View source for Gharial

{{short description|Crocodilian native to the Indian subcontinent}}
{{good article}}
{{Speciesbox
|name = Gharial
|fossil_range = [[Pleistocene]]–Present, {{fossil_range|2.6|0|ref=<ref name="Rio2021">{{cite journal |last1=Rio |first1=J. P. |last2=Mannion |first2=P. D. |date=2021 |title=Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem |journal=[[PeerJ]] |volume=9 |article-number=e12094 | pmid=34567843 | doi=10.7717/peerj.12094 |pmc=8428266 |doi-access=free |name-list-style=amp}}</ref>}}
|status = CR
|status_system = IUCN3.1
|status_ref = <ref name=iucn>{{cite iucn |title=''Gavialis gangeticus'' |errata=2019 |name-list-style=amp |author1=Lang, J. |author2=Chowfin, S. |author3=Ross, J. P. |year=2019 |article-number=e.T8966A149227430 |access-date=22 January 2022}}</ref>
|status2 = CITES_A1 
|status2_system = CITES 
|status2_ref = <ref name=iucn/>
|image = Gharial (Gavialis gangeticus) male.jpg
|image_caption = Male gharial
|image2 = Gharial (Gavialis gangeticus) female.jpg
|image2_caption = Female and juvenile gharial
|genus = Gavialis
|species = gangeticus
|authority = ([[Johann Friedrich Gmelin|Gmelin]], 1789)
|range_map =The_range_of_the_Gharial.png
|range_map_caption = Range of gharial as of 2019 in black
|synonyms =
*''Lacerta gangetica'' {{small|Gmelin, 1789}}
*''Crocodilus gavial'' {{small|[[Pierre Joseph Bonnaterre|Bonnaterre]], 1789}}
*''Crocodilus longirostris'' {{small|[[Johann Gottlob Theaenus Schneider|Schneider]], 1801}}
*''Crocodilus arctirostris'' {{small|[[François Marie Daudin|Daudin]], 1802}}
*''Crocodilus gangeticus'' and ''C. tenuirostris'' {{small|[[Georges Cuvier|Cuvier]], 1807}}
*''Rhamphostoma'' {{small|[[Johann Georg Wagler|Wagler]], 1830}}
*''†Gharialis hysudricus'' {{small|[[Richard Lydekker|Lydekker]], 1886}}
|synonyms_ref =<ref name=Gray1896/>
}}

The '''gharial''' ('''''Gavialis gangeticus'''''), also known as '''gavial''' or '''fish-eating crocodile''', is a [[crocodilia]]n in the [[family (biology)|family]] [[Gavialidae]] and among the longest of all living crocodilians. Mature females are {{cvt|2.6|to|4.5|m|ftin}} long, and males {{cvt|3|to|6|m|ftin}}. Adult males have a distinct boss at the end of the snout, which resembles an earthenware pot known as a ''[[ghara]]'', hence the name "gharial". The gharial is well adapted to catching fish because of its long, narrow snout and 110 sharp, interlocking teeth.

The gharial probably evolved in the northern [[Indian subcontinent]]. Fossil gharial remains were excavated in [[Pliocene]] deposits in the [[Sivalik Hills]] and the [[Narmada River]] valley. It currently inhabits rivers in the plains of the northern part of the Indian subcontinent. It is the most thoroughly aquatic crocodilian, and leaves the water only for basking and building nests on moist sandbanks. Adults mate at the end of the cold season. Females congregate in spring to dig nests, in which they lay 20–95 eggs. They guard the nests and the young, which hatch before the onset of the [[monsoon]]. The hatchlings stay and forage in shallow water during their first year, but move to sites with deeper water as they grow.

The wild gharial population has declined drastically since the 1930s and is limited to only 2% of its historical range today. Conservation programmes initiated in India and Nepal focused on reintroducing captive-bred gharials since the early 1980s. [[Habitat loss|Loss of habitat]] because of [[sand mining]] and conversion to agriculture, depletion of fish resources and detrimental fishing methods continue to threaten the population. It has been listed as [[critically endangered]] on the [[IUCN Red List]] since 2007.

The oldest known depictions of the gharial are about 4,000 years old and were found in the [[Indus Valley]]. [[Hindus]] regard it as the vehicle of the river deity [[Ganga (goddess)|Gaṅgā]]. Local people living near rivers attributed mystical and healing powers to the gharial, and used some of its body parts as ingredients of [[indigenous medicine]].

== Etymology ==
The name 'gharial' is derived from the [[Hindustani language|Hindustani]] word '[[ghara]]' for an earthen pot, in reference to the nasal [[wiktionary:protuberance|protuberance]] on the adult male's snout. It is also called 'gavial'.<ref name=Stevenson2010>{{cite book |author=Stevenson, C. |author2=Whitaker, R. |author-link2=Romulus Whitaker |name-list-style=amp |year=2010 |chapter=Gharial ''Gavialis gangeticus'' |pages=139–143 |title=Crocodiles. Status Survey and Conservation Action Plan |edition=Third |editor1=Manolis, S. C. |editor2=Stevenson, C. |publisher=Crocodile Specialist Group |location=Darwin |chapter-url=http://www.iucncsg.org/365_docs/attachments/protarea/23_G-6764939a.pdf}}</ref> The name 'fish-eating crocodile' is a translation of its [[Bengali language|Bengali]] name 'mecho kumhir', with 'mecho' being derived from 'māch' meaning fish and 'kumhir' meaning crocodile.<ref name=Daniel1983>{{cite book |author=Daniel, J. C. |author-link=J. C. Daniel (naturalist) |year=1983 |chapter=Gharial, or Long-snouted Crocodile ''Gavialis gangeticus'' (Gmelin) |title=The Book of Indian Reptiles |pages=15–16 |location=Bombay and Oxford |publisher=Bombay Natural History Society and Oxford University Press |isbn=978-0-19-562168-6}}</ref> The name 'Indian gharial' has occasionally been used for gharial populations in India.<ref name=Bustard1977>{{cite journal |author1=Bustard, H. R. |author2=Singh, L. A. K. |name-list-style=amp |year=1977 |title=Studies on the Indian gharial ''Gavialis gangeticus'' (Gmelin) (Reptilia, Crocodilia) change in terrestrial locomotory pattern with age |journal=Journal of the Bombay Natural History Society |volume=74 |issue=3 |page=534−535 |url=https://archive.org/details/journalofbombay741977bomb/page/534}}</ref>

==Taxonomy==
''Lacerta gangetica'' was the [[scientific name]] proposed by [[Johann Friedrich Gmelin]] in 1789.<ref>{{cite book |author=Gmelin, J. F. |year=1789 |title=Caroli a Linné. Systema naturae per regna tria naturae: secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis |trans-title=Carol Linné. The System of Nature by the three Kingdoms of Nature: according to classes, orders, genera, species with characteristics, differences, synonyms, places |volume=((Tomus I. Pars III)) |publisher=G. E. Beers |location=Leipzig |chapter=''Lacerta gangetica ''|pages=1057–1058 |language=la |chapter-url=https://archive.org/details/carolilinns01linn/page/1057}}</ref> Gmelin followed [[Carl Linnaeus]] who proposed ''Lacerta'' in 1758 to include other [[crocodile]]s and various [[lizards]] known at the time.<ref>{{cite book |author=Linnaeus, C. |year=1758 |title=Caroli Linnæi Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis |volume=((Tomus I)) |edition=decima, reformata |location=Holmiae |publisher=Laurentius Salvius |language=la |page=41−42 |chapter=Lacerta |chapter-url=https://archive.org/stream/mobot31753000798865#page/200/mode/2up}}</ref>

The gharial was placed in the [[genus]] ''[[Crocodilus]]'' by subsequent naturalists:
*''Crocodilus gavial'' by [[Pierre Joseph Bonnaterre]] in 1789.<ref>{{cite book |author=Bonnaterre, P. J. |year=1789 |title=Tableau encyclopédique et méthodique des trois règnes de la nature. Erpétologie |trans-title=Encyclopedic and methodical plates of the three Kingdoms of Nature. Herpetology |publisher=Chez Panckoucke |location=Paris |chapter=''Le Gavial ''|pages=34–35 |chapter-url=https://archive.org/details/tableauencyclo00bonn/page/34 |language=fr}}</ref>
*''Crocodilus longirostris'' by [[Johann Gottlob Theaenus Schneider]] in 1801.<ref>{{cite book |author=Schneider, J. G. T. |year=1801 |title=Historiae amphibiorum naturalis et literariae fasciculus secundus |trans-title=Natural History of and Literature about the Amphibians |publisher=F. Frommann |location=Jena |chapter=''Longirostris ''|pages=160–161 |chapter-url=https://archive.org/details/historiaeamphibi02schn/page/160 |language=la}}</ref>
*''Crocodilus arctirostris'' by [[François Marie Daudin]] in 1802.<ref>{{cite book |author=Daudin, F. M. |year=1802 |title=Histoire Naturelle, Générale et Particulière des Reptiles; ouvrage faisant suit à l'Histoire naturelle générale et particulière, composée par Leclerc de Buffon; et rédigee par C.S. Sonnini, membre de plusieurs sociétés savantes |volume=((Tome 2)) |publisher=F. Dufart |location=Paris |chapter=Le crocodile à bec étroit ou le grand Gavial [The straight-snouted crocodile or the great Gavial] |pages=393–396 |language=fr |chapter-url=https://archive.org/details/histoirenaturel121802daud/page/392}}</ref>
*''Longirostres'' was a subgroup proposed by [[Georges Cuvier]] in 1807 for crocodiles with a long snout. He placed ''Crocodilus gangeticus'' with the [[Type locality (biology)|type locality]] "Ganges" and ''Crocodilus tenuirostris'' without locality into this group.<ref>{{cite journal |author=Cuvier, G. |year=1807 |title=Sur les différentes espèces de crocodiles vivans et sur leurs caractères distinctifs |trans-title=About the different species of the living crocodiles and their distinct characteristics |journal=Annales du Muséum National d'Histoire Naturelle |volume=10 |pages=8–66 |language=fr |url=https://archive.org/details/annalesdumusum10mus/page/66}}</ref>

The [[Genus (biology)|generic]] name ''[[Gavialis]]'' was proposed by [[Nicolaus Michael Oppel]] in 1811 for crocodiles with a cylindrical-shaped back. He placed this genus in the family Crocodilini.<ref>{{cite book |author=Oppel, N. M. |year=1811 |title=Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben |publisher=J. Lindauer |location=München |chapter=''Familia''. Crocodilini |page=19 |language=de |chapter-url=https://archive.org/details/dieordnungenfami00oppe/page/19}}</ref>
''Rhamphostoma'' was proposed by [[Johann Georg Wagler]] in 1830 who considered this genus to contain two species, ''Crocodilus gangeticus'' and ''C. tenuirostris''.<ref>{{cite book |author=Wagler, J. |year=1830 |title=Natürliches System der Amphibien, mit vorangehender Classification der Säugethiere und Vögel. Ein Beitrag zur vergleichenden Zoologie |trans-title=A natural System of the Amphibiae, preceded by a Classification of the Mammalia and Birds. A contribution to comparative Zoology |publisher=J. G. Cotta'scche Buchhandlung |location=München |chapter=''Rhamphostoma ''|page=141 |language=de |chapter-url=https://archive.org/details/natrlichessystem00wagl/page/141}}</ref>

The family name [[Gavialidae]] was proposed by [[Arthur Adams (zoologist)|Arthur Adams]] in 1854 with ''Gavialis'' as the only genus in this family.<ref>{{cite book |author1=Adams, A. |year=1854 |title=A Manual of Natural History, for the Use of Travellers: Being a Description of the Families of the Animal and Vegetable Kingdoms: with Remarks on the Practical Study of Geology and Meteorology |location=London |publisher=John Van Voorst |editor1=Adams, A. |editor2=Baikie, W. B. |editor3=Barron, C. |chapter=II. Order{{Snd}} Emydosaurians (Emydosauria) |pages=70–71 |chapter-url=https://books.google.com/books?id=71FAAAAAIAAJ&pg=PA70}}</ref>
''Gavialis gangetica'' was the scientific name used by [[Albert Günther]] in 1864 who considered ''L. gangetica'', ''C. longirostris'' and ''C. tenuirostris'' as [[Synonym (taxonomy)|synonym]]s and ''Gavialis'' a [[monotypic taxon]].<ref>{{cite book |author=Günther, A. |year=1864 |title=The reptiles of British India |publisher=Robert Hardwicke |location=London |chapter=''Gavialis'', Geoffr. |page=63 |chapter-url=https://archive.org/details/reptilesofbritis00gn/page/63}}</ref> [[John Edward Gray]] reviewed [[zoological specimen]]s in the collection of the [[Natural History Museum, London]]. He also considered the gharial monotypic in 1869. He placed it in the family Gavialidae together with the [[false gharial]] (''Tomistoma schlegelii'') because both have long, slender jaws and similar dentition.<ref name=Gray1896>{{cite journal |author=Gray, J. E. |year=1869 |title=Synopsis of the species of recent Crocodilians or Emydosaurians, chiefly founded on the specimens in the British Museum and the Royal College of Surgeons |journal=The Transactions of the Zoological Society of London |volume=6 |issue=4 |pages=125–169 |url=https://archive.org/details/transactionsofzo06zool/page/132 |doi=10.1111/j.1096-3642.1867.tb00575.x}}</ref>

