Thursday, June 16, 2011

Gharial

Gharial

                                                                   (Gavialis gangeticus)




  • The gharial (Gavialis gangeticus), ( Hindi: घऱियाल, Marathi: सुसर Susar), also called Indian gavial or gavial, is the only surviving member of the once well-represented family Gavialidae, a long-established group of crocodilians with long, slender snouts. The gharial is listed as a critically endangered species by IUCN. The gharial is one of the three crocodilians found in India, the others being the Mugger crocodile and the Saltwater crocodile. It is one of the longest of all living crocodilians.




  • Description: The Gharial, Gavialis gangeticus is uniformly dark olive-gray with a pale yellow belly. Juveniles have dark spots and cross bands against a light background. Gharials have an extremely elongated snout. The teeth are needle-like and the eyes green frosted with back. A large male can reach 23 feet in length, and a female 15 feet.Gharials, being the most aquatic of all crocodilians, are awkward out of water mainly due to their short stumpy legs. The adult male develops a pot-like structure on the end of the snout, giving the gharial its name (from    "ghara" -- Hindi for earthen pot). This nose knob is used to produce a bussing noise that repels rival males and serves as an audible warning system.  The leg musculature of the gharial does not enable it to raise its body off the ground to achieve the high-walk gait on land, but can only push its body forward across the ground ('belly-sliding'), although it can do this with some speed when required. However, when in water, the gharial is the most nimble and quick of all the crocodilians in the world. The jaws are lined with many interlocking, razor-sharp teeth — 27 to 29 upper and 25 or 26 lower teeth on each side. These teeth are not received into interdental pits; the first, second, and third mandibular teeth fit into notches in the upper jaw. The front teeth are the largest. The gharial's snout is narrow and long, with a dilation at the end and its nasal bones are comparatively short and are widely separated from the pre-maxillaries.

  • Distribution and Habitat: Gharials thrive in deep rivers. They are powerful swimmers but graceless on land, and will leave the water only to bask or to nest on sandy beaches. They were once distributed across approximately 20,000 square kilometres (7,700 sq mi) of riverine habitat of the Indus, Ganges, Brahmaputra, and Irrawady river systems. Today their distribution is limited to only 2% of their former range. In India, small populations are present and increasing in the rivers of the National Chambal Sanctuary, Katarniaghat Wildlife Sanctuary, Son River Sanctuary and the rainforest biome of Mahanadi in Satkosia Gorge Sanctuary, Orissa, where they apparently do not breedIn Nepal, small populations are present and slowly recovering in tributaries of the Ganges, such as the Narayani-Rapti river system in Chitwan National park and the Karnali-Babai river system in Bardia National Park.

  • Diet: Young gharials eat insects, larvae, and small frogs. Mature adults feed almost solely on fish, although some individuals have been known to scavenge dead animals. Their snout morphology is ideally suited for preying on fish. Their long, narrow snouts offer very little resistance to water in swiping motions to snap up fish in the water. Their numerous needle-like teeth are ideal for holding on to struggling, slippery fish. Gharials will often use their body to corral fish against the bank where they can be more easily snapped up.

  • Threats: Gharials have been pushed to the brink of extinction. In 1974, the government of India and the United nations Food and Agriculture Organization conducted a survey of its population in India. It was estimated that no more than 50 to 60 surviving adults.Although the gharial is still listed as endangered, effective conservation measures have now made the gharial's future more promising. Massive sanctuaries have been created and active management involves the collection of eggs for hatchery incubation.