Saturday, July 2, 2011

Crocodiles Under Water and Type Crocodiles

The body is covered with a rough hide like skin, underlined by bony plates. The elongated snout terminates in a rather bulbous nose with the nostrils positioned on top so as to enable the crocodiles to breathe without difficultly when the body is submerged. The eyes, which are also placed high on the head, are well protected by the eyelids and a movable transparent membrane so that the vision is not affected under water.


 The throat is provided with a fleshy valve that would permit the crocodiles under water to pursue the prey, without the risk of drowning. The tail is highly muscular and propels the reptile through water easily. The colouration of the adults is rather dull, but the young ones are brightly coloured, with dark brown spots or bars on the back.


The three species of crocodiles found in India are mugger (Crocodylus palustris), the salt water or estuarine crocodile (Crocodylus porosus), and the gharial or gavial (Gavialis gangeticus). Easy identification of gharial, mugger and salt waters crocodiles can be made with the shape of head and jaws The three crocodilians found in India may be easily identified: the gharial (right) has the thinnest jaws. The mugger (middle) has the broadest. The saltwater crocodile (left) has a longer snout than the mugger and no large scales behind its head.

Family Crocodillies :
- Salt Water Crocodile or Salt Water Crocodile Crocodylus porosus Schneider
- Marsh Crocodile Crocodylus palustris Lesson
Salt Water Crocodile Crocodylus porosus Schneider

Salt Water Crocodile
 The Salt Water Crocodile or estuarine crocodiles are recognized by longer muzzle and two prominent ridges running forward from the eyes and converging on the nose. The Salt Water Crocodile colour is dark olive green or brown or almost black above, and lemon yellow on the underside. The eye is yellow. It is really known to reach a length of 7 meters, although most specimens today are under 4.30 metres.

Salt Water crocodile
This Salt Water crocodile species is a truly seagoing reptile, which prefers mangrove swamps, deltas, estuaries and coasts as its habitats. It principally feeds upon fish and crustaceans, but also takes birds and mammals. The female lays from 40 to 60 eggs and buries them in to a mounded‐type nest. Incubations lasts from 75 to 90 days.

Marsh Crocodile Crocodylus palustris Lesson

Marsh Crocodile

Marsh Crocodile or Crocod ylus palustris is short and is devoid of any ridges. A square of four shields on the nape with four distinct scales between the large shield and the broad head are the most obvious features. The colour is olive or pale, with prominent dark spots in young, and black in adults. It may reach a length of 4 meters, but most specimens are under 3.25 meters.

Marsh Crocodile
 Although the species is called “Marsh Crocodile”, it is by no means restricted to marsh lands, but is also found in rivers, lakes and man‐made reservoirs, ponds or tanks. It is reported even from the Himalayan foothills and the salt lakes adjacent to estuarine area. Its principal food includes fish, frogs and crustaceans but occasionally turtles, birds and mammals.

In mangrove area, the reptiles like amphibians are occurring in different environments such as forest, land, water etc. Crocodiles are widely distributed in Asia, Africa, Madagascar, Australia, Papua New Guinea
and in North and South America. At present the estuarine crocodile is confined within India to parts of the east coast of mainland and the Andaman and Nicobar Islands. It is recorded outside India mainly from the coasts of Sri Lanka, Burma, Malaya and Indo‐China through the Malay Archipelago to the Philippines, Northern Australia, New Guinea and Solomon Islands.

The marsh crocodile is widely distributed in India although populations are fragmented and isolated. Its area of occurrence outside India includes Iran, Pakistan, Nepal, Bangladesh and Sri Lanka. Indopacific crocodiles Crocodylus porosus are abundant in the upper mangroves of the Kias river, Sabah, Malaysia. Small numbers are found in the Sundarbans where it has been depleted by hunting. In Orissa a population of 35 adults is found in the Bhitarkanika wild life sanctuary (Bustard and Choudhury, 1981). Populations are depleted in Andaman islands between 170 and 330.

The population in the Nicobar is reported to be healthy but no precise data are available (Choudhury and Bustard,1979). The Nicobar may be its last stronghold in India (Bagla and Menon, 1989). Breeding programmes are operated through the West Bengal Forest Department; the Orissa State Forest Department; and the Madras Crocodile Bank. Hatchlings are released in Bhtarkanika; in the project Tiger Reserve (Sundarbans); and in the Coringa Wildlife Sanctuary (Luxmoore et al., 1985). There is an urgent need for habitat protection and the species has received some protection in the Mahanadi
Delta (Scott, 1989).


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