''Gharialis hysudricus'' proposed by [[Richard Lydekker]] in 1886 was based on a fossil skull from the [[Sivalik Hills]] that was larger than gharial fossil skulls known at the time.<ref>{{cite book |author=Lydekker, R. |year=1886 |title=Memoirs of the Geological Survey of India |series=Indian Tertiary and post Tertiary Vertebrata |volume=III |location=Calcutta |publisher=Geological Survey Office |pages=222–223 |chapter=''Gharialis hysudricus'' |chapter-url=https://archive.org/details/indiantertiarypo03foot/page/222/mode/2up}}</ref> This name is considered to be a [[junior synonym]] of ''Gavialis gangeticus''.<ref name=Martin2018>{{Cite journal |last=Martin|first=J. E. |year=2018 |title=The taxonomic content of the genus ''Gavialis'' from the Siwalik Hills of India and Pakistan |journal=Papers in Palaeontology |volume=5 |issue=3 |pages=483–497 |doi=10.1002/spp2.1247|bibcode=2019PPal....5..483M |s2cid=134966832 |url=https://hal.archives-ouvertes.fr/hal-02123647/file/2019Gavialis.pdf}}</ref>

==Evolution==
The evolution of the gharial and its relationship with and divergence from other crocodilians have been a subject of controversy.<ref name=Brochu97>{{cite journal |author=Brochu, C. A. |year=1997 |title=Morphology, fossils, divergence timing, and the phylogenetic relationships of ''Gavialis'' |journal=Systematic Biology |volume=46 |issue=3 |pages=479–522 |pmid=11975331 |doi=10.1093/sysbio/46.3.479|doi-access= }}</ref> Some authors assumed that the gharial evolved earlier than the other crocodilians because of its distinct skull shape and dentition, indicating a more advanced level of specialization.<ref>{{cite journal |author1=Kälin, J. A. |year=1931 |title=Über die Stellung der Gavialiden im System der Crocodilia |trans-title=On the position of the Gavialids in the system of the Crocodilia |journal=[[Revue suisse de Zoologie]] |volume=38 |issue=3 |pages=379–388 |url=https://archive.org/details/revuesuissedezoo3819schw/page/n451/mode/2up}}</ref><ref>{{cite journal |author1=Hecht, M. K. |author2=Malone, K. |year=1972 |title=On the Early History of the Gavialid Crocodilians |journal=Herpetologica |volume=28 |issue=3 |pages=281–284 |jstor=3890639}}</ref> Others suggested that it evolved much later than other crocodilians because of its low levels of [[blood protein]] divergence. As it shares this trait with the false gharial, it was suggested that they form a [[sister group]].<ref>{{cite journal |author1=Densmore III, L. D. |author2=Dessauer, H. C. |name-list-style=amp |year=1984 |title=Low levels of protein divergence detected between ''Gavialis'' and ''Tomistoma'': evidence for crocodilian monophyly? |journal=Comparative Biochemistry and Physiology Part B: Comparative Biochemistry |volume=77 |issue=4 |pages=715–720 |doi=10.1016/0305-0491(84)90302-X}}</ref> In contrast, it was suggested that the gharial and all the other crocodilians form a sister group as the structure of its tail muscles is unique.<ref>{{cite journal |author1=Frey, E. |author2=Riess, J. |author3=Tarsitano, S. F. |name-list-style=amp |year=1989 |title=The axial tail musculature of recent crocodiles and its phyletic implications |journal= American Zoologist |volume=29 |issue=3 |pages=857–862 |url=https://academic.oup.com/icb/article-pdf/29/3/857/831972/29-3-857.pdf |doi=10.1093/icb/29.3.857}}</ref> [[Sequencing]] of a [[ribosomal]] segment of [[mitochondrial DNA]]s of gharial and false gharial revealed that they share 22 unique [[nucleotide]]s, a similarity of 94%, supporting the view that they are sister taxa.<ref>{{cite journal |author1=Gatesy, J. |author2=Amato, G. D. |name-list-style=amp |year=1992 |title=Sequence Similarity of 12S Ribosomal Segment of Mitochondrial DNAs of Gharial and False Gharial |journal=Copeia |volume=1992 |issue=1 |pages=241–243 |doi=10.2307/1446560 |jstor=1446560}}</ref>  Analyses of [[nuclear gene]] sequences of both species also support the view that they are sister taxa.<ref name="Harshman2003">{{cite journal |pmid=12775527 |year=2003 |last1=Harshman |first1=J. |title=True and false gharials: A nuclear gene phylogeny of crocodylia |journal=Systematic Biology |volume=52 |issue=3 |pages=386–402 |last2=Huddleston |first2=C. J. |last3=Bollback |first3=J. P. |last4=Parsons |first4=T. J. |last5=Braun |first5=M. J. |doi=10.1080/10635150309323 |doi-access=free }}</ref><ref>{{Cite journal |author1=Willis, R. E. |author2=McAliley, L. R. |author3=Neeley, E. D. |author4=Densmore Ld, L. D. |name-list-style=amp |title=Evidence for placing the false gharial (''Tomistoma schlegelii'') into the family Gavialidae: Inferences from nuclear gene sequences |date=2007 |journal=Molecular Phylogenetics and Evolution |volume=43 |issue=3 |pages=787–794 |doi=10.1016/j.ympev.2007.02.005 |pmid=17433721|bibcode=2007MolPE..43..787W }}</ref> [[Molecular genetics]] and [[tip dating]] studies indicates a [[genetic divergence]] between the gharial and false gharial in the [[Eocene]] about {{mya|38}}.<ref name="LeeYates2018">{{cite journal |author=Lee, M. S. Y. |author2=Yates, A. M. |date=2018 |title=Tip-dating and homoplasy: reconciling the shallow molecular divergences of modern gharials with their long fossil record |journal=[[Proceedings of the Royal Society B]] |volume=285 |issue=1881 |doi=10.1098/rspb.2018.1071 |pmid=30051855 |pmc=6030529 |doi-access=free}}</ref>

The genus ''[[Gavialis]]'' probably originated in the region of India and Pakistan in the [[Early Miocene]].<ref name=Delfino>{{Cite journal |last1=Delfino |first1=M. |last2=De Vos |first2=J. |name-list-style=amp |year=2010 |title=A revision of the Dubois crocodylians, ''Gavialis bengawanicus'' and ''Crocodylus ossifragus'', from the Pleistocene ''Homo erectus'' beds of Java |journal=Journal of Vertebrate Paleontology |volume=30 |issue=2 |page=427 |doi=10.1080/02724631003617910 |bibcode=2010JVPal..30..427D |s2cid=86396515}}</ref> Fossil gharial remains excavated in the [[Sivalik Hills]] of [[Haryana]] and [[Himachal Pradesh]] are dated to between the [[Pliocene]] and the [[Early Pleistocene]].<ref>{{cite journal |author1=Patnaik, R. |author2=Schleich, H. H. |name-list-style=amp |year=1993 |title=Fossil crocodile remains from the Upper Siwaliks of India |journal=Mitteilungen der Bayerischen Staatssammlung für Paläontologie und historische Geologie |issue=33 |pages=91–117 |url=https://archive.org/details/mitteilungenderb313319911993baye/page/90}}</ref> Fossil gharial remains were also found at two sites in the [[Ayeyarwady River]] valley in central Myanmar, which are dated to the [[Late Pleistocene]].<ref name=WinKoKo>{{cite journal |author1=Win Ko Ko |author2=Platt, S. G. |name-list-style=amp |year=2012 |title=Does the Gharial (''Gavialis gangeticus'') survive in Myanmar? |journal=Crocodile Specialist Group Newsletter |volume=32 |issue=4 |pages=14–16 |url=http://www.iucncsg.org/365_docs/attachments/protarea/News-153f3fd2.pdf#page=14}}</ref>
During the [[Quaternary]], ''Gavialis'' dispersed as far as [[Java]] via the Siva–[[Malay Peninsula|Malayan]] route, which did not require saltwater crossings. Fossil remains of ''[[Gavialis bengawanicus]]'' found on Java were dated to the Early Pleistocene.<ref name=Delfino/>
''G. bengawanicus'' fossils found in Thailand's [[Nakhon Ratchasima Province]] support the hypothesis of gharial dispersal through riverine systems.<ref>{{cite journal |author1=Martin, J. E. |author2=Buffetaut, E. |author3=Naksri, W. |author4=Lauprasert, K. |author5=Claude, J. |name-list-style=amp |year=2012 |title=''Gavialis'' from the Pleistocene of Thailand and its relevance for drainage connections from India to Java |journal=PLOS ONE |volume=7 |issue=9 |article-number=e44541 |doi=10.1371/journal.pone.0044541|pmid=23028557 |pmc=3445548 |bibcode=2012PLoSO...744541M |doi-access=free }}</ref> It represents the only valid extinct ''Gavialis'' species.<ref>{{cite journal |author=Martin, J. E. |year=2019 |title=The taxonomic content of the genus ''Gavialis'' from the Siwalik Hills of India and Pakistan |journal=Papers in Palaeontology |volume=5 |issue=3 |pages=483–497 |doi=10.1002/spp2.1247 |bibcode=2019PPal....5..483M |s2cid=134966832 |url=https://hal.archives-ouvertes.fr/hal-02123647/file/2019Gavialis.pdf}}</ref>

=== Phylogeny ===
The below [[cladogram]] of the major [[extant taxon|extant]] crocodile groups is based on the latest molecular studies and shows the gharial's close relationship to the false gharial, and how the [[gavialids]] and [[crocodiles]] are more closely related than the [[alligatoroids]]:<ref name=Harshman2003/><ref name=Gatesy2008>{{cite journal|last1=Gatesy |first1=J. |last2=Amato |first2=G. |name-list-style=amp |year=2008 |title=The rapid accumulation of consistent molecular support for intergeneric crocodylian relationships |journal=[[Molecular Phylogenetics and Evolution]]|volume=48 |issue=3 |pages=1232–1237 |doi=10.1016/j.ympev.2008.02.009|pmid=18372192|bibcode=2008MolPE..48.1232G }}</ref><ref name=Erickson_al2012>{{cite journal |author=Erickson, G. M. |author2=Gignac, P. M. |author3=Steppan, S. J. |author4=Lappin, A. K. |author5=Vliet, K. A. |author6=Brueggen, J. A. |author7=Inouye, B. D. |author8=Kledzik, D. |author9=Webb, G. J. W. |name-list-style=amp |year=2012 |title=Insights into the ecology and evolutionary success of crocodilians revealed through bite-force and tooth-pressure experimentation |journal=PLOS ONE |volume=7 |issue=3 |article-number=e31781 |doi=10.1371/journal.pone.0031781 |bibcode=2012PLoSO...731781E |pmid=22431965 |pmc=3303775 |doi-access=free}}</ref><ref name=LeeYates2018/><ref name=Hekkala2021>{{Cite journal|last1=Hekkala |first1=E. |last2=Gatesy |first2=J. |last3=Narechania |first3=A. |last4=Meredith |first4=R. |last5=Russello |first5=M. |last6=Aardema |first6=M. L. |last7=Jensen |first7=E. |last8=Montanari |first8=S. |last9=Brochu |first9=C. |last10=Norell |first10=M. |last11=Amato |first11=G. |date=2021 |title=Paleogenomics illuminates the evolutionary history of the extinct Holocene "horned" crocodile of Madagascar, ''Voay robustus'' |journal=Communications Biology |volume=4 |issue=1 |page=505 |doi=10.1038/s42003-021-02017-0 |pmid=33907305 |pmc=8079395 |doi-access=free}}</ref>
{{clade| style=font-size:85%;line-height:85%
|label1='''[[Crocodilia]]'''
|1={{clade
   |label1=[[Alligatoridae]]
   |1={{clade
      |label1=[[Caimaninae]]
        |1={{clade
           |1={{clade
              |1=''[[Caiman (genus)|Caiman]]'' [[File:Caiman crocodilus llanos white background.JPG|90 px]]
              |2=''[[Melanosuchus]]'' [[File:Melanosuchus niger white background.jpg|120 px]] }}
           |2=''[[Paleosuchus]]'' [[File:Dwarf Caiman white background.jpg|90 px]] }}
      |label2=[[Alligatorinae]]
        |2=''[[Alligator]]'' [[File:Alligator white background.jpg|100 px]] }}
   |label2=[[Longirostres]]
   |2={{clade
   |label1=[[Crocodylidae]]
   |1={{clade
      |1=''[[Crocodylus]]'' [[File:Siamese Crocodile white background.jpg|90 px]]
      |2={{clade
         |1=''[[Mecistops]]'' [[File:Crocodylus cataphractus faux-gavial d'Afrique2 white background.JPG|90 px]]
         |2=''[[Osteolaemus]]'' [[File:Bristol.zoo.westafrican.dwarf.croc.arp. white background.jpg|90 px]] }} }}
   |label2=[[Gavialidae]]
   |2={{clade
      |1='''''[[Gavialis]]''''' [[File:Gavialis gangeticus (Gharial, Gavial) white background.jpg|110 px]]
      |2=''[[Tomistoma]]'' [[File:Tomistoma schlegelii. white background.JPG|90 px]]
}} }} }} }}

