Tomistoma schlegelii

Most common names (English): Tomistoma, False Gharial, Malay Gharial
Local names: Buaya Supit (“chopstick crocodile” – Bahasa Indonesia), Limburan (Bahasa Kutai)
The species was first described by S. Müller in 1838. Tomistoma means “sharp mouth”, derived from Greek words tomos (“sharp”) and stoma (“mouth”). schlegelii means “of Schlegel” – a Dutch zoologist, who’s credited with first discovering the species.



Are they endangered?

They are likely to be. Tomistoma is listed in CITES, Appendix I and classified as Vulnerable on IUCN Red List.
Currently there are no reliable estimates for the number of Tomistoma left in the wild. It appears the remaining populations are small and fragmented, with habitat destruction being the main cause for their decline (Stuebing et al., 2006). Tomistoma Task Force founded by the IUCN-SSC Crocodile Specialist Group is a workgroup that focuses on the biology, ecology, population status, threat identification and conservation of the species. They also support our Mesangat project. 

Where can I find them?

Right here!
(With some luck and a good spotlight) Tomistoma schlegelii can be found in freshwater peat swamp forests, adjacent wetlands, heavily overgrown lakes and swampy, slow-flowing rivers.
Indonesia: East Sumatra, West Java, Kalimantan
Malaysia: Peninsular Malaysia, Sarawak
Appears to be extinct in the wild in Thailand. But easy to spot in the crocodile farms.

What do they look like?

Tomistoma is a pretty large crocodilian – adults commonly grow to 3-4 m, sometimes 5 m. Reports of larger sizes (up to 7 m; De Rooj, 1915) can be found in older literature, but no animals of this size have been found in recent years to confirm such measurements. The largest crocodile, caught recently in the Philippines – Crocodylus porosus, named Lolong – measures 6.17 m, making C. porosus the largest crocodilian species living today. However, the world’s largest (or rather, the longest) crocodile skull, kept in the Natural History Museum in London and measuring 84 cm long, belongs to Tomistoma schlegelii (Whitaker and Whitaker, 2008). Tomistomas also lay the largest eggs of any crocodilians, measuring on average 10 cm long and 7.5 cm wide (Trutnau and Sommerlad, 2006). And even the hatchlings are large, when compared to other species.

A large Tomistoma schlegelii captured in East Kalimantan (photo: Yayasan Ulin)

Large Tomistoma schlegelii captured near Mesangat (photo: Yayasan Ulin)

T. schlegelii egg

Young T. schlegelii from Mesangat (Norman) looking friendly


The species is dark olive to chocolate brown with dark blotches on the sides that merge into cross bands on the sides and tail. The belly is light.
Tomistoma are easily distinguished from other crocodile species by their long and narrow snout, similar to that of the Indian gharial Gavialis gangetius. Recent molecular studies have also determined the two species are closely related and placed Tomistoma in the family Gavialidae (Densmore, 1983).
Tomistoma snout is 4.5 times as long as wide at its base. Only in Indian gharials this ratio is larger (6 time as long as wide at base), which makes these species particularly vulnerable to jaw breaks and injuries when mishandled. Never catch a tomistoma by its snout!

What do they do?

Mostly this

Or this

Relatively little is known about the ecology and behaviour of Tomistoma schlegelii in the wild. In Mesangat, the species is notoriously shy, rarely basks, and its cryptic colouration often makes it difficult to find it. Tomistoma builds mound nest at a base of a tree near the water’s edge and does not appear to care for young once they hatch. For many years it was thought that tomistomas feed primarily on fish, since the long slender snout and protruding teeth – similar to the fish-eating Indian gharial – allow for quick movements in the water to catch fast slippery prey. However, other animals, such as birds and monkeys have also been reported as prey (Gladikas 1985; Yeager, 1991). Wild tomistoma ecology, including diet and nesting biology are currently studied in Mesangat.

Do they eat people?

Very rarely. Despite its large size very few attacks on people have ever been reported (Kurniati, 1998, Rachmawan and Brend, 2009). Tomistoma schlegelii is a shy species that prefers to avoid humans. Local people in Mesangat believe it to be a “good crocodile” and it is bad luck to harm it. However, as any large crocodilian, it’s an ambush predator with a powerful bite and can be very dangerous if mishandled or accidentally stepped on. 

Big teeth!
 

Want to know more? References and further reading:

Books:

Trutnau, L., Sommerlad, R. (2006) Crocodilians: Their Natural History and Captive Husbandry. Chimara, Frankfurt am Main
All you could ever wish to know about crocodiles.

Websites:




Papers:

Bezuijen, M.R., Webb, G.J.B., Hartoyo, P., Samedi. 2001. Peat swamp forest and the false gharial Tomistoma schlegelii (Crocodilia, Reptilia) in the Merang River, eastern Sumatra, Indonesia. Oryx 35: 301-307

Densmore, L.D. 1983. Biochemical and immunological systematic of the order Crocodilia. Evolutionary Biology 16: 397-465

Gladikas, B.M.F. 1985. Crocodile predation on a proboscis monkey in Borneo. Primates 26: 495-496

Kurniati, H. 1998. Six people were killed by Tomistoma in Central Kalimantan. Crocodile Specialist Group Newsletter 17: 9

Rachmawan, D., Brend, S. 2009. Human - Tomistoma interactions in Central Kalimantan, Indonesian Borneo. Unpublished Report, Orangutan Foundation, Indonesia.

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: 181-197

Stuebing, R., Sommerlad, R. & Staniewicz, A. (2015): Conservation of the Sunda gharial Tomistoma schlegelii in Lake Mesangat, Indonesia. International Zoo Yearbook 49: 137–149

Whitaker, R.,Whitaker, N. 2008. Who’s got the biggest? CrocodileSpecialist Group Newsletter 27:26-30

Yeager, C.P. 1991. Possible antipredator behaviour associated with river crossing by proboscis monkeys (Nasalis larvatus). American Journal of Primatology 24: 61-66