Tomistoma Task Force

Official site for Tomistoma Conservation action with the CSG's TTF!

Tomistoma

Scientific name: Tomistoma schlegelii

Common names:  There are many common names for Tomistoma schlegelii.

Names may be specific to certain languages, cultures and countries, or may be translations of English names. The name “False Gharial” derives from this species’ similarity to Gavialis gangeticus or “Indian Gharial”. A similar name is “False Gavial”, so called because the “Indian Gharial” was originally referred to as a “Gavial” until it was pointed out that a “ghara” is the correct spelling of the Hindi word for “pot” that refers to the bulbous appendage on the nose of adult male gharials.

Today many authorities use the name “Tomistoma” instead of “False Gharial”, hence the “Tomistoma Task Force”. Several other species of crocodilians share a common name with their genus (eg. Alligator, Caiman) and the negative connotation that comes from being a “false” gharial is counterproductive when promoting conservation of this species in key range countries.

An incomplete list of common names used for this species is as follows: 
[English] Tomistoma, False Gharial, False Gavial, Malayan False Gharial, Malay Gharial, Malay Gavial, Malayan Fish Crocodile, Sunda Gharial; [French] Faux Gavial Malais; [Spanish] Falso Gavial Malayo; [Indonesian] Baja (Baya) Kanulong, Bediai Sampit, Boeaja, Buaja, Buaya, Buaya Jolong-Jolong, Buaya Sa(m)pit, Buaya Senjulong, Buaya Sepit, Jolong-Jolong, Senjulong, Sunda-Gavial

Etymology: 

Tomistoma means “sharp mouth”, derived from tomos (Greek for “cutting” or “sharp”) +stoma (Greek for “mouth”), referring to the slender shape of the jaws.

schlegelii means “of Schlegel”, referring to the Dutch zoologist H. Schlegel (1804-1884) who is credited with its discovery.

Taxonomy: There is much debate and confusion over the taxonomic status of Tomistoma schlegelii. The most recent fossil and morphological evidence suggests a close relationship with the Family Crocodylidae. However, there is also strong biochemical and immunological evidence that suggests a closer affinity with the Indian Gharial (Gavialis gangeticus) in the Family Gavialidae. The jury is still out on the final decision. 

Distribution:

tsch-map-large

Indonesia (Sumatra, Kalimantan, Java, possibly Sulawesi), Malaysia (Malay Peninsula, Borneo), possibly Vietnam, possibly extirpated in Thailand (none seen since 1970 except unconfirmed report in Narithawat province)

Habitat:

Freshwater lakes, rivers & swamps. Reported to use burrows. Seems to prefer vegetative cover, floating mats of vegetation and slow-moving waterways. Very little known, generally. 
 

Status:

CITES:Appendix I
IUCN Red List: EN C1 (ENDANGERED)
Estimated wild population: under 2,500

Summary: Distribution data are still relatively poor, making an accurate assessment of status, distribution or population size very difficult. Generally considered to be somewhat widespread but populations in many areas have either disappeared or are seriously depleted. Moreover, threatening processes such as habitat loss are still ongoing.

Appearance:

Characteristic slender snout, slightly more robust than the Indian Gharial (Gavialis gangeticus) from which it derives its common name. Skin colour in juveniles is a light tan with black banding and spots on the head, body and tail. Belly is generally creamy white with some white creeping onto the flanks and tail subcaudal scales. Adults retain much of the basic juvenile colouration, skin becoming shifting from light to dark tan / chocolate brown. This is a large crocodilian species, with maximum size of males generally 4 to 5 metres (13 to 16.4 feet) although unconfirmed reports of males reaching 6 metres (20.7 feet) exist. Females also grow to large sizes, although few data on maximum female size exist. Tomistoma possess between 76 and 84 teeth (4-6 premaxillary, 15-16 maxillary, 19-20 mandibular). 

tsch-headdrawing-original-s

Diet:

The elongated snout of the juveniles is ideally suited for rapid movement through water to capture a variety of invertebrates (eg. shrimps, insects, spiders) and small vertebrates (fish, frogs). Older individuals develop a more robust set of jaws that give a clue to the opportunistic nature of this species. Thought originally to specialise on fish like the Indian Gharial, adult Tomistoma actually take a much wider range of prey from relatively small invertebrates to relatively large mammals (monkeys, small deer), birds, turtles and other reptiles. In recent years, there have been reports of Tomistoma killed for preying on cattle. There are also cases of attacks on humans by Tomistoma.

Breeding:

There is very limited information available on the breeding ecology of wild Tomistoma. Females are reported to become sexually mature around 2.5 to 3 metres. Females construct mound nests of dry leaves, peat and other vegetation, often at the base of trees. Mounds can measure up to 60 cm (24 inches) in height. Tomistoma eggs are exceptionally large, typically over 100 mm in length. The number of eggs laid averages 20 to 30, although there is a report in the literature of a nest containing around 60 eggs. There are doubts whether this is genuine. It could have been either two clutches from different females, or a misidentified clutch from an Estuarine Crocodile (Crocodylus porosus) which overlap the range of Tomistoma. Eggs are incubated for around 90 days before hatchling, although like all crocodilian species the period of incubation is influenced by the nest temperature. The sex of the embryos is determined by temperature, like all crocodilian species (called temperature-dependent sex determination) although the ranges that produce males and females are not known. Hatchlings are reported to receive no parental care unlike most crocodilian species. Nests in the wild are reported to suffer high mortality from predators such as wild boar and reptiles.

Conservation:

For many years, very little information on the conservation status of Tomistoma was available. This has begun to change recently, although Tomistoma populations throughout the majority of their range remain poorly studied. Completed surveys reveal low population densities in fragmented habitat. Although some habitat lies within protected areas, enforcement for these is limited. Habitat destruction (logging, cultivation, dams, flood mitigation), drowning in fishing nets, overfishing of food resources and, to a limited extent, poaching for skins threaten the species. Captive breeding of this species has brought limited success, with only a few centres having successfully produced viable young, and more research into the factors required for successful captive breeding is required. More importantly, conservation initiatives for wild populations are urgently required. Some progress is starting to be made, and the Tomistoma Task Force has been established in 2003 to focus the efforts of crocodilian specialists from around the world.

For more information, head over to the CSG’s Action Plan.

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