Here is a more detailed cladogram that shows the gharial's proposed placement within [[Gavialidae]], including [[extinct]] members:<ref name=LeeYates2018/>

{{clade| style=font-size:85%;line-height:85%
|label1='''[[Gavialidae]]'''
|1={{clade
 |1={{clade
  |1={{clade
   |1={{clade
    |1={{clade
     |1={{clade
      |1={{clade
       |1={{clade
        |1='''Gharial''' 
        |2=''[[Gavialis bengawanicus]]''{{extinct}} }}
       |2=''[[Gavialis browni]]''{{extinct}} }}
      |2=''[[Gryposuchus colombianus]]''{{extinct}} }}
     |2=''[[Ikanogavialis]]''{{extinct}} }}
    |2={{clade
     |1=''[[Gryposuchus pachakamue]]''{{extinct}}
     |2=''[[Piscogavialis]]''{{extinct}} }} }}
    |2=''[[Harpacochampsa]]''{{extinct}} }}
  |2={{clade
   |1={{clade
    |1=''[[Toyotamaphimeia]]''{{extinct}}
    |2=''[[Penghusuchus]]''{{extinct}} }}
   |2=''[[Gavialosuchus]]''{{extinct}} }} }}
 |2={{clade
  |1=''[[Tomistoma lusitanicum]]''{{extinct}}
  |2='''[[False gharial]]''' ''Tomistoma schlegelii'' }} }} }}

==Characteristics==
{{multiple image |direction=vertical |image1=Gharial (Gavialis gangeticus) female head.jpg |caption1=Adult female gharial |image2=Indian Gharial at the San Diego Zoo (2006-01-03) (headshot).jpg |caption2=Adult male gharial |image3=Gavial Skeleton.jpg |caption3=Gharial [[skeleton]]}}
The gharial is olive-coloured, with adults being darker than young, which have dark brown cross bands and speckles.<ref name=Boulenger>{{cite book |author=Boulenger, G. A. |author-link=George Albert Boulenger |year=1889 |title=Catalogue of the Chelonians, Rhynchocephalians, and Crocodiles in the British Museum (Natural History) |location=London |publisher=Trustees of the British Museum (Natural History) |edition=New |pages=275–276 |chapter=''Gavialis'' |chapter-url=https://archive.org/details/catalogueofchelo00brituoft/page/275}}</ref><ref>{{cite book |author=Boulenger, G. A. |year=1890 |title=Fauna of British India. Reptilia and Batrachia |publisher=Taylor and Francis |location=London |chapter=Genus ''Gavialis'' |page=3 |chapter-url=https://archive.org/details/reptiliabatrachi00boul/page/3}}</ref> Its back turns almost black at 20 years of age, but its belly is yellowish-white. It has four transverse rows of two [[Scale (anatomy)|scales]] on the neck, which continue along the back.<ref name=Brazaitis>{{cite journal |author=Brazaitis, P. |year=1973 |title=Family Gavialidae ''Gavialis gangeticus'' Gmelin |journal=Zoologica |volume=3 |page=80−81 |url=https://archive.org/details/zoologicascie58341973newy/page/80}}</ref> [[Scute]]s on the head, neck and back form a single continuous plate composed of 21 to 22 transverse series, and four longitudinal series. Scutes on the back are bony, but softer and feebly keeled on the sides. The outer edges of the forearms, legs, and feet have crests jutting out; fingers and toes are partly webbed.<ref name=Boulenger/>

Its snout is very long and narrow, widened at the end, and has 27 to 29 upper teeth and 25 or 26 lower teeth on each side. The front teeth are the largest. The first, second, and third lower jaw teeth fit into spaces in the upper jaw. The extremely long [[mandibular symphysis]] extends to the 23rd or 24th tooth. The snout of adult gharials is 3.5 times longer than the width of the skull's base.<ref name=Boulenger/> Because of this long snout, the gharial is especially adapted to catching and eating fish.<ref name=Stevenson2010 /> The [[nasal bone]]s are rather short and widely spaced from the [[premaxilla]]e. The [[jugal bone]] is raised.<ref name=Boulenger/> It becomes proportionally thicker with age.<ref name=Whitaker07/>
Two individuals in the weight range of {{cvt|103-121|kg}} had an average measured [[bite force]] of {{cvt|1784-2006|N|lk=on}}.<ref name=Erickson_al2012/>

Male gharials develop a hollow bulbous nasal protuberance at the tip of the snout upon reaching [[sexual maturity]].<ref name=Brazaitis/> This protuberance resembles an earthen pot known locally as "ghara". The male's ghara starts growing over the [[nostril]]s at an age of 11.5 years and measures about {{cvt|5|x|6|x|3.5|cm}} at an age of 15.5 years. It enables the males to emit a hissing sound that can be heard {{cvt|75|m}} away; this sound is thought to attract females.<ref name=Biswas1977>{{cite journal |author1=Biswas, S. |author2=Acharjyo, L. N. |author3=Mohapatra, S. |name-list-style=amp |year=1977 |title=A note on the protuberance or knob on the snout of male gharial, ''Gavialis gangeticus'' (Gmelin) |journal=Journal of the Bombay Natural History Society |volume=74 |issue=3 |pages=536–537 |url=https://archive.org/details/journalofbombay741977bomb/page/536}}</ref>
The gharial is the only living crocodilian with such visible [[sexual dimorphism]].<ref name=Whitaker07>{{cite journal |author=Whitaker, R. |author2=Members of the Gharial Multi-Task Force |author3=Madras Crocodile Bank |year=2007 |title=The Gharial: Going Extinct Again |journal=Iguana |volume=14 |issue=1 |pages=24–33 |url=http://www.ircf.org/downloads/Iguana14_1%20Gharial%20Going%20Extinct%20Again.pdf |archive-url=https://web.archive.org/web/20110726191641/http://www.ircf.org/downloads/Iguana14_1%20Gharial%20Going%20Extinct%20Again.pdf |archive-date=2011-07-26 }}</ref>
Mature male gharials have larger [[skull]]s than females, exceeding a basal length of {{cvt|715|mm}} and a width of {{cvt|287|mm}}.<ref>{{cite journal |last1=Hone |first1=D. |last2=Mallon |first2=J.C. |last3=Hennessey |first3=P. |first4=L.M. |last4=Witmer |name-list-style=amp |year=2020 |title=Ontogeny of a sexually selected structure in an extant archosaur ''Gavialis gangeticus'' (Pseudosuchia: Crocodylia) with implications for sexual dimorphism in dinosaurs |journal=PeerJ |volume=8 |article-number=e9134 |doi=10.7717/peerj.9134|pmid=32435543 |pmc=7227661 |doi-access=free}}</ref>

Female gharials reach sexual maturity at a body length of {{cvt|2.6|m}} and grow up to {{cvt|4.5|m}}. Males mature at a body length of at least {{cvt|3|m}} and grow up to a length of {{cvt|6|m}}.<ref name=Whitaker1982>{{cite journal |author1=Whitaker, R. |author2=Basu, D. |name-list-style=amp |year=1982 |title=The Gharial (''Gavialis gangeticus''): A review |journal=Journal of the Bombay Natural History Society |volume=79 |issue=3 |pages=531–548 |url=https://www.biodiversitylibrary.org/page/48239318#page/584/mode/1up}}</ref> Adult males weigh about {{cvt|160|kg}} on average, but large males can reach a weight of {{cvt|600|-|750|kg}}.<ref name=Stevenson2010/><ref>{{cite journal |author1=Gauthier, J. A. |author2=Nesbitt, S. J. |author3=Schachner, E. R. |author4=Bever, G. S. |author5=Joyce, W. G. |name-list-style=amp |title=The bipedal stem crocodilian ''Poposaurus gracilis'': inferring function in fossils and innovation in archosaur locomotion |date=2011 |journal=Bulletin of the Peabody Museum of Natural History |volume=52 |issue=1 |pages=107–126 |doi=10.3374/014.052.0102 |bibcode=2011BPMNH..52..107G |s2cid=86687464 |url=https://www.researchgate.net/publication/229181586}}</ref><ref>{{cite journal |last1=Ajji, M. |first1=J. |last2=Lang |first2=J. W. |title=Gharial acoustic signaling: Novel underwater pops are temporally based, context-dependent, seasonally stable, male-specific, and individually distinctive |journal=Journal of Anatomy |date=2025 |volume=246 |issue=3 |pages=415–443 |doi=10.1111/joa.14171|pmid=39887971 |pmc=11828749 |name-list-style=amp}}</ref> The gharial is among the largest living crocodilians, with the heaviest recorded male weighing {{cvt|977|kg}}.<ref name=maskey94/>
A {{cvt|6.55|m}} long gharial was claimed to have been killed in the [[Ghaghara River]] in [[Faizabad]] in August 1920, though no reliable measurements were taken.<ref>{{cite journal |author=Pitman, C. R. S. |author-link=Charles Pitman (game warden) |year=1925 |title=The length attained by and the habits of the Gharial (''G. gangeticus'') |journal=Journal of the Bombay Natural History Society |volume=30 |issue=3 |page=703 |url=https://archive.org/details/journalofbomb30341925bomb/page/703}}</ref> Male gharials with an alleged length of {{cvt|7.16|to|9.14|m}} were sighted around the turn of the 20th century in Indian rivers.<ref>{{cite book |author=Flower, S. S. |year=1914 |title=Report on a zoological mission to India in 1913 |location=Cairo |publisher=Ministry of Public Works |chapter=The Gharial, ''Garialis gangeticus'' |page=21 |chapter-url=https://archive.org/details/flowerzoologicalmissi1913/page/20/mode/2up}}</ref><!-- these were not shot and measured, hunter lores? --> Overall, the gharial is less massive when compared to other crocodilians of similar length; a {{cvt|4.9|m}} long gharial weighed around {{cvt|560|kg}}, while a {{cvt|4.8|m}} long [[Nile crocodile]] weighed {{cvt|680|kg|lb}}.<ref>{{cite book |last1=Wood |first1=G. L. |title=The Guinness book of animal facts and feats |date=1982 |publisher=Guinness Superlatives |location=Enfield, Middlesex |isbn=978-0-85112-235-9 |page=98 |edition=3rd}}</ref>

