F. |last4 = Wagner |first4 = G.P. |last5 = Amemiya |first5 = C.T. |year = 2012 |title = An independent genome duplication inferred from hox paralogs in the American Paddlefish – a representative basal ray-finned fish and important comparative reference |journal = Genome Biology and Evolution |volume = 4 |issue = 9 |pages = 937–953 |pmc = 3509897 |doi = 10.1093/gbe/evs067 |pmid = 22851613 }}</ref><ref name=TexasPWD-sp-dsc>{{cite web |title=Paddlefish (''Polyodon spathula'') |website=tpwd.texas.gov |url=https://tpwd.texas.gov/huntwild/wild/species/pad/ |access-date=2022-12-02 }}</ref> They are distinguished from other fish by their elongated [[Rostrum (anatomy)|rostra]], which are thought to enhance [[electroreception]] to detect prey. Paddlefish have been referred to as "[[primitive fish]]" because the Acipenseriformes are among the earliest diverging lineages of ray-finned fish, having diverged from all other living groups over 300&nbsp;million years ago. Both living and fossil paddlefish are found almost exclusively in North America and China.<ref name=Wilkens-Hofmann-2007>{{cite journal | last1=Wilkens | first1=Lon A. | last2=Hofmann | first2=Michael H. | year=2007 | title=The paddlefish rostrum as an electrosensory organ: A novel adaptation for plankton feeding | journal=BioScience | volume=57 | issue=5 | pages=399–407 | doi=10.1641/B570505 | doi-access=free }}</ref>

Eight species are known: Six of those species are extinct, and known only from fossils (five from North America, one from China),<ref name=Hilton2023>
<br/>{{cite journal
 |last1=Hilton |first1=E.J. |last2=During  |first2=M.A.D.
 |last3=Grande |first3=L.   |last4=Ahlberg |first4=P.E.
 |year=2023
 |title=New paddlefishes (Acipenseriformes, Polyodontidae) from the late Cretaceous Tanis site of the Hell Creek formation in North Dakota, USA
 |journal=Journal of Paleontology
 |volume=97 |issue=3 |pages=675–692
 |doi=10.1017/jpa.2023.19 |doi-access=free
 |s2cid=258095684
}}
</ref> one of the [[Extant taxon|extant]] species, the [[American paddlefish]] (''Polyodon spathula''), is native to the [[Mississippi River]] basin in the U.S. The other is the [[Chinese paddlefish]] (''Psephurus gladius''), which was declared extinct in 2022 following a 2019 recommendation;<ref name=Reuters2022>{{cite news |title=Chinese paddlefish and wild Yangtze sturgeon extinct - IUCN |agency=[[Reuters]] |date=2022-07-22 |df=dmy-all |lang=en |url=https://www.reuters.com/business/environment/chinese-paddlefish-wild-yangtze-sturgeon-extinct-iucn-2022-07-22/ |access-date=2022-07-22 |archive-date=23 July 2022 |archive-url=https://web.archive.org/web/20220723155510/https://www.reuters.com/business/environment/chinese-paddlefish-wild-yangtze-sturgeon-extinct-iucn-2022-07-22/ |url-status=live }}</ref><ref name=SD2019>{{cite journal | last1=Zhang | first1=Hui | last2=Jarić | first2=Ivan | last3=Roberts | first3=David L. | last4=He | first4=Yongfeng | last5=Du | first5=Hao | last6=Wu | first6=Jinming | last7=Wang | first7=Chengyou | last8=Wei | first8=Qiwei | display-authors=6 | year=2020 | title=Extinction of one of the world's largest freshwater fishes: Lessons for conserving the endangered Yangtze fauna | journal=Science of the Total Environment | volume=710 | pages=136242 | issn=0048-9697 | doi=10.1016/j.scitotenv.2019.136242 | pmid=31911255 | bibcode=2020ScTEn.71036242Z | s2cid=210086307 }}</ref><ref name=Oceanographic-2020>{{cite web | title=Study declares ancient Chinese paddlefish extinct | magazine=Oceanographic magazine | date=2020-01-09 | url=https://www.oceanographicmagazine.com/news/chinese-paddlefish-extinct/ | access-date=2022-04-23 | df=dmy-all }}</ref> the species has not been sighted in the [[Yangtze River Basin]] in China since 2003.<ref name=SCMPost-2020>{{cite web | title=Chinese paddlefish, native to the Yangtze River, declared extinct by scientists | newspaper=[[South China Morning Post]] | date=2020-01-04 | df=dmy-all | url=https://www.scmp.com/news/china/society/article/3044520/chinese-paddlefish-native-yangtze-river-declared-extinct | access-date=2020-01-04}}</ref><ref name=IUCN-Chinese>{{cite iucn |last=Qiwei |first=W. |year=2010 |title=''Psephurus gladius'' |volume=2010 |page=e.T18428A8264989 |doi=10.2305/IUCN.UK.2010-1.RLTS.T18428A8264989.en <!-- |access-date=11 November 2021 --- access date requires a URL --> }}</ref> Chinese paddlefish are also commonly referred to as "Chinese swordfish", or "elephant fish".<ref name=FAO>{{cite web | title=''Psephurus gladius'' (Martens, 1862) | department=Species Fact Sheet | publisher=[[Food and Agriculture Organization of the United Nations]] | series=Fisheries and Aquaculture Department | url=http://www.fao.org/fishery/species/14620/en | access-date=June 10, 2014 | url-status=live | archive-url=https://web.archive.org/web/20150707033220/http://www.fao.org/fishery/species/14620/en | archive-date=July 7, 2015 }}</ref> The earliest known paddlefish is ''[[Protopsephurus]]'', from the [[early Cretaceous]] ([[Aptian]]) of China, dating to around 120&nbsp;million years ago.

Paddlefish populations have declined dramatically throughout their historic range as a result of [[overfishing]], pollution, and the encroachment of human development, including the construction of dams that have blocked their seasonal upward migration to ancestral spawning grounds.<ref>{{cite news |title=Hooking the dinosaur of fish |date=2018-05-26 |newspaper=[[The New York Times]] |lang=en-US |issn=0362-4331 |url=https://www.nytimes.com/2018/05/26/science/paddlefish-caviar-conservation.html |access-date=2018-05-27 |df=dmy-all }}</ref>  Other detrimental effects include alterations of rivers which have changed natural flows resulting in the loss of spawning habitat and nursery areas.<ref name=NatGeo>{{cite web |title=Chinese paddlefish |website=[[National Geographic magazine|National Geographic]] |url=http://environment.nationalgeographic.com/environment/freshwater/chinese-paddlefish/ |access-date=May 28, 2014 |url-status=dead|archive-url=https://web.archive.org/web/20140714034603/http://environment.nationalgeographic.com/environment/freshwater/chinese-paddlefish/ |archive-date=July 14, 2014 |df=dmy-all }}</ref>