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Saturday, July 2, 2011

Turtles in 22 Species of Auatic Turtles

Turtles
 The varied usage of the words “turtle” and “tortoise” in English has given use to much confusion. In proper usage, tortoise refers to the strictly land dwellers with elephant like stubly feet, “turtles” are the aquatic forms inhabiting the sea, rivers and ponds with either flippers or webbed toes and “terrapins” are the hard shelled edible freshwater tortoise. Turtles are toothless but they have a beak with horney sheaths.



Turtles
 They chew their food only to reduce in for swallowing. They are omnivorous, and like other reptiles, can survive without food for months. All turtles nest on land. Their maximum life span is 100 years or a little more but it is certain that they live longer than any other vertebrates including man. They vary greatly in size, from 72 cm to the 1.8 m long. Five kinds of exclusively sea living turtles, 22 species of aquatic turtles and / or tortoise, and 4 varieties of land tortoise are found in India.

Sea Turtles

Key to Genera of Turtle
1a. Horny scutes on carapace imbricated (overlapping in all except in all very old specimens‐‐Eretmochelys
1b. Horny scutes on carapace juxtaposed (not imbricated)
2a. Four pairs of lateral (coastal) scutes on carapace; edge of lower jaw coarsely toothed; a single pair of prefrontal scutes; a single pair of claws on flippers‐‐Chelonia
2b. Five or more pairs of lateral (coastal) scutes on carapace; 2 claws on each flipper
3a. Four pairs of inframarginal scutes on the bridge of the plastron, each with a small perforation or pore toward their hind margin; carapace semicircular‐Lepidochelys
3b. Three pairs of enlarged inframarginal scutes without pores on the bridge of the plastron; carapace heart shaped‐Caretta.

Chelonia mydas exists throughout southward areas to 25o, especially around islands in the Mozambique Channel, Gulf of Oman, the ‘Gulf’ and the Gulf of Aden. Other subspecies of green turtle are found in the
Atlantic and in the eastern and Central Pacific oceans. The main nesting areas are located on the islands of Mauritus, Europe, Aldaba, Comoro and Seychelles. The most important nesting areas are found on the
coasts of Pakistan and slightly south of the west Indian borders; other important nesting beaches exist in northern Mozambique and on the southwest coast of Madagascar. The major nesting beaches for this
species are outside the area, on the northeast coast of India, Orissa district.

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