==Distribution and habitat==
{{multiple image |direction=vertical |image1=Gharial_in_Karnali.JPG |caption1=Gharials in Karnali River, Nepal, with a [[mugger crocodile]] in the back |image2=Big Mama National Chambal sanctuary 01.jpg |caption2=Gharial in National Chambal Sanctuary}}
The gharial once thrived in all the major river systems of the northern Indian subcontinent, from the [[Indus River]] in [[Pakistan]], the [[Ganges]] in India, the [[Brahmaputra River]] in [[northeastern India]] and [[Bangladesh]] to the [[Irrawaddy River]] in [[Myanmar]].<ref name=Whitaker07/> 
In the early 20th century, it was considered common in the Indus River and its [[Punjab, Pakistan|Punjabi]] tributaries.<ref>{{cite journal |author=Francis, R. |year=1911 |title=The broad snouted Mugger in the Indus |journal=Journal of the Bombay Natural History Society |volume=20 |issue=4 |page=11601162 |url=https://archive.org/details/journalofbombayn20191011bomb/page/1160/mode/2up}}</ref><ref>{{cite journal |author1=Rao, C. J. |year=1933 |title=Gavial on the Indus |journal=Journal of the Sind Natural History Society |volume=1 |issue=4 |page=37}}</ref> By the early 1980s, it was almost extinct in the Indus.<ref name=Whitaker1982/> During surveys in 2008 and 2009, no gharial was sighted in the river.<ref name=Stevenson2010/>
It was also present in India's [[Godavari River]] but was hunted to extinction between the late 1940s and the 1960s.<ref>{{cite journal |author1=Bustard, H. R. |author2=Choudhury, B. C. |name-list-style=amp |year=1983 |title=The distribution of the Gharial |journal=Journal of the Bombay Natural History Society |volume=79 |issue=2 |pages=427–429 |url=https://archive.org/details/journalofbombay791982bomb/page/428}}</ref>
It was considered extinct in the [[Koshi River]] since 1970.<ref>{{cite journal |author1=Biswas, S. |year=1970 |title=A Preliminary Survey of the Gharial in the Kosi River |journal=Indian Forester |volume=96 |issue=9 |pages=705–710}}</ref>
In the 1940s, it was numerous in the [[Barak River]] in [[Assam]], which held big fish at the time including [[golden mahseer]] (''Tor putitora'').<ref>{{cite journal |author=Macdonald, A. S. J. |year=1944 |title=Circumventing the Mahseer and Other Sporting Fish in India. Part VI: Mahseer Fishing in Assam and the Dooars |journal=Journal of the Bombay Natural History Society |volume=44 |issue=3 |pages=322–354 |url=https://archive.org/details/journalofbo4419431944bomb/page/322/mode/2up}}</ref>
A few individuals were also sighted in tributaries of the Barak River in Assam, [[Mizoram]] and [[Manipur]] up to 1988, but surveys were not carried out.<ref>{{cite journal |author1=Choudhury, A. U. |year=1997 |title=Records of the gharial ''Gavialis gangeticus'' (Gmelin) from the Barak river system of north-eastern India |journal=Journal of the Bombay Natural History Society |volume=94 |issue=1 |pages=162–164 |url=https://archive.org/details/journalofbombay941997bomb/page/162}}</ref>
In 1927, a gharial was shot in the [[Shweli River]] in Myanmar, a tributary of the Ayeyawady River.<ref>{{cite journal |author1=Barton, C. G. |year=1929 |title=The Occurrence of the Gharial (''Gavialis gangeticus'') in Burma |journal=Journal of the Bombay Natural History Society |volume=33 |issue=2 |pages=450–451 |url=https://archive.org/details/journalofbomb33121929bomb/page/450/mode/2up}}</ref> This is the only authenticated record in the country attesting the survival of gharials into the 20th century. Whether gharials still live in the Shweli River today is possible but remained unclear in 2012.<ref name=WinKoKo/>

By 1976, its global range had decreased to only 2% of its historical range, and fewer than 200 gharials were estimated to survive.<ref name=Whitaker07/> It is [[locally extinct]] in Pakistan, [[Bhutan]] and Myanmar.<ref name=Stevenson2010/>
Since the early 1980s, the population has been reinforced with captive-bred gharials that were released into wild habitats in India and Nepal.<ref name=iucn/> As of 2019, the global population was estimated to comprise at maximum 900 individuals, including about 600 mature adults in six major subpopulations along {{cvt|1100|km}} of river courses and another 50 mature adults in eight minor subpopulations along {{cvt|1200|km}} of river courses.<ref name=iucn /><!-- By 2025, the gharial population in India has grown to 3,044 individuals, with the majority of 2,456 in the State of [[Madhya Pradesh]].<ref>{{Cite web |title=Chambal River is home to more than 80 percent of the country's gharials |author=Joshi, K.K. |work=MP Info |year=2025 |url=https://www.mpinfo.org/Home/TodaysNews?newsid=20250103N310&fontname=FontEnglish&LocID=32&pubdate=01/03/2025 |access-date=2025-05-11}}</ref> -->

In Nepal, small populations are present and slowly recovering in tributaries of the Ganges, such as the [[Karnali River|Karnali]]–[[Babai River]] system in [[Bardia National Park]]<ref name=maskey94>{{cite book |author1=Maskey, T. M. |author2=Percival, H. F. |name-list-style=amp |year=1994 |chapter=Status and Conservation of Gharial in Nepal |title=Crocodiles. Proceedings of the 12th Working Meeting of the Crocodile Specialist Group convened at Pattaya, Thailand, 2–6 May 1994 |location=Gland |publisher=IUCN Crocodile Specialist Group |pages=77–83 |chapter-url=http://www.iucncsg.org/365_docs/attachments/protarea/12th-634937f9.pdf#page=90 |archive-date=30 December 2020 |access-date=23 January 2020 |archive-url=https://web.archive.org/web/20201230133805/http://www.iucncsg.org/365_docs/attachments/protarea/12th-634937f9.pdf#page=90 |url-status=dead }}</ref><ref name=Bashyal_al2021>{{cite journal |author1=Bashyal, A. |name-list-style=amp |author2=Shrestha, S. |author3=Luitel, K.P. |author4=Yadav, B.P. |author5=Khadka, B. |author6=Lang, J.W. |author7=Densmore, L.D. |year=2021 |title=Gharials (''Gavialis gangeticus'') in Bardiya National Park, Nepal: Population, habitat and threats |journal=Aquatic Conservation: Marine and Freshwater Ecosystems |volume=31 |issue=9 |pages=2594–2602 |doi=10.1002/aqc.3649|bibcode=2021ACMFE..31.2594B |s2cid=237803213 }}</ref> and the [[Narayani River|Narayani]]–Rapti river system in [[Chitwan National Park]].<ref>{{cite report |author=Priol, P. |year=2003 |title=Gharial field study report |location=Kathmandu |publisher=Department of National Parks and Wildlife Conservation}}</ref><ref name=Ballouard_al2010>{{cite journal |author=Ballouard, J. M. |author2=Priol, P. |author3=Oison, J. |author4=Ciliberti, A. |author5=Cadi, A. |name-list-style=amp |year=2010 |title=Does reintroduction stabilize the population of the critically endangered gharial (''Gavialis gangeticus'', Gavialidae) in Chitwan National Park, Nepal? |journal=Aquatic Conservation: Marine and Freshwater Ecosystems |volume=20 |issue=7 |pages=756–761 |url=https://www.researchgate.net/publication/227989979 |doi=10.1002/aqc.1151|bibcode=2010ACMFE..20..756B }}</ref>
In spring 2017, the Babai River was surveyed using an [[unmanned aerial vehicle]], which detected 33 gharials on a stretch of {{cvt|102|km}}.<ref>{{cite journal |author1=Thapa, G. J. |author2=Thapa, K. |author3=Thapa, R. |author4=Jnawali, S. R. |author5=Wich, S. A. |author6= Poudyal, L. P. |author7=Karki, S. |name-list-style=amp |year=2018 |title=Counting crocodiles from the sky: monitoring the critically endangered gharial (''Gavialis gangeticus'') population with an unmanned aerial vehicle (UAV) |journal=Journal of Unmanned Vehicle Systems |volume=6 |issue=2 |pages=71–82 |doi=10.1139/juvs-2017-0026 |doi-access=free|hdl=1807/87439 |hdl-access=free }}</ref>

