False gharial
False gharial | |
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Captive false gharial in Berlin Zoo, Germany
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Clade: | Archosauromorpha |
Clade: | Archosauriformes |
Order: | Crocodilia |
Family: | Gavialidae |
Subfamily: | Tomistominae |
Genus: | Tomistoma Müller, 1846 |
Species: | T. schlegelii
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Binomial name | |
Tomistoma schlegelii (Müller, 1838)
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Range of the false gharial | |
Synonyms | |
Pseudogavialis schlegelii |
The false gharial (Tomistoma schlegelii), also known by the names Malayan gharial, Sunda gharial and tomistoma, is a freshwater
The specific name schlegelii honors Hermann Schlegel.[3][4]
Characteristics
The false gharial is dark reddish-brown above with dark brown or black spots and cross-bands on the back and tail.
The false gharial has one of the slimmest snouts of any living crocodilian, comparable to that of the
Three individuals ranging from 2.9 to 4.05 m (9 ft 6 in to 13 ft 3 in) in length and weighing from 79 to 255 kg (174 to 562 lb) had a
Taxonomy
The
The genus
The false gharial's snout broadens considerably towards the base and so is more similar to those of true
Fossils of extinct Tomistoma species have been found in deposits of Paleogene, Neogene, and Quaternary ages in Taiwan, Uganda, Italy, Portugal, Egypt and India, but nearly all of them are likely to be distinct genera due to older age compared to the false gharial.[24]
The below cladogram of the major living crocodile groups is based on molecular studies and shows the false gharial's close relationships:[18][21][22][15][23]
Crocodilia |
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The following cladogram shows the false gharial's placement within the Gavialidae; it is based on a
Gavialoidea |
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( stem-based group )
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Distribution and habitat
False gharials are native to Peninsular Malaysia, Sarawak, and Indonesia (Sumatra, and Borneo), but were extirpated in Singapore, Vietnam, and Thailand. It is unclear if they remain in Java. Apart from rivers, they inhabit swamps and lakes.[2] The species is almost entirely found today in peat swamps and lowland swamp forests.[25] In the 1990s, information and sightings were available from 39 localities in 10 different river drainages, along with the remote river systems of Borneo.[citation needed]
Prior to the 1950s, Tomistoma occurred in freshwater ecosystems along the entire length of Sumatra east of the Barisan Mountains. The current distribution in eastern Sumatra has been reduced by 30-40% due to hunting, logging, fires, and agriculture.[26]
Ecology and behaviour
Diet
Until recently, very little was known about the diet or behaviour of the false gharial in the wild. Details are slowly being revealed. In the past, the false gharial was thought to have a diet of only fish and very small
The false gharial may be considered an ecological equivalent to
Reproduction
False gharials are mound-nesters. Females lay small clutches of 13 to 35 eggs per nest, and appear to produce the largest eggs of extant crocodilians. Sexual maturity in females appears to be attained around 2.5 to 3 m (8.2 to 9.8 ft), which is large compared to other crocodilians.[26]
It is not known when they breed in the wild or when the nesting season is. Once the eggs are laid, and construction of the mound is completed, the female abandons her nest. Unlike most other crocodilians, the young receive no parental care and are at risk of being eaten by predators, such as mongooses, tigers, leopards, and wild dogs. The young hatch after 90 days and are left to fend for themselves.[citation needed]
Conflict
In 2008, a 4-m female false gharial attacked and ate a fisherman in central Kalimantan; his remains were found in the gharial's stomach. This was the first verified fatal human attack by a false gharial.[27] However, by 2012, at least two more verified fatal attacks on humans by false gharials had occurred indicating perhaps an increase of human-false gharial conflict possibly correlated to the decline of habitat, habitat quality, and natural prey numbers.[28]
Threats
The false gharial is threatened with
Conservation
The false gharial is listed on
Steps have been taken by the Malaysian and Indonesian governments to prevent its extinction in the wild. There are reports of some populations rebounding in Indonesia, yet with this slight recovery, mostly irrational fears of attacks have surfaced amongst the local human population.
References
- PMID 34567843.
- ^ a b c d e Shaney, K.; Shwedick, B.; Simpson, B.K.; Pine, A.; Sideleau, B. & Stevenson, C. (2023). "Tomistoma schlegelii". IUCN Red List of Threatened Species. 2023: e.T21981A214287051. Retrieved 11 December 2023.
- ^ Müller, S. (1838). "Waarnemingen over de Indische Krokodillen en Beschrijving van eene nieuwe Soort". Tijdschrift voor Natuurlijke Geschiedenis en Physiologie (in Dutch). 5: 61–87.
- ISBN 978-1-4214-0135-5.
