Gharial

Class: Reptilia
Order: Crocodylia
Family: Gavialidae
Genus and Species: Gavialis gangeticus
  • long-nosed looking alligator
  • long-nosed looking alligator
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Gharial

With a distinctive narrow snout it shares only with the false gharial, gharials are immediately recognizable. They are native to rivers in Asia, where they once nearly faced extinction. Still critically endangered, conservation efforts are helping to bolster their numbers.

Physical Description

The gharial has the characteristic elongated, narrow snout, similar only to the false gharial. Variation in snout shape occurs with age. It generally becomes proportionally shorter and thicker with age. The bulbous growth on the tip of the male's snout is called a "ghara" and is present in mature individuals. It has several functions attributed to it, most notably as a vocal resonator (that produces a loud buzzing noise during vocalization) and as a visual signal to females.

Many sharp, interlocking teeth line the elongated jaws, an adaptation to their fish diet. They are poorly equipped for locomotion on land. Their leg musculature is not suited to raise the body of an adult off the ground or to produce the "high-walk" gait. They can only push their bodies forward across the ground, known as "belly-sliding." They are, however, agile in the water. The narrow tail is well developed, and the rear feet have extensive webbing.

Size

The gharial is one of the largest of all crocodilian species, approaching the Australian saltwater crocodile--the largest crocodilian--in maximum size. Males reach 20 to 23 feet (6 to 7 meters) in length.

Native Habitat

Gharials are found in the rivers of the northern India subcontinent, including: Bangladesh (where they are close to being extirpated), Bhutan (possibly extirpated), India, Burma (possibly extirpated), and Nepal and Pakistan (possibly extirpated). They are found within the river systems of the Brahmaputra in Bhutan and India, the Indus River in Pakistan, the Ganges River in India and Nepal, and the Mahanadi River in India, with small populations in the Kaladan and the Irrawaddy in Burma.

They are more adapted to an aquatic lifestyle in large rivers.

Food/Eating Habits

The diet changes as the gharial matures from a juvenile to an adult. The juveniles are well suited to deal with a variety of invertebrate prey such as insects, plus smaller vertebrates such as frogs, but they mainly eat small fish. Adults are primarily fish-eaters, for which their jaws and teeth are perfectly adapted. The thin shape gives the snout low resistance in water that is suited to fast, sideways snatching movements underwater. The teeth are ideally suited for holding struggling prey such as slippery fish. Some of the larger gharials are more opportunistic and take larger prey, including mammals.

At the Smithsonian's National Zoo, they are fed a variety of fish species.

Reproduction and Development

Females reach sexual maturity around 8 to 9 feet (2.4 to 2.7 meters) in length; this is usually over 7 years of age. The males do not mature until about 13 feet (3.9 meters) in length and 15 to 18 years of age. Males guard a territory in which several females live. The mating period occurs for two months during December and January. Nesting occurs from March to May (the dry, low water season). Gharials are hole nesters and excavate an egg chamber into the sandy banks above the flood line. Up to 60 eggs are deposited into the hole before it is covered over carefully. The eggs are the largest for any crocodilian species, weighing on average 6 ounces (160 grams). Sex is determined by temperature. After 83 to 94 days, the hatchlings emerge; the female assists the hatchlings into the water as in many other crocodilian species. Protection of the young does occur around the nesting area for some time after hatching.

Lifespan

The gharial's lifespan is unknown.

Gharials are critically endangered—one of the most critically threatened of all crocodilians. The species came alarmingly close to extinction in the 1970s. Full protection was granted in the 1970s in the hope of reducing poaching losses. There are now nine protected areas for this species in India alone. They are linked to both captive breeding and ranching operations where eggs collected from the wild are raised in human care and then released back into the wild, much like some salmon and sea turtle management. The first were released in 1981.

Today, more than 3,000 animals have been released through these programs. Although breeding is successful, the overall wild population is still decreasing. The wild population in India is estimated at around 1,500 animals. In the remainder of the gharial range there are perhaps between 100 and 200 total animals.

The major threat at present is habitat loss due to human encroachment, and disruption of populations through fishing and hunting activities. A lack of suitable release sites has also started to become a management problem. Eggs are collected for medicinal purposes and males are still hunted for the aphrodisiac properties associated with the snout. They may also be snared in fishing nets and killed by fishermen. The decline in gharial populations have been linked to a decline in fish catches, because "trash" fish, of no interest to the fishermen, form a major part of the gharials diet.

Plans for the future include surveys of areas such as Pakistan and Burma where the status of the gharial in the wild is unknown; it is suspected to be very poor and the gharial is possibly extinct in these countries. But management and conservation programs cannot proceed without good data to back them up. Existing management programs also need to be refined, especially where river systems are shared by more than one country. Although poorly equipped to devour a human, gharials and most crocodilians are able to do so. Human remains and jewelry have been found in their stomachs and were thought to validate this fear, but these were most likely scavenged from corpses. The Hindi funeral ritual ends with the remains of the cremated body being sent down the river. Jewelry is possibly ingested in the same way that stones would be in order to be used as gastroliths--hard objects that presumably aid in digestion and add weight to alter buoyancy.