In India, gharial populations are present in the:
*[[Ramganga]] River in Corbett National Park, where five gharials were recorded in 1974. Captive-bred gharials were released since the late 1970s. The population is breeding since 2008, and increased to about 42 adults by 2013.<ref>{{cite journal |author=Chowfin, S. |year=2010 |title=Crocodilian and freshwater research and conservation project, Uttarakhand, India |journal=Crocodile Specialist Group Newsletter |volume=29 |issue=3 |page=19 |url=http://www.iucncsg.org/365_docs/attachments/protarea/CSG%20-4575e7bc.pdf}}</ref><ref>{{cite book |author1=Chowfin, S. M. |author2=Leslie, A. J. |name-list-style=amp |year=2013 |chapter=A preliminary investigation into nesting and nest predation of the critically endangered, gharial (''Gavialis gangeticus'') at Boksar in Corbett Tiger Reserve, Uttarakhand, India |pages=26−28 |title=World Crocodile Conference. Proceedings of the 22nd Working Meeting of the IUCN-SSC Crocodile Specialist Group |location=Gland |publisher=IUCN Crocodile Specialist Group |chapter-url=http://www.hwctf.org/Proceedings%20of%20the%2022nd%20Working%20Meeting%20of%20the%20IUCN-SSC%20Crocodile%20Specialist%20Group.pdf#page=27}}</ref> Most of them congregate along an {{cvt|8|km}} long stretch of the Kalagarh Reservoir's shoreline. Surveys in 2015 revealed a population of 90 gharials, including 59 breeding adults.<ref>{{cite book |author1=Chowfin, S. M. |author2=Leslie, A. J. |name-list-style=amp |year=2016 |chapter=The Gharial (''Gavialis gangeticus'') in Corbett Tiger Reserve |title=Crocodiles. Proceedings of the 24th Working Meeting of the Crocodile Specialist Group in Skukuza, South Africa, 23–26 May 2016 |editor=Crocodile Specialist Group |publisher=IUCN |location=Gland |pages=120–124 |chapter-url=http://www.iucncsg.org/365_docs/attachments/protarea/cbb669b854f5d9b31438d0eca189915e.pdf#page=121}}</ref>
*Ganges, where 494 gharials were released between 2009 and 2012 in [[Hastinapur Wildlife Sanctuary]].<ref>{{cite book |author1=Yadav, S. K. |author2=Nawab, A. |author3=Afifullah Khan, A. |name-list-style=amp |year=2013 |chapter=Conserving the Critically Endangered Gharial ''Gavialis gangeticus'' in Hastinapur Wildlife Sanctuary, Uttar Pradesh: Promoting better coexistence for conservation |pages=78−82 |title=World Crocodile Conference. Proceedings of the 22nd Working Meeting of the IUCN-SSC Crocodile Specialist Group |publisher=Gland: IUCN Crocodile Specialist Group |chapter-url=http://www.hwctf.org/Proceedings%20of%20the%2022nd%20Working%20Meeting%20of%20the%20IUCN-SSC%20Crocodile%20Specialist%20Group.pdf#page=79}}</ref><ref>{{cite web |title=An endangered apex predator returns to the Ganga River |url=https://www.worldwildlife.org/magazine/issues/winter-2021/articles/an-endangered-apex-predator-returns-to-the-ganga-river |website=World Wildlife Fund |access-date=15 August 2023 |language=en}}</ref>
*Girwa River in [[Katarniaghat Wildlife Sanctuary]] where the small breeding population was reinforced with captive reared gharials since 1979.<ref name=Rao1992>{{cite journal |author1=Rao, R. J. |author2=Choudhury, B. C. |name-list-style=amp |year=1992 |title=Sympatric distribution of gharial and mugger in India |journal=Journal of the Bombay Natural History Society |volume=89 |pages=312–315 |url=https://archive.org/details/journalofbombay891992bomb/page/312}}</ref> A total of 909 gharials were released until 2006, but only 16 nesting females were recorded in the same year.<ref name=iucn/> In December 2008, 105 individuals were counted, including 35 adults. In spring 2009, 27 nests were detected in seven sites.<ref>{{cite journal |author1=Das, A. |author2=Basu, D. |author3=Converse, L. |author4=Choudhury, S. C. |name-list-style=amp |year=2012 |title=Herpetofauna of Katerniaghat Wildlife Sanctuary, Uttar Pradesh, India |journal=Journal of Threatened Taxa |volume=4 |issue=5 |pages=2553–2568 |doi=10.11609/JoTT.o2587.2553-68|doi-access=free }}</ref> The number of nest sites decreased from seven in 2017 to two in 2019, possibly due to the upgrowth of woody vegetation and reduced river flow near sandbanks.<ref>{{cite journal |author1=Vashistha, G. |name-list-style=amp |author2=Mungi, N.A. |author3=Lang, J.W. |author4=Ranjan, V. |author5=Dhakate, P.M. |author6=Khudsar, F.A. |author7=Kothamasi, D. |title=Gharial nesting in a reservoir is limited by reduced river flow and by increased bank vegetation |journal=Scientific Reports |year=2021 |volume=11 |issue=1 |page=4805  |doi=10.1038/s41598-021-84143-7 |pmid=33637782 |pmc=7910305 |bibcode=2021NatSR..11.4805V |doi-access=free}}</ref> 
*[[Gandaki River#India|Gandaki River]] downstream the Triveni barrage west of [[Valmiki Tiger Reserve]] and adjacent to [[Sohagi Barwa Sanctuary]].<ref>{{cite book |author=Choudhary, S. K. |year=2010 |title=Multi-species Survey in River Gandak, Bihar with focus on Gharial and Ganges River Dolphin |publisher=T. M. Bhagalpur University |location=Bhagalpur |url=https://www.academia.edu/10105543}}</ref> The population increased from 15 gharials in 2010 to 54 individuals recorded in March 2015 on a stretch of {{cvt|320|km}}. 35 of these gharials were wild-born.<ref>{{cite book |year=2016 |title=Crocodiles. Proceedings of the 24th Working Meeting of the Crocodile Specialist Group in Skukuza, South Africa, 23-26 May 2016 |editor=Crocodile Specialist Group |publisher=IUCN |location=Gland |author1=Choudhury, B. C. |author2=Behera, S. K. |author3=Sinha, S. K. |author4=Chandrashekar, S. |name-list-style=amp |chapter=Restocking, Monitoring, Population Status, New Breeding Record and Conservation Actions for Gharial in the Gandak River, Bihar, India |page=124 |chapter-url=http://www.iucncsg.org/365_docs/attachments/protarea/cbb669b854f5d9b31438d0eca189915e.pdf#page=125}}</ref> The population in the {{cvt|320|km}} long river section from the Triveni barrage to the confluence with the Ganges was estimated at 196 adults, 161 juveniles, 140 sub-adults and 37 yearlings between post-monsoon season of 2019 and pre-monsoon 2021.<ref>{{cite journal |author1=Panda, A.K. |name-list-style=amp |author2=Katdare, S. |author3=Gawan, S. |author4=Sharma, S.P. |author5=Badola, R. |author6=Hussain, S.A. |year=2023 |title=Population status and factors influencing the distribution of Critically Endangered gharial (''Gavialis gangeticus'') in a regulated unprotected river system in India |journal=Global Ecology and Conservation |volume=46 |article-number=e02547 |doi=10.1016/j.gecco.2023.e02547 |bibcode=2023GEcoC..4602547P |doi-access=free}}</ref>
*[[Chambal River]] in [[National Chambal Sanctuary]] where 107 gharials were recorded in 1974. Captive-bred gharials were released since 1979, and the population increased to 1,095 gharials in 1992.<ref name=Hussain1999>{{cite journal |author=Hussain, S. A. |year=1999 |title=Reproductive success, hatchling survival and rate of increase of gharial ''Gavialis gangeticus'' in National Chambal Sanctuary, India |journal=Biological Conservation |volume=87 |issue=2 |pages=261−268 |doi=10.1016/S0006-3207(98)00065-2 |bibcode=1999BCons..87..261A}}</ref> Between December 2007 and March 2008, 111 gharials were found dead.<ref name=Nawab_al2013>{{Cite book |publisher=Springer International Publishing |year=2013 |isbn=978-3-319-01344-2 |pages=221–229 |title=Faunal Heritage of Rajasthan, India |doi=10.1007/978-3-319-01345-9_9 |first1=A. |last1=Nawab |first2=D. J. |last2=Basu |first3=S. K. |last3=Yadav |first4=P. |last4=Gautam |chapter=Impact of Mass Mortility of Gharial Gavialis gangeticus (Gmelin, 1789) on its Conservation in the Chambal River in Rajasthan |name-list-style=amp |editor-first=B. K. |editor-last=Sharma |editor-first2=S. |editor-last2=Kulshreshtha |editor-first3=A. R. |editor-last3=Rahmani}}</ref> A total of 948 gharials were counted during surveys in 2013 along the protected river stretch of {{cvt|414|km}}.<ref>{{cite book |author1=Rao, R. J. |author2=Tagor, S. |author3=Singh, H. |author4=Dasgupta, N. |name-list-style=amp |year=2013 |chapter=Monitoring of Gharial (''Gavialis gangeticus'') and its habitat in the National Chambal Sanctuary, India |pages=66−73 |title=World Crocodile Conference. Proceedings of the 22nd Working Meeting of the IUCN-SSC Crocodile Specialist Group |location=Gland |publisher=IUCN Crocodile Specialist Group |chapter-url=http://www.hwctf.org/Proceedings%20of%20the%2022nd%20Working%20Meeting%20of%20the%20IUCN-SSC%20Crocodile%20Specialist%20Group.pdf#page=67}}</ref> In 2017, this population was estimated at 617–761 mature individuals and more than 1250 individuals by two different survey teams; 411 nests were found.<ref name=Khandal_al2017>{{cite journal |author1=Khandal, D. |author2=Sahu, Y. K. |author3=Dhakad, M. |author4=Shukla, A. |author5=Katdare, S. |author6=Lang, J. W. |name-list-style=amp |year=2017 |title=Gharial and Mugger in upstream tributaries of the Chambal River, north India |journal=Crocodile Specialist Group Newsletter |volume=36 |issue=4 |pages=11–16 |url=http://www.iucncsg.org/365_docs/attachments/protarea/0add0eef2e93114c16d6db73f1a9aab3.pdf}}</ref>
*[[Parbati River (Madhya Pradesh)|Parbati River]], a tributary of the Chambal River, where gharials started using a few sand banks since about 2015; 29 gharials were observed in 2016, and 251 hatchlings were counted at two nesting sites in 2017.<ref name=Khandal_al2017/>
*[[Yamuna]] River where eight young gharials were detected in autumn 2012 near the confluence of the [[Ken River|Ken]] and Yamuna Rivers. They were probably offspring of the breeding population in the Chambal River and had drifted downriver during monsoon floods.<ref>{{cite journal |author=Nair, T. |year=2012 |title=Gharial hatchlings in the Yamuna |journal=Crocodile Specialist Group Newsletter |volume=32 |issue=4 |page=17 |url=http://www.iucncsg.org/365_docs/attachments/protarea/News-153f3fd2.pdf#page=17}}</ref>
*[[Son River]] where 164 captive-reared gharials were released between 1981 and 2011.<ref name=Nair2013>{{cite book |author1=Nair, T. |author2=Katdare, S. |name-list-style=amp |year=2013 |chapter=Dry-season assessment of gharials (''Gavialis gangeticus'') in the Betwa, Ken and Son Rivers, India |pages=53−65 |title=World Crocodile Conference. Proceedings of the 22nd Working Meeting of the IUCN-SSC Crocodile Specialist Group |publisher=Gland: IUCN Crocodile Specialist Group |chapter-url=http://www.hwctf.org/Proceedings%20of%20the%2022nd%20Working%20Meeting%20of%20the%20IUCN-SSC%20Crocodile%20Specialist%20Group.pdf#page=54}}</ref>
*Koshi River in Bihar, where two gharials were sighted basking in late January 2019 during a survey targeting [[South Asian River Dolphin]]s (''Platanista gangetica'') on a stretch of about {{cvt|175|km}}. This is the first record of wild gharials in the river since the 1970s.<ref>{{cite journal |author1=Nair, T. |author2=Dey, S. |author3=Gupta, S. P. |name-list-style=amp |year=2019 |title=Relicts in the River: Short Survey for Gharials (''Gavialis gangeticus'') in the Kosi River, India |journal=Crocodile Specialist Group Newsletter |volume=38 |issue=4 |pages=11–14 |url=http://www.iucncsg.org/365_docs/attachments/protarea/088e46b7001f85854cb7d30b1c90b743.pdf#page=11}}</ref>
*[[Mahanadi River]] in [[Odisha]]'s Satkosia Gorge Sanctuary where about 700 gharials were released between 1977 and the early 1990s.<ref name=Rao1992/><ref>{{cite journal |author=Bustard, H. R. |year=1983 |title=Movement of wild Gharial, ''Gavialis gangeticus'' (Gmelin) in the River Mahanadi, Orissa (India) |journal=British Journal of Herpetology |pages=287–291 |volume=6}}</ref> During a 1.5 year long survey in 2005–2006, only one male and one female gharial were detected moving together and sharing sand banks in the river.<ref>{{cite journal |author1=Mohanty, B. |author2=Nayak, S. K. |author3=Panda, B. |author4=Mitra, A. |author5=Pattanaik, S. K. |name-list-style=amp |year=2010 |title=Gharial (''Gavialis gangeticus'') in the Mahanadi River system of Orissa, India: On the brink of extinction |journal=E-planet |volume=8 |issue=8 |pages=49–52}}</ref>
Between 1979 and 1993, fewer than 20 individuals were sighted in the upper reaches of the Brahmaputra River between [[Kaziranga National Park]] and [[Dibru-Saikhowa National Park]]. This population had declined due to commercial fishing, [[poaching]], encroachment by local people in gharial breeding grounds and [[siltation]] of river beds following [[deforestation]]. In 1998, it was not considered to be viable.<ref>{{cite journal |author1=Choudhury, A. U. |year=1998 |title=Status of the gharial ''Gavialis gangeticus'' in the main Brahmaputra river |journal=Journal of the Bombay Natural History Society |volume=95 |issue=1 |pages=118–120 |url=https://archive.org/details/journalofbombay941997bomb/page/162}}</ref> About 30 gharials were observed in small lakes and tributaries of the Brahmaputra River in Assam between 2004 and 2007.<ref>{{cite book |author1=Saikia, B. P. |year=2010 |chapter=Indian Gharial (''Gavialis gangeticus''): Status, ecology and conservation |title=Rare Animals of India |editor=Singaravelan, N. |publisher=Bentham Science Publishers |location=Sharjah |pages=76–100 |isbn=978-1-60805-485-5 |chapter-url=https://books.google.com/books?id=BUPcAwAAQBAJ&pg=PA76}}</ref>

In Bangladesh, gharials were recorded in [[Padma River|Padma]], [[Jamuna River (Bangladesh)|Jamuna]], [[Mahananda River|Mahananda]] and Brahmaputra rivers between 2000 and 2015.<ref>{{cite book |author1=Hasan, K. |author2=Alam, S. |name-list-style=amp |year=2016 |title=Gharials of Bangladesh |publisher=IUCN Bangladesh Country Office |location=Dhaka |chapter=Chapter 3: Findings |pages=29–65 |chapter-url=https://www.researchgate.net/publication/326981894}}</ref>

==Behaviour and ecology==
{{multiple image |direction=vertical |image1=Co-existence_of_Rarities.jpg |image2=Mother_and_Chilld.jpg |caption2=Gharials in National Chambal Sanctuary}}
The gharial is the most thoroughly aquatic crocodilian.<ref name=Whitaker1982/> It leaves the water only for [[Sunning (behaviour)|basking]] on riverbanks.<ref name=Bustard1977/> Being cold-blooded, it seeks to cool down during hot times and to warm up when ambient temperature is cool.<ref>{{cite book |author=Lang, J. W. |year=1987 |chapter=Crocodilian behaviour: implications for management |pages=273−294 |title=Wildlife Management: Crocodiles and Alligators |editor1=Webb, G. J. W. |editor2=Manolis, S. C. |editor3=Whitehead, P. J. |publisher=Surrey Beatty and Sons |location=Sydney}}</ref> Gharials bask daily in the cold season, foremost in the mornings, and prefer sandy and moist beaches. They change their basking pattern with increasing daily temperatures; they start basking earlier in the mornings, move back into the river when it is hot, and return to the beach later in the afternoon. Groups comprising an adult male, several females and subadults have been observed to bask together. Adult males dominate groups and tolerate immature males.<ref name=Whitaker1982/>
Large groups of young, subadult and adult gharials form in December and January to bask. Adult males and females associate by mid February.<ref name=Lang2013>{{cite book |author1=Lang, J. W. |author2=Kumar, P. |name-list-style=amp |year=2013 |chapter=Behavioral ecology of Gharial on the Chambal River, India |pages=42−52 |title=World Crocodile Conference. Proceedings of the 22nd Working Meeting of the IUCN-SSC Crocodile Specialist Group |publisher=Gland: IUCN Crocodile Specialist Group |chapter-url=http://www.hwctf.org/Proceedings%20of%20the%2022nd%20Working%20Meeting%20of%20the%20IUCN-SSC%20Crocodile%20Specialist%20Group.pdf#page=43}}</ref>

