Gharial

Taxonomy

Order: Crocodylia
Family: Gavialidae
Genus/species: Gavialis gangeticus

Description:

The gavial or gharial (common name) has a characteristic elongated, narrow snout, similar only to the false gharial, (Tomistoma schlegelii). 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" (after the Indian word meaning "pot"), and is present in mature individuals. Two possible functions have been attributed to it: as a vocal resonator (which produces a loud buzzing noise during vocalization) and as a visual signal to females.

The elongated jaws are lined with many interlocking, razor-sharp teeth, an adaptation to their fish diet. 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 m) in length.

The gharial is poorly equipped for locomotion on land. Its leg musculature is not suited to raise the body off the ground or to produce the "high-walk" gait. It is able only to push its body forward across the ground or "belly-slide." It is, however, very agile in the water. The tail is well-developed and laterally flattened, and the rear feet possess extensive webbing.

The gharial has 106 to 110 teeth in the elongated snout.

Distribution and Habitat:

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

They are more adapted to an aquatic lifestyle in the calmer areas of deep, fast-moving rivers. They usually leave the water only to bask and nest, both of which usually occur on sandbanks.

Diet in the Wild:

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 primarily 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, which is suited to fast lateral 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.

Zoo Diet:

The Zoo's gharial is fed a variety of fish species. The larger fish, tilapia, in its enclosure were tried as a possible feeder fish, but because of the fish’s speed they are rarely caught.

Reproduction:

Females reach sexual maturity around eight to nine feet (2.4 to 2.7 m) in length, this is usually when they are older than seven years of age. The males do not mature until about 13 feet (3.9 m) in length at 15 to 18 years of age.
Males guard a territory in which several females live. The mating period lasts 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 of any crocodilian species, weighing on average six ounces (160 g). After 83 to 94 days, the hatchlings emerge, and the females assist the hatchlings to the water as in many other crocodilian species. However, protection of the young does occur around the nesting area for some time after hatching.

Life Span:

Unknown

Status:

The gharial is listed as critically endangered on the IUCN Red List of Threatened Species. The species is considered to be one of the most critically threatened of all crocodilians, and was alarmingly close to extinction in the 1970s. They are listed on Appendix I of CITES.

Fortunately, there has been some recovery, and a reasonable amount of hope lies with the conservation and management programs now in place. 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 captivity 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. But still, the total population, wild and captive, is estimated at under 1,000 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 problem for the management of the gharial. 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, as predatory fish, of no interest to the fishermen, form a major part of the gharial 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. 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, such ability has nevertheless been attributed to the gharial and indeed most crocodilians. Human remains and jewelry have been found in their stomachs, serving to validate this fear. 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, which presumably aid in digestion and add weight to alter buoyancy.

Fun Facts:

Gharials are named for the bulbous structure on the tip of the snout in adult males. The word gharial is derived from the Hindi word, "ghara," which means, "mud pot." It was misread by Europeans who changed the word to gavial. Thus, Gavialis gangeticus is known both as gavial and gharial.

The gharial is the most long-snouted and together with the saltwater crocodile the largest of the living crocodilians. A male gharial can reach 20 feet (6 m).

The National Zoo exhibits one female gharial; a gift from the government of Nepal.