- ^ Brazaitis, P. (2001) A Guide to the Identification of the Living Species of Crocodilians. Science Resource Center, Wildlife Conservation Society
- ^ S2CID 8231693.
- ^ Mathew, A., Ganesan, M., Majid, R. A., & Beastall, C. (2011). Breeding of False Gharial, Tomistoma schlegelii, at Zoo Negara, Malaysia (PDF). Zoo Negara. Archived from the original (PDF) on 2018-01-27. Retrieved 2012-06-13.
{{cite book}}
: CS1 maint: multiple names: authors list (link) - ^ Milàn, J. & Hedegaard, R. (2010). "Interspecific variation in tracks and trackways from extant crocodylians". New Mexico Museum of Natural History and Science Bulletin. 51: 15–2.
- ^ Shaney, Kyle and Shwedick, Bruce and Simpson, Boyd and Stevenson, Colin and Sideleau, B (2019). Tomistoma Tomistoma schlegelii (PDF) (4 ed.). Crocodiles: Status, Survey and Conservation Action Plan.
{{cite book}}
: CS1 maint: multiple names: authors list (link) - PMID 28942308.
- ^ Whitaker, R. and Whitaker, N. (2008). "Who's got the biggest?" (PDF). Crocodile Specialist Group Newsletter 27 (4): 26−30.
{{cite journal}}
: CS1 maint: multiple names: authors list (link) - PMID 22431965.
- ^ Müller, S. (1838). "Waarnemingen over de Indische Krokodilen en beschrijving eene nieuwe soort". Tijdschrift Vorr Naturrlijke Geschiendes en Physiologie. 5: 61–87.
- ^ Müller, S. (1846). "Über den Charakter der Thierwelt auf den Inseln des indischen Archipels, ein Beitrag zur Naturgeschichte". Archiv für Naturgeschichte. 12: 109–128.
- ^ PMID 30051855.
- .
- .
- ^ PMID 12775527.
- PMID 12775528.
- PMID 17433721.
- ^ PMID 18372192.
- ^ PMID 22431965.
- ^ PMID 33907305.
- ^ "Fossilworks: Tomistoma". Fossilworks.
- ^ a b Bezuijen, M.R.; Shwedick, B.M.; Sommerlad, R.; Stevenson, C.; Steubing, R.B. (2010). "Tomistoma Tomistoma schlegelii" (PDF). In Manolis, S.C.; Stevenson, C. (eds.). Crocodiles. Status Survey and Conservation Action Plan. Darwin: Crocodile Specialist Group. pp. 133−138.
- ^ a b Bezuijen, M.R.; Webb, G.J.W.; Hartoyo, P.; Samedi; Ramono, W.S.; Manolis, S.C. (1998). "The False Gharial (Tomistoma schlegelii) in Sumatra" (PDF). Crocodiles. Proceedings of the 14th Working Meeting of the Crocodile Specialist Group. Gland, Switzerland and Cambridge, UK: IUCN. The World Conservation Union. pp. 10–31.
- ^ a b c d Rachmawan, D.; Brend, S. (2009). "Human-Tomistoma interactions in central Kalimantan, Indonesian Borneo" (PDF). Crocodile Specialist Group Newsletter. 28 (1): 9–11.
- ^ Sideleau, B.; Britton, A. R. C. (2012). "A preliminary analysis of worldwide crocodilian attacks" (PDF). Crocodiles. Proceedings of the 21st Working Meeting of the IUCN-SSC Crocodile Specialist Group. Gland, Switzerland: IUCN Crocodile Specialist Group. pp. 111–114.
- ^ Stuebing, R. B., Bezuijen, M. R., Auliya, M., & Voris, H. K. (2006). "The current and historic distribution of Tomistoma schlegelii (the False Gharial) (Müller 1838) (Crocodylia, Reptilia)". The Raffles Bulletin of Zoology, 54(1), 181-197.
- ^ Rödder, D., Engler, J. O., Bonke, R., Weinsheimer, F., & Pertel, W. (2010). "Fading of the last giants: an assessment of habitat availability of the Sunda gharial Tomistoma schlegelii and coverage with protected areas". Aquatic Conservation: Marine and Freshwater Ecosystems, 20(6), 678-684.
- ^ "Siamese Crocodile Conservation Case Study | the Mohamed bin Zayed Species Conservation Fund".
External links
- Crocodile Specialist Group: "Tomistoma schlegelii" (PDF). (132 KB)
- Tomistoma Task Force Archived 2017-06-30 at the Wayback Machine
- Saint Louis Zoo: False gharial
- ARKive Images
- BBC News: 'Match-making' for rare male croc
- The Orangutan Foundation research centre being used for critical research on false gharials