Big-headed turtle
{{Short description|Species of turtle}}
{{for |the similarly named species from Madagascar |Madagascan big-headed turtle}}
{{Speciesbox
| name = Big-headed turtle
| image = Zolw wielkoglowy.jpg
| image_caption = A big-headed turtle (Platysternon megacephalum)
| status = CR
| status_system = IUCN3.1
| status2 = CITES_A1
| status2_system = CITES
| status2_ref = {{Cite web|title=Appendices {{!}} CITES|url=https://cites.org/eng/app/appendices.php|access-date=2022-01-14|website=cites.org}}
| display_parents = 3
| grandparent_authority = Gray, 1869{{Harnvb|Rhodin|2010|pp=000.107}}
| genus = Platysternon
| parent_authority = Gray, 1831
| species = megacephalum
| authority = Gray, 1831
| synonyms =
; Platysternon megacephalum megacephalum
- Platysternon megacephalum Gray, 1831
- Platisternon megacephalus Gray, 1834
- Platysternon megacephalus Gray, 1835
- Emys megacephala Schlegel, 1838
- Platysternon magacephalum Fitzinger, 1843 (ex errore)
- Platysternum megacephalum Boulenger, 1889
- Platysternon platycephalum Mertens, 1959 (ex errore)
- Platysternum megalocephalum Stanek, 1959 (ex errore)
- Platysternon megacephalum megacephalum Wermuth, 1960
- Platysternon magacephalum megacephalum Pritchard, 1979
- Platysternon megacephalum tristernalis Schleich & Gruber, 1984
- Platysternon megacephalum tristornalis Alderton, 1988 (ex errore)
; Platysternon megacephalum peguense
- Platysternon peguense Gray, 1870
- Platysternon megacephalum peguense Wermuth, 1960
- Platysternon megacephalum vogeli Wermuth, 1969
- Platysternon megacephalum penguense Nutaphand, 1979 (ex errore)
- Platysternon megacephalum penuense Nutaphand, 1979 (ex errore)
- Platysternon megacephalum peguensis Sharma, 1998 (ex errore)
; Platysternon megacephalum shiui
- Platysternon megacephalum shiui Ernst & McCord, 1987
}}
The big-headed turtle (Platysternon megacephalum) is a species of turtle in the family Platysternidae from Southeast Asia and southern China.
Background
Previously considered a distinct family placed on occasion in "Kinosternoidea", it was later moved to the Emydidae. This, as well as the subfamily and the genus Platysternon, are monotypic.
The big-headed turtle is named after its unproportionally large head which leads to an inability to retreat into its shell. In order to protect itself it instead has an armored head and sharp beak.{{Cite web |title=The Big-headed Turtle (Platysternon megacephalum) Project |url=https://asianturtleprogram.org/big-headed-turtle-project/ |access-date=2023-04-20 |website=asianturtleprogram.org |language=en-US}}
Distribution
Behaviour
File:Platysternon megacephalum Hardwicke.jpg|left]]
The big-headed turtle is known to readily climb over obstacles in and around rivers and fast streams, using its tail as a prop to extend the reach of its strong claws. It also uses its beak to assist in climbing.[http://www.unc.edu/~dtkirkpa/stuff/bigheads.html Kirkpatrick, David T. 1995. Platysternon megacephalum. Reptile & Amphibian Magazine, November/December 1995, pages 40 – 47. C/R.] {{webarchive |url=https://web.archive.org/web/20110522230829/http://www.unc.edu/~dtkirkpa/stuff/bigheads.html |date=May 22, 2011 }} Retrieved 2012-11-25. It has been reported to climb trees and bushes. These turtles generally move more during the night, and are not prone to moving long distances. They have a general daily range of 0-89.6m and males tend to move further than the females in this species.{{Cite journal |url=https://meridian.allenpress.com/ccb/article-abstract/9/2/154/26989/Movements-and-Microhabitat-Use-of-Translocated-Big |access-date=2023-02-10 |journal=Chelonian Conservation and Biology|doi=10.2744/CCB-0833.1 |title=Movements and Microhabitat Use of Translocated Big-Headed Turtles (Platysternon megacephalum) in Southern China |date=2010 |last1=Shen |first1=Jian-Wei |last2=Pike |first2=David A. |last3=Du |first3=Wei-Guo |volume=9 |issue=2 |pages=154–161 }} They are not strong swimmers, and when swimming, this species occasionally arches its tail in the manner of a scorpion. The big-headed turtle cannot pull its head in its shell. That being the case, it will not hesitate to use its powerful jaws to defend itself. Its diet consists of fish, snails and worms.{{Cite web|url=https://animaldiversity.org/accounts/Platysternon_megacephalum/|title=Platysternon megacephalum (Big-headed Turtle)|website=Animal Diversity Web }} It also tends to eat fruits like the Machilus spp., as well as insects, crabs and mollusks.{{Cite journal |last1=Sung |first1=Yik-Hei |last2=Hau |first2=Billy |last3=Karraker |first3=Nancy |date=2016-01-01 |title=Diet of the endangered big-headed turtle Platysternon megacephalum |url=https://digitalcommons.uri.edu/nrs_facpubs/105 |journal=Natural Resources Science Faculty Publications |volume=4 |pages=e2784 |doi=10.7717/peerj.2784|pmid=27994979 |pmc=5157187 |doi-access=free }}