The gharial shares riverine habitat with the [[mugger crocodile]] (''Crocodylus palustris'') in parts of its range. They use the same nesting grounds, but differ in the selection of basking sites.<ref>{{cite journal |author1=Rao, R. J. |author2=Choudhury, B. C. |name-list-style=amp |year=1992 |title=Sympatric distribution of Gharial ''Gavialis gangeticus'' and Mugger ''Crocodylus palustris'' in India |journal=Journal of the Bombay Natural History Society |volume= 89 |issue=3 |pages=313–314 |url=https://archive.org/details/journalofbombay891992bomb/page/312}}</ref>
The gharial basks close to water on shallow, sandy beaches and lays eggs only in sandy soil near water. The mugger crocodile also basks on sandy beaches, but unlike the gharial climbs steep embankments and rocks, and moves farther away from beaches for both basking and nest building.<ref name=Choudhary_al2018>{{cite journal |author1=Choudhary, S. |author2=Choudhury, B. C. |author3=Gopi, G. V. |name-list-style=amp |year=2018 |title=Spatio-temporal partitioning between two sympatric crocodilians (''Gavialis gangeticus'' & ''Crocodylus palustris'') in Katarniaghat Wildlife Sanctuary, India |journal=Aquatic Conservation: Marine and Freshwater Ecosystems |volume=28 |issue=5 |pages=1067–1076 |doi=10.1002/aqc.2911 |bibcode=2018ACMFE..28.1067C |s2cid=91126092 |url=https://www.researchgate.net/publication/325692895}}</ref> It also preys on fish, but has a broader prey base than the gharial including [[snake]]s, [[turtle]]s, [[bird]]s, [[mammal]]s and dead animals.<ref>{{cite book |author=Whitaker, R. & Whitaker, Z. |year=1989 |chapter=Ecology of the mugger crocodile |title=Crocodiles, their ecology, management, and conservation |location=Gland |publisher= IUCN Crocodile Specialist Group |pages=276–296 |chapter-url=https://portals.iucn.org/library/sites/library/files/documents/NS-1989-001.pdf}}</ref>

===Feeding ecology===
The gharial is well adapted to hunting fish underwater because of its sharp interlocking teeth and long narrow snout, which meets little resistance in the water. It does not chew its prey, but swallows it whole. Juvenile gharials were observed to jerk their heads back to manoeuvre fish into their gullets, sliding them in head first. Young gharials feed on [[insects]], [[tadpole]]s, small fish and [[frog]]s. Adults also feed on small [[crustacean]]s. Remains of [[Indian softshell turtle]] (''Nilssonia gangetica'') were also found in gharial stomachs. Gharials tear apart large fish and pick up and swallow stones as [[gastrolith]]s, probably to aid digestion or regulate buoyancy. Some gharial stomachs also contained jewellery.<ref name=Whitaker1982/>
Stones weighing about {{cvt|10|lbs|order=flip}} were found in a gharial's stomach that was shot in the [[Sharda River]] in 1910.<ref>{{cite journal |author=Forsyth, H. W. |year=1914 |title=The food of Crocodiles |journal=Journal of the Bombay Natural History Society |volume=23 |issue=1 |pages=228–229 |url=https://archive.org/details/journalofbombayn20191011bomb/page/228/mode/2up}}</ref>

===Reproduction===
Females mature at a body length of around {{cvt|2.6|m|ftin|sigfig=1}}.<ref name=Whitaker1982/> Captive females breed at a body length of {{cvt|3|m|ftin|sigfig=1}}.<ref>{{cite journal |author=Bustard, H. R. |author2=Maharana, S. |name-list-style=amp |year=1983 |title=Size at first breeding in the Gharial [''Gavialis gangeticus'' (Gmelin)] (Reptilia, Crocodilia) in captivity |journal=Journal of the Bombay Natural History Society |volume=79 |issue=1 |pages=206−207 |url=https://archive.org/details/journalofbombay791982bomb/page/206}}</ref> Male gharials mature at 15–18 years of age, when they reach a body length of around {{cvt|4|m|ft}} and once the ghara is developed.<ref name=Whitaker07/> The ghara is apparently used to indicate sexual maturity, as a sound resonator when bubbling underwater or for other sexual behaviours.<ref>{{cite journal |author1=Martin, B. G. H. |name-list-style=amp |author2=Bellairs, A. d'A. |author-link2=:fr:Angus d'Albini Bellairs |year=1977 |title=The narial excrescence and pterygoid bulla of the gharial, ''Gavialis gangeticus'' (Crocodilia) |journal=Journal of Zoology |volume=182 |issue=4|pages=541–558 |doi=10.1111/j.1469-7998.1977.tb04169.x}}</ref>

Courting and [[mating]] start by mid-February at the end of the cold season. In the dry season, reproductive females observed in the Chambal River routinely move {{cvt|80|-|120|km}} and join female breeding groups to dig nests together.<ref name=Lang2013/> They select sites in riverside sand or silt banks located between  {{cvt|2.5|and|14.5|m|ftin}} away from the water and above a water level of {{cvt|1|to|3.5|m|ftin}}. These nests are {{cvt|20-55|cm|ftin}} deep with a diameter of about {{cvt|50-60|cm|ftin}}. Females have been observed digging "trial nests".<ref>{{cite journal |date=2024 |title=Nesting of the Critically Endangered gharial ''Gavialis gangeticus'' in Bardia National Park, Nepal |author1=Bashyal, A. |author2=Shrestha, N. |author3=Thapa, R. |author4=Shrestha, S. |author5=Sanjel, M. |author6=Densmore, L. D. |author7=Khadka, B. |journal=Oryx |volume=58 |issue=3 |pages=340–343 |doi=10.1017/S0030605324000103 |doi-access=free |name-list-style=amp|hdl=2346/98133 |hdl-access=free }}</ref> Between end of March and early April, they lay 20–95 [[Egg (biology)|egg]]s.<ref name=Whitaker1982/> A record [[Clutch (eggs)|clutch]] with 97 eggs was found in Katarniaghat Wildlife Sanctuary.<ref>{{cite journal |author=Bustard, H. R. |author2=Basu, S. |name-list-style=amp |year=1983 |title=A record Gharial clutch |journal=Journal of the Bombay Natural History Society |volume=79 |issue=1 |pages=207−208 |url=https://archive.org/details/journalofbombay791982bomb/page/207}}</ref>
The eggs are the largest of all crocodilians and weigh an average of {{cvt|160|g}}.<ref name=Whitaker07/> Each egg is {{cvt|85-90|mm}} long and {{cvt|65-70|mm}} wide.<ref name=Smith1931>{{cite book |author=Smith, M. A. |author-link=Malcolm Arthur Smith |year=1931 |title=The Fauna of British India, Including Ceylon and Burma. Reptilia and Amphibia |volume=((I. Loricata, Testudines)) |location=London |publisher=Secretary of State for India in Council |chapter=''Gavialis'' |pages=37–40 |chapter-url=https://archive.org/details/FBISmithReptiles1/page/n63}}</ref> After 71 to 93 days of [[egg incubation|incubation]], young gharials hatch in July just before the onset of the [[monsoon]]. Their sex is most likely [[temperature-dependent sex determination|determined by temperature]], like in most reptiles.<ref name=Whitaker1982/> Females dig up the [[hatchling]]s in response to hatching chirps, but do not assist them to reach the water.<ref name=Whitaker07/> They stay at nesting sites until monsoon floods arrive and return after monsoon.<ref name=Lang2013/>

Captive male gharials observed in the 1980s did not participate in guarding nests. A captive male gharial was observed to show an interest in hatchlings and was allowed by the female to carry hatchlings on his back.<ref>{{cite journal |author=Bustard, H. R. |year=1982 |title=Behaviour of the male Gharial during the nesting and post-hatching period |journal=Journal of the Bombay Natural History Society |volume=79 |issue=3 |pages=677–680 |url=https://archive.org/details/journalofbombay791982bomb/page/530}}</ref>
In the Chambal River, females were observed to stay close to nest sites and guard young gharials until the shoreline was flooded. [[VHF]] [[Radio telemetry|radio tracking]] of a junior male gharial revealed that he was the dominant male guarding nests at a communal nesting site for two years.<ref>{{cite book |year=2016 |title=Crocodiles. Proceedings of the 24th Working Meeting of the Crocodile Specialist Group Skukuza, South Africa, 23-26 May 2016 |editor=Crocodile Specialist Group |publisher=IUCN |location=Gland |author1=Lang, J. W. |author2=Kumar, P. |name-list-style=amp |chapter=Chambal Gharial Ecology Project{{Snd}} 2016 Update |pages=136–148 |chapter-url=http://www.iucncsg.org/365_docs/attachments/protarea/cbb669b854f5d9b31438d0eca189915e.pdf#page=137}}</ref>
The availability of open riverbanks at potential nesting sites is crucial for reproductive success.<ref>{{cite journal |author1=Vashistha, G. |author2=Mungi, N.A. |author3=Lang, J.W. |author4=Ranjan, V.  |author5=Dhakate, P.M. |author6=Khudsar, F.A. |author7=Kothamasi, D. |name-list-style=amp |year=2021 |title=Gharial nesting in a reservoir is limited by reduced river flow and by increased bank vegetation |journal=Scientific Reports |volume=11 |issue=1 |page=4805 |doi=10.1038/s41598-021-84143-7 |pmid=33637782|pmc=7910305 |bibcode=2021NatSR..11.4805V }}</ref>

===Development===
[[File:Baby Gharial.jpg|thumb|Young gharial in the breeding center at [[Kukrail Reserve Forest]]]]
Hatchlings range from {{cvt|34-39.2|cm}} in body length with a weight of {{cvt|82-130|g}}. In two years, they grow to a length of {{cvt|80-116|cm}} and of {{cvt|130-158|cm}} in three years.<ref name=Whitaker1982/>
Gharials hatched and raised in Nepal's Gharial Conservation and Breeding Center measured {{cvt|140-167|cm}} and weighed {{cvt|5.6-10.5|kg}} at the age of 45 months in April 2013. They consumed up to {{cvt|3.5|kg}} of fish per individual and month. By the age of 75 months, they had gained {{cvt|5.9-19.5|kg}} in weight and grown {{cvt|29-62|cm}} reaching body lengths of {{cvt|169-229|cm}}.<ref>{{cite journal |author1=Khadka, B. B. |author2=Bashyal, A. |name-list-style=amp |year=2019 |title=Growth rate of captive Gharials ''Gavialis gangeticus'' (Gmelin, 1789) (Reptilia: Crocodylia: Gavialidae) in Chitwan National Park, Nepal |journal=Journal of Threatened Taxa |volume=11 |issue=15 |pages=14998–15003 |doi=10.11609/jott.5491.11.15.14998-15003 |doi-access=free}}</ref>

Young gharials in their first year of age hide and forage in shallow water, preferably in sites that are surrounded by debris of fallen trees.<ref name=Whitaker1982/> A study along a {{cvt|425|km}} stretch of the Chambal River revealed that juvenile gharials up to a body length of {{cvt|120|cm|ftin|sigfig=1}} prefer basking sites where the mid river water is {{cvt|1-3|m|ftin|sigfig=1}} deep. As their body size increases, they move to sites with deeper water. Subadult and adult gharials above a body length of {{cvt|180|cm|ftin|sigfig=1}} prefer sites where the water is deeper than {{cvt|4|m|ftin|sigfig=1}}.<ref>{{cite journal |author=Hussain, S. A. |title=Basking site and water depth selection by Gharial ''Gavialis gangeticus'' Gmelin 1789 (Crocodylia, Reptilia) in National Chambal Sanctuary, India and its implication for river conservation |journal=Aquatic Conservation: Marine and Freshwater Ecosystems |year=2009 |volume=19 |issue=2 |pages=127–133 |doi=10.1002/aqc.960|bibcode=2009ACMFE..19..127H}}</ref>

