The Marine Turtles date back in evolutionary terms to the period when dinosaurs roamed the earth, and their anatomical and physiological features have undergone little change since then. They live to the age of hundred years or more and, when fully grown, can weigh from 200 to 600 pounds, depending on age.
The Green Turtle is a reptile of the Order Testudinata, so-called because of the bonny plates (Scutes) on the outer surface of the body. These bonny plates are so fused as to form an outer shell which is known dorsally as carapace and ventrally as plastron. This outer shell is light to dark brown in colour with a tinge of olive, and the four pairs of lateral scutes are distinguishing features of the green turtle, as is the single claw on each paddle shaped flipper.
The nesting season of Green Turtle starts from September and goes on to November, although the turtles do come up in fewer numbers all through the year to nest. The number of eggs laid, on any one occasion, is approximately one hundred. The entire nesting process takes around five hours, starting from the emergence of the turtle from the sea onto the beach, her search for a suitable nesting site, the excavation of the nest, laying the eggs, covering up the nest and camouflaging it, and then, finally walk back to the sea.
The incubation period for the eggs averages between forty to fortyfive days and the number of hatchlings varies according to the season and climatic conditions. Once the hatchlings emerge from eggs they must walk from the nest to the sea. This is the most hazardous stage of their life-cycle because they are easily attackable by birds, dogs and other predators. The hatchlings reach maturity between eight to thirteen years, when they return to the beaches to lay eggs. The males are, however, seldom seen as they spend almost all of their lives in the water.
The Sind Wildlife Management Board in collaboration with the WWF/IUCN has started a ‘protection and research programme for the marine turtles. It is a part of the ‘programme’ to make public aware of the threats to the existence of these completely harmless and vulnerable creatures which are struggling for survival. The turtles should not be disturbed or harassed during the nesting cycle and the eggs should be allowed to hatch without damage to the nest by dogs or poaching humans.
The potential for developing the spectacle of nesting and hatching of the turtles, as a tourist attraction is considerable, and the economic advantages of such a move make the conservation of green turtle really worthwhile.
Pakistan Post Office is issuing a stamp of 40 paisa denomination depicting a rare variety of marine turtle(Green Turtle—Chelonia mydas), on