Diet
Originally assumed to be strictly carnivorous, this appears to be an opportunistic feeder with a significant shift towards omnivory or herbivory. Using fecal matter, big-headed turtles are found to consume fruits (Machilus and Turpinia arguta), terrestrial insect adults/larva and aquatic larva (Coleoptera, Homoptera, Hymenoptera, Isoptera, Lepidoptera, Mantodea, Orthoptera, Diptera, Ephemeroptera, Odonata and Tricoptera), mollusks (Sulcospira hainanensis), frogs, rodents, and freshwater crabs. Their eating behavior changes depending on the environmental conditions, but predominantly consume fruits. Seeds partially digested were found to have increased germination success after turtle excretion, possibly connecting their frugivore habits to environmental conditions.{{Cite journal |last1=Sung |first1=Yik-Hei |last2=Hau |first2=Billy C.H. |last3=Karraker |first3=Nancy E. |date=2016-12-13 |title=Diet of the endangered big-headed turtle Platysternon megacephalum |journal=PeerJ |language=en |volume=4 |pages=e2784 |doi=10.7717/peerj.2784 |doi-access=free |issn=2167-8359 |pmc=5157187 |pmid=27994979}}
Exploitation
The big-headed turtle is found quite frequently in illegal wildlife trade. It is readily consumed in Asia and is frequently a market item. Hunters capture them on lines with baited straight pins, so this species is rapidly disappearing in the wild.James E. Barzyk [http://www.tortoisetrust.org/articles/asia.html Turtles in Crisis: The Asian Food Markets]. The article itself is not dated, but mostly refers to data in the range 1995-2000. The species is also threatened by its use in the pet trade.
Subspecies
- P. m. megacephalum, China, 1831
- P. m. peguense, Myanmar and Thailand, 1870
- P. m. shiui, Cambodia, Laos and Vietnam, 1987
In addition, two other subspecies, P. m. tristernalis (1984) and P. m. vogeli (1969), have been given, but may be invalid.[http://www.unc.edu/~dtkirkpa/stuff/bigheads.html Platysternon megacephalum] {{webarchive |url=https://web.archive.org/web/20110522230829/http://www.unc.edu/~dtkirkpa/stuff/bigheads.html |date=May 22, 2011 }}
File:Platysternon megacephalum MHNT CHE 1992-19.jpg|center]]
== References ==
{{Reflist}}
;Bibliography
- {{Anchor|CITEREFRhodin2010}}{{cite web |url=http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_000_checklist_v3_2010.pdf |title=Turtles of the World 2010 Update: Annotated Checklist of Taxonomy, Synonymy, Distribution and Conservation Status |date=2010-12-14 |access-date=2010-12-15 |last=Rhodin |first=Anders G.J. |author2=Paul van Dijk, Peter |author3=Iverson, John B. |author4=Shaffer, H. Bradley |archive-url=https://web.archive.org/web/20110717125632/http://www.iucn-tftsg.org/wp-content/uploads/file/Accounts/crm_5_000_checklist_v3_2010.pdf |archive-date=2011-07-17 |url-status=dead }}
- {{Anchor|CITEREFritz2007}}{{cite web |url=http://www.cnah.org/pdf_files/851.pdf |title=Checklist of Chelonians of the World |date=2007-10-31 |access-date=2010-12-29 |last=Fritz |first=Uwe |author2=Havaš, Peter |archive-url=https://web.archive.org/web/20110501060224/http://www.cnah.org/pdf_files/851.pdf |archive-date=2011-05-01 |url-status=dead }}
- Pritchard, D. 1979. Encyclopedia of Turtles. New Jersey: T.F.H. Publications, Inc. Ltd.
- "The Big-headed Turtle (Platysternon megacephalum) Project". asianturtleprogram.org. Retrieved 2023-03-14
External links
{{Commons}}
- [https://web.archive.org/web/20111209224040/http://www.unc.edu/~dtkirkpa/stuff/bighead2.html Big-headed turtle (Platysternidae)]
- (Chinese) [http://www.herpera.com/bigheaded.htm Big-headed turtle]
- (Spanish) [http://www.infotortuga.com/platysternon.htm Platysternon megacephalum] {{Webarchive|url=https://web.archive.org/web/20160304051116/http://www.infotortuga.com/platysternon.htm |date=2016-03-04 }}
{{Testudines}}
{{Taxonbar|from1=Q14566127|from2=Q754035}}
Category:Reptiles of Hong Kong
Category:Reptiles described in 1831
Category:Taxa named by John Edward Gray