Young gharials move forward by pushing the diagonally opposite legs synchronously. At a young age, they can also gallop but do so only in emergency situations. When they reach a length of about {{cvt|75|cm}} and a weight of about {{cvt|1.5|kg|lb}} at the age of 8–9 months, they change to an adult pattern of locomotion of pushing forward with hind and front legs simultaneously. Adults do not have the ability to walk on land in the semi-upright stance as other crocodilians. When basking on the beach, they often turn round so as to face the water.<ref name=Bustard1977/>

==Threats==
The gharial population is estimated to have declined from 5,000–10,000 individuals in 1946 to fewer than 250 individuals in 2006, a decline of 96–98% within three generations. Gharials were killed by fishermen, hunted for skins, trophies and [[indigenous medicine]], and their eggs collected for consumption. The remaining individuals form several fragmented subpopulations. Hunting is no longer considered a significant threat. However, the wild population declined from an estimated 436 adult gharials in 1997 to fewer than 250 mature individuals in 2006. One reason for this decline is the increased use of [[gill net]]s for fishing in gharial habitat. The other major reason is the loss of riverine habitat as dams, [[barrage (dam)|barrage]]s, irrigation canals and artificial [[wikt:embankment|embankment]]s were built; [[siltation]] and [[sand-mining]] changed river courses; and land near rivers is used for agriculture and grazing by livestock.<ref name=iucn/>

When 111 dead gharials were found in the Chambal River between December 2007 and March 2008, it was initially suspected that they had died either because of toxicants or the illegal use of fish nets, in which they became entrapped in and subsequently drowned.<ref name=Nawab_al2013/> Later post mortem [[Pathology|pathological]] testing of tissue samples revealed high levels of [[Heavy metal (chemistry)|heavy metal]]s such as [[lead]] and [[cadmium]], which together with stomach [[ulcer]]s and [[protozoa]]n [[parasite]]s reported in most [[necropsies]] were thought to have caused their deaths.<ref>{{cite journal |author1=Whitaker, R. |author2=Basu, D. |author3=Huchzermeyer, F. |name-list-style=amp |year=2008 |title=Update on gharial mass mortality in National Chambal Sanctuary |journal=Crocodile Specialist Group Newsletter |volume=27 |issue=1 |pages=4–8 |url=http://www.iucncsg.org/365_docs/attachments/protarea/CSG%20-8d303c03.pdf}}</ref> Water pumps used for pumping water out of the Chambal River have proven to negatively impact the gharial population.<ref>{{cite journal |author=Katdare, S. |year=2011 |title=Gharial (''Gavialis gangeticus'') populations and human influences on habitat on the River Chambal, India |journal=Aquatic Conservation |volume=21 |issue=4 |pages=364–371 |doi=10.1002/aqc.1195|bibcode=2011ACMFE..21..364K }}</ref>

Threats in unprotected stretches of the Karnali River include [[quarry]]ing for [[boulder]]s, sand mining and unlicensed fishing.<ref name=Bashyal_al2021/>

==Conservation==
The gharial is listed on [[CITES Appendix I]].<ref name=iucn/> In India, it is protected under the [[Wildlife Protection Act of 1972]].<ref name=Whitaker07/> In Nepal, it is fully protected under the National Parks and Wildlife Conservation Act of 1973.<ref name="maskey94"/>

=== Reintroduction programmes ===
[[File:Gharial Crocodiles - Conservation Breeding Center - Kasara - Chitwan National Park - Nepal - 01 (13907486606).jpg|thumb|Gharials in the Gharial Conservation and Breeding Center at [[Chitwan National Park]]]]
Since the late 1970s, the gharial conservation approach has been focused on [[reintroduction]]. Rivers in protected areas in India and Nepal used to be restocked with captive-bred juvenile gharials. Gharial eggs were incubated, hatched and juvenile gharials raised for two to three years and released when about one metre in length.<ref name=iucn/>

In 1975, the Indian Crocodile Conservation Project was set up under the auspices of the [[Government of India]], initially in Odisha's Satkosia Gorge Sanctuary. It was implemented with financial aid of the [[United Nations Development Fund]] and the [[Food and Agriculture Organization]]. The country's first gharial breeding center was built in [[Nandankanan Zoological Park]]. A male gharial was flown in from [[Frankfurt Zoological Garden]] to become one of the founding animals of the breeding program. In subsequent years, several protected areas were established.<ref>{{cite journal |last1=Bustard |first1=H. R. |year=1999 |title=Indian Crocodile Conservation Project |journal=Envis Wildlife and Protected Areas |volume=2 |issue=1 |pages=5–9 |url=https://archive.org/details/IndianCrocodilians/page/n9}}</ref> In 1976, two breeding centres were established in Uttar Pradesh, one in [[Kukrail Reserve Forest]] and one in Katarniaghat Wildlife Sanctuary, with facilities to hatch and raise up to 800 gharials each year for release in rivers.<ref>{{cite journal |author1=Singh, A. |author2=Singh, R. L. |author3=Basu, D. |name-list-style=amp |year=1999 |title=Conservation Status of the Gharial in Uttar Pradesh |journal=Envis Wildlife and Protected Areas |volume=2 |issue=1 |pages=91–94 |url=https://archive.org/details/IndianCrocodilians/page/n91/mode/2up}}</ref>
Between 1975 and 1982, sixteen crocodile rehabilitation centers and five crocodile sanctuaries were established in the country. Gharial eggs were initially purchased from Nepal. In 1991, the Ministry of Environment and Forests withdrew funds for the captive-breeding and egg-collection programs, arguing that the project had served its purpose. In 1997–1998, over 1,200 gharials and over 75 nests were located in the National Chambal Sanctuary, but no surveys were carried out between 1999 and 2003. Gharial eggs collected from wild and captive-breeding nests amounted to 12,000 until 2004. Eggs were incubated, and hatchlings were reared to a length of about one meter or more.<ref name=Whitaker07/>
More than 5,000 gharials were released into Indian rivers between the early 1980s and 2006.<ref>{{cite journal |author=Stevenson, C. J. |year=2015 |title=Conservation of the Indian Gharial ''Gavialis gangeticus'': successes and failures |journal=International Zoo Yearbook |volume=49 |issue=1 |pages=150–161 |doi=10.1111/izy.12066}}</ref> Despite the release of 142 gharials between 1982 and 2007 into the [[Ken River]], only one adult female gharial was observed in the river in spring 2013, indicating that most of the released gharials had not reproduced.<ref name=Nair2013/>
Juvenile gharials have also been released into the [[Beas River]] in [[Punjab, India]].<ref name=iucn/>

In Nepal, wild eggs collected along rivers have been incubated in the Gharial Conservation and Breeding Center in [[Chitwan National Park]] since 1978. The first batch of 50 gharials was released in spring 1981 into the Narayani River. In subsequent years, gharials were also released into five other rivers in the country.<ref name="maskey94"/> In 2016, this center was overcrowded with more than 600 gharials aged between 5 and 12 years, and many were too old to be released.<ref name=Lang2017>{{cite journal |author=Lang, J. W. |year=2017 |title=Doing the Needful in Nepal: Priorities of Gharial Conservation |journal=Crocodile Specialist Group Newsletter |volume=36 |issue=2 |pages=9–12 |url=http://www.iucncsg.org/365_docs/attachments/protarea/f6c68866824331a45008304911496a1d.pdf}}</ref>
Between 1981 and 2018, a total of 1,365 gharials were released in the Rapti–Narayani river system.<ref>{{cite journal |author=Khadka, B. B. |year=2018 |title=119 Juvenile Gharials released into the Rapti River, Chitwan National Park, Nepal |journal=Crocodile Specialist Group Newsletter |volume=37 |issue=1 |page=12−13 |url=http://www.iucncsg.org/365_docs/attachments/protarea/9165a6d4d4d38607adc3b1e8b9e93c5e.pdf}}</ref>
Reintroducing gharials helped to maintain this population, but the survival rate of released gharials was rather low. Of 36 marked gharials released in the spring seasons of 2002 and 2003 into the Rapti–Narayani rivers, only 14 were found alive in spring 2004.<ref name=Ballouard_al2010/> This reintroduction programme has been criticised in 2017 as not being comprehensive and coordinated, as often too old and unsexed gharials were released at disturbed localities during unfavourable cold months and without assessing the efficiency of these releases.<ref name=Lang2017/>
It has been suggested to instead leave wild nests in place, increase protection of nesting and basking sites and monitor the movement of gharials.<ref>{{cite journal |author1=Acharya, K. P. |author2=Khadka, B. K. |author3=Jnawali, S. R. |author4=Malla, S. |author5=Bhattarai, S. |author6=Wikramanayake, E. |author7=Köhl, M. |name-list-style=amp |year=2017 |title=Conservation and population recovery of Gharials (''Gavialis gangeticus'') in Nepal |journal=Herpetologica |volume=73 |issue=2 |pages=129–135 |doi=10.1655/HERPETOLOGICA-D-16-00048.1|s2cid=90546861 }}</ref>

Releasing captive-reared gharials did not contribute significantly to re-establishing viable populations.<ref name=iucn/>
Monitoring of released gharials revealed that the reintroduction programmes did not address multiple factors affecting their survival. These factors include disturbances from diversions of river courses, [[sand mining]], cultivation of riversides, fishing by local people and mortality related to fishing methods like the use of gill nets and [[dynamite]].<ref>{{cite journal |author1=Katdare, S. |author2=Srivathsa, A. |author3=Joshi, A. |author4=Panke, P. |author5=Pande, R. |author6=Khandal, D. |author7=Everard, M. |name-list-style=amp |year=2011 |title=Gharial (''Gavialis gangeticus'') populations and human influences on habitat on the River Chambal, India |journal=Aquatic Conservation: Marine and Freshwater Ecosystems |volume=21 |issue=4 |pages=364–371 |doi=10.1002/aqc.1195 |bibcode=2011ACMFE..21..364K }}</ref><ref>{{cite journal |author1=Nair, T. |name-list-style=amp |author2=Thorbjarnarson, J. B. |author3=Aust, P. |author4=Krishnaswamy, J. |year=2012 |title=Rigorous gharial population estimation in the Chambal: implications for conservation and management of a globally threatened crocodilian |journal=Journal of Applied Ecology |volume=49 |issue=5 |pages=1046–1054 |doi=10.1111/j.1365-2664.2012.02189.x|bibcode=2012JApEc..49.1046N |doi-access=free }}</ref>
In 2017, members of the Crocodile Specialist Group therefore recommended to foster engagement of local communities in gharial conservation programs.<ref>{{cite journal |author=Webb, G. |year=2018 |title=Editorial |journal=Crocodile Specialist Group Newsletter |volume=37 |issue=1 |page=3−4 |url=http://www.iucncsg.org/365_docs/attachments/protarea/9165a6d4d4d38607adc3b1e8b9e93c5e.pdf}}</ref>

In May 2023, sightings of the Gharial were reported in the Punjab region of Pakistan. This marked the first confirmed sighting of the species in Pakistan after a presumed absence of three decades. In response to these sightings, [[WWF-Pakistan]], in collaboration with the other partners, aims to step up [[Gharial conservation in Pakistan|conservation efforts for the Gharial]]. The goal is to ensure that the newly discovered population not only survives but thrives. Pakistan has requested the transfer of hundreds of Gharial crocodiles from Nepal in an effort to reintroduce the species.<ref>{{Cite web|url=https://tribune.com.pk/story/2416863/sighting-of-critically-endangered-gharial-signals-hope-for-species-revival|title=Sighting of extinct Gharial signals hope for species revival|date=May 15, 2023|website=The Express Tribune}}</ref><ref>{{Cite web|url=https://www.wwfpak.org/?379460/Gharials-in-Pakistan--what-we-know-so-far|title=Gharials in Pakistan- what we know so far|website=www.wwfpak.org}}</ref><ref>{{Cite web|url=https://wwf.panda.org/wwf_news/?154242/monitoring-gharial|title=Monitoring and assessment of gharial conservation initiatives|website=wwf.panda.org}}</ref>

=== ''In situ'' projects ===
The riverbanks of Girwa river were cleared from woody vegetation on sand banks and mid-river islands in 2019, and sand was added in 2020 to create an artificial sand bank of about {{cvt|1000|m2}}. This intervention helped to stabilise and optimise the soil temperature at this site. In 2020, the number of gharial nests on this river stretch increased to 36 from 25 in 2018, and the number of unhatched eggs and dead hatchlings decreased significantly.<ref>{{cite journal |author1=Vashistha, G. |name-list-style=amp |author2=Lang, J.W. |author3=Dhakate, P.M. |author4=Kothamasi, D. |year=2021 |title=Sand addition promotes gharial nesting in a regulated river-reservoir habitat |journal=Ecological Solutions and Evidence |volume=2 |issue=2 |article-number=e12068 |doi=10.1002/2688-8319.12068 |doi-access=free|bibcode=2021EcoSE...2E2068V }}</ref>

