False gharial

Appearance

The false gharial is dark reddish-brown above with dark brown or black spots and cross-bands on the back and tail. Ventrals are grayish-white, with some lateral dark mottling. Juveniles are mottled with black on the sides of the jaws, body, and tail. The smooth and unornamented snout is extremely long and slender, parallel sided, with a length of 3.0 to 3.5 times the width at the base. All teeth are long and needle-like, interlocking on the insides of the jaws, and are individually socketed. The dorsal scales are broad at midbody and extend onto the sides of the body. The digits are webbed at the base. Integumentary sensory organs are present on the head and body scalation. Scales behind the head are frequently a slightly enlarged single pair. Some individuals bear a number of adjoining small keeled scales. Scalation is divided medially by soft granular skin. Three transverse rows of two enlarged nuchal scales are continuous with the dorsal scales, which consist of 22 transverse rows of six to eight scales, are broad at midbody and extend onto the sides of the body. Nuchal and dorsal rows equals a total of 22 to 23 rows. It has 18 double-crested caudal whorls and 17 single-crested caudal whorls. The flanks have one or two longitudinal rows of six to eight very enlarged scales on each side.

The false gharial has one of the slimmest snouts of any living crocodilian, comparable to that of the slender-snouted crocodile and the freshwater crocodile in slenderness; only that of the gharial is noticeably slimmer. Males can reportedly grow up to 5 m in length. Three mature males kept in captivity measured 3.6 to 3.9 m and weighed 190 to 210 kg, while a female measured 3.27 m and weighed 93 kg. Females have been recorded at lengths of up to 4 m. The false gharial apparently has the largest skull of any extant crocodilian, in part because of the great length of the slender snout. Out of the eight longest crocodilian skulls from existing species that could be found in museums around the world, six of these belonged to false gharials. The longest crocodilian skull belonging to an extant species was of this species and measured 84 cm in length, with a mandibular length of 104 cm. Most of the owners of these enormous skulls had no confirmed total measurements for the animals, but based on the known skull-to-total length ratio for the species they would measure approximately 5.5 to 6.1 m in length. The false gharial is considered to be a large crocodilian, with one large male individual weighing 590 kg.

Three individuals ranging from 2.9 to 4.05 m in length and weighing from 79 to 255 kg had a bite force of 1,704–6,450 N.

Naming

It is listed as Vulnerable on the IUCN Red List, as the global population is estimated at around 2,500 to 10,000 mature individuals.

Distribution

False gharials are native to Peninsular Malaysia, Sarawak, and Indonesia, but were extirpated in Singapore, Vietnam, and Thailand. It is unclear if they remain in Java. Apart from rivers, they inhabit swamps and lakes. The species is almost entirely found today in peat swamps and lowland swamp forests. In the 1990s, information and sightings were available from 39 localities in 10 different river drainages, along with the remote river systems of Borneo.

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.

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, which is large compared to other crocodilians.

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.

Food

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 vertebrates, but more recent evidence indicates that it has a generalist diet despite its narrow snout. In addition to fish and smaller aquatic animals, mature adults prey on larger vertebrates, including proboscis monkeys, long-tailed macaques, deer, water birds, and reptiles. There is an eyewitness account of a false gharial attacking a cow in East Kalimantan.

The false gharial may be considered an ecological equivalent to Neotropical crocodiles such as the Orinoco and American crocodiles, which both have slender snouts but a broad diet.

Predators

The false gharial is threatened with extinction throughout most of its range due to the drainage of its freshwater swamplands and clearance of surrounding rainforests. The species is also hunted frequently for its skin and meat, and the eggs are often harvested for human consumption.