===In captivity===
[[File:Indian Gharial Crocodile Digon3.JPG|thumb|Gharial in a Florida zoo]]
As of 1999, gharials were also kept in the [[Madras Crocodile Bank Trust]], [[Mysore Zoo]], [[Jaipur Zoo]] and Kukrail Gharial Rehabilitation Centre in India.<ref>{{cite journal |last1=Choudhury |first1=B. C. |year=1999 |title=Crocodile Breeding in Indian Zoos |journal=Envis Wildlife and Protected Areas |volume=2 |issue=1 |pages=100–103 |url=https://archive.org/details/IndianCrocodilians/page/n101}}</ref><!-- [[Thiruvananthapuram Zoo]], [[Indira Gandhi Zoological Park]], [[Jawaharlal Nehru Biological Park]] in [[Bokaro Steel City]], [[Bannerghatta National Park#Zoo|Bannerghatta National Park Zoo]], [[Junagadh Zoo]], [[Chhatbir Zoo]] and Biological Park [[Itanagar]]. Elsewhere in Asia, the [[National Zoological Gardens of Sri Lanka]], [[Singapore Zoo]] and [[Nogeyama Zoo]] in Japan also keep gharials. -->

In Europe, gharials are kept in [[Prague Zoo]] and Protivin Crocodile Zoo in the [[Czech Republic]], and the [[Berlin Zoo]] in Germany.<ref>{{cite book |author=Ziegler, T. |date=2018 |title=Crocodile Specialist Group Steering Committee Meeting, Universidad Nacional del Litoral, Santa Fe, Argentina (6 May 2018) |location=Santa Fe, Argentina |editor=Crocodile Specialist Group |chapter=Europe |pages=Agenda Item: SC. 2.7 |chapter-url=http://www.iucncsg.org/content_images/SantaFe/SC.2.7.%20Europe.pdf}}</ref>
La Ferme aux Crocodiles, a crocodile farm in France, received six juveniles in 2000 from the Gharial Breeding Centre in Nepal.<ref>{{cite web |author=Fougeirol, L. |date=2009 |url=http://www.luc-fougeirol.com/index.php?post%2F2009%2F04%2F11%2FLe-gavial-du-Gange-un-reve |title=''Le gavial du Gange, un rêve''|publisher=www.luc-fougeirol.com |access-date=2017-12-26 |archive-url=https://web.archive.org/web/20110206104136/http://www.luc-fougeirol.com/index.php?post%2F2009%2F04%2F11%2FLe-gavial-du-Gange-un-reve |archive-date=2011-02-06 |language=fr}}</ref>

In the United States, gharials are kept in [[Busch Gardens Tampa]], [[Cleveland Metroparks Zoo]], [[Fort Worth Zoo]], [[Honolulu Zoo]], [[San Diego Zoo]], [[National Zoological Park (United States)|National Zoological Park]], [[San Antonio Zoo and Aquarium]] and [[St. Augustine Alligator Farm Zoological Park]].<ref name=Whitaker07/> [[Bronx Zoo]] and [[Los Angeles Zoo]] received gharials in 2017.<ref>{{cite web |author=Bronx Zoo |url=https://bronxzoo.com/updates/indian-gharials-return-to-the-zoo |title=Indian Gharials return to the Zoo |website=Wildlife Conservation Society |date=2017}}</ref><ref>{{cite web |title=L.A. Zoo Becomes One of Nine Zoos in the Western Hemisphere to House Gharials Flown in from India |date=2017 |website=Los Angeles Zoo and Botanical Gardens |url=https://www.lazoo.org/2017/05/gharials/ |access-date=2018-10-29 |archive-date=2020-10-25 |archive-url=https://web.archive.org/web/20201025085406/https://www.lazoo.org/2017/05/gharials/ }}</ref> In 2023, Fort Worth Zoo announced the birth of four gharials.<ref>{{cite web |author=NBCDFW Staff and Alicia Barrera |url=https://www.nbcdfw.com/news/local/fort-worth-zoo-announces-groundbreaking-births-of-endangered-gharial-crocodiles/3327631/ |title=Fort Worth Zoo announces 'groundbreaking births' of endangered gharial crocodiles |website=NBCDFW |date=2023}}</ref>

==In culture==
[[File:Babur_crossing_the_river_Son.jpg|thumb|upright|A miniature illustration of the ''Baburnama'' showing a gharial, ca. 1598, [[National Museum, New Delhi]]<ref>{{cite book |author=Verma, S. P. |year=2016 |title=The Illustrated Baburnama |location=Oxon |publisher=Routledge |chapter=Part II. Depictions of Natural History, Figure 11 |chapter-url=https://books.google.com/books?id=G4GPCwAAQBAJ&pg=PT491 |page=Figure 11 |isbn=978-1-317-33862-8}}</ref>]]
The earliest known depictions of the gharial date to the [[Indus Valley Civilisation]]. Seals and tablets show gharials with fish in their mouths and surrounded by fish. A tablet shows a deity flanked by a gharial and a fish. These pieces are about 4,000 years old and were found at [[Mohenjo-daro]] and [[Amri, Sindh]].<ref>{{cite book |editor1=Osada, H. |editor2=Endo, H. |year=2011 |title=Linguistics, Archaeology and the Human Past |publisher=Indus Project Research Institute for Humanity and Nature |location=Kyoto, Japan |isbn=978-4-902325-67-6 |author1=Parpola, A. |chapter=Crocodile in the Indus Civilization and later South Asian traditions |pages=1–57 |chapter-url=https://www.harappa.com/sites/default/files/pdf/Parpola_Asko_2011._Crocodile_in_the_Indu.pdf}}</ref>

A gharial is depicted on one of the rock carvings on a pillar of the [[Sanchi]] [[Stupa]], which dates to the 3rd century [[Before Christ|BC]].<ref>{{cite journal |author1=Vyas, R. |year=2018 |title=Gharial Motifs (''Gavialis gangeticus'') at Sanchi Stupa, India |journal=Crocodile Specialist Group Newsletter |volume=37 |issue=4 |page=13 |url=http://www.iucncsg.org/365_docs/attachments/protarea/3ab6597756810d7ab30707a91943b1f3.pdf#page=13}}</ref>
In [[Hindu mythology]], the gharial is the vehicle of the river deity [[Ganga in Hinduism|Gaṅgā]] and of the wind and sea deity [[Varuna]].<ref>{{cite book |author1=Behera, S. K. |author2=Singh, H. |author3=Sagar, V. |name-list-style=amp |year=2014 |chapter=Indicator Species (Gharial and Dolphin) of Riverine Ecosystem: An Exploratory of River Ganga |pages=103–123 |title=Our National River Ganga: Lifeline of Millions |editor=Sanghi, R. |publisher=Springer International Publishing |location=Switzerland |doi=10.1007/978-3-319-00530-0_4 |chapter-url=https://www.researchgate.net/publication/287563244 |isbn=978-3-319-00529-4}}</ref>

In the 16th-century book ''[[Baburnama]]'', Zahir-ud-din Muhammad [[Babur]] accounted of a gharial sighting in the Ghaghara River between [[Ghazipur]] and [[Benares]] in 1526.<ref>{{cite book |author=Babur, Z. M. |translator-last1=Beveridge |translator-first1=A. S |year=1922 |title=Babur-nama |trans-title=The Memoirs of Babur |language=chg |volume=2 |location=London |publisher=Luzac and Co |chapter=Fauna of Hindustan: Aquatic animals |pages=501–503 |chapter-url=https://archive.org/details/baburnamainengli02babuuoft/page/502}}</ref>

In 1915, a British officer observed the traditional method of Kehal fishermen hunting gharials along the Indus. They staked nets about {{convert|60-75|cm|ftin|abbr=on}} below the waterline close by a sandbank and waited hidden for gharials to come out of the river for basking. After some time, they left their hiding places, prompting the gharials to dart off to the river and get entangled in the nets.<ref>{{cite journal |author=Lowis, R. M. |year=1915 |title=Gharial, ''Gavialis gangeticus'', and Porpoise, ''Platanista gangetica'', catching in the Indus |journal=Journal of the Bombay Natural History Society |volume=23 |issue=4 |page=779 |url=https://archive.org/details/journalofbombayn231914bomb/page/779/mode/1up}}</ref>

Local people in Nepal attributed various mystical powers to the ghara of male gharials and killed them to collect their snouts.<ref>{{cite book |author1=Maskey, T. M. |author2=Mishra, H. R. |name-list-style=amp |year=1982 |chapter=Conservation of gharial (''Gavialis gangeticus'') in Nepal |pages=185–196 |title=Wild is beautiful: Introduction to the magnificent, rich and varied fauna and wildlife of Nepal |editor1=Majupuria, T. C. |publisher=Lashkar S. Devi |location=Gwalior, Madhya Pradesh }}</ref> [[Tharu people]] believed that the ghara would repel insects and pests when burnt in a field, and that gharial eggs would be an effective cough medicine and [[aphrodisiac]].<ref name="maskey94"/> Jewellery found in gharial stomachs may have been the reason for the belief of local people that they would eat humans.<ref name=Whitaker1982/>

Local names for the gharial include 'Lamthore gohi' and 'Chimpta gohi' in [[Nepali language|Nepali]], whereby gohi means crocodile; 'Gharial' in [[Hindi languages|Hindi]]; 'Susar' in [[Marathi language|Marathi]]; 'Nakar' and 'Bahsoolia nakar' in [[Bihari languages|Bihari]]; 'Thantia kumhira' in [[Odia language|Odia]], with 'thantia' being derived from the [[Sanskrit]] word 'tuṇḍa' meaning beak, snout, elephant's trunk; the male is called 'Ghadiala' and the female 'Thantiana' in Odia.<ref name=Daniel1983/>

==See also==
* [[Crocodiles in India]]
* [[List of reptiles of South Asia]]
{{clear}}

==References==
{{Reflist}}

==External links==
{{Commons}}
{{Wikispecies|Gavialis gangeticus}}
*{{cite web|author=Joshi, A. R.|date=2018|title=Nepali scientists deploy drones to count endangered crocodiles|publisher=Mongabay|url=https://news.mongabay.com/2018/10/nepali-scientists-deploy-drones-to-count-endangered-crocodiles/}}
*{{cite web|url=http://reptilis.net/crocodylia/gavies/gavialidae.html|website=reptilis.net|title=''Gavialidae''}}
*{{cite web|url=http://www.arkive.org/gharial/gavialis-gangeticus/|website=Arkive|title=Gharial|url-status=live|archive-url=https://web.archive.org/web/20090205184636/http://www.arkive.org/gharial/gavialis-gangeticus/|archive-date=2009-02-05}}
*{{cite web|url=http://crocodilian.com/cnhc/!ggan1.htm|website=Adam Britton|title=''Gavialis gangeticus''}}
*{{EMBL species|genus=Gavialis|species=gangeticus}}
*{{Catalogue of Life |6bef8e5a76defdae652840a7b3416c9b}}
*{{cite web|url=https://www.nationalgeographic.com/animals/reptiles/facts/gharial|archive-url=https://web.archive.org/web/20210305105741/https://www.nationalgeographic.com/animals/reptiles/facts/gharial|archive-date=March 5, 2021|website=National Geographic Society|title=Gharial|date=5 May 2016 }}
*{{cite news |date=2008 |url=https://news.bbc.co.uk/2/hi/science/nature/7755393.stm |newspaper=BBC News |title=Mystery of crocs' mass die-off}}
*{{cite web |author=Lenin, J. |title=The song of the Ganges gharial |url=http://www.india-seminar.com/2007/577/577_janaki_lenin.htm |website=www.india-seminar.com}}

{{Crocodilia|G.}}
{{Crocs}}

{{Taxonbar|from=Q17134}}
{{Authority control}}

[[Category:Gavialidae]]
[[Category:Crocodilians of Asia]]
[[Category:Reptiles of India]]
[[Category:Reptiles of Nepal]]
[[Category:Reptiles of Bangladesh]]
[[Category:Critically endangered fauna of Asia]]
[[Category:Extant Pliocene first appearances]]
[[Category:Reptiles described in 1789]]
[[Category:Taxa named by Johann Friedrich Gmelin]]
[[Category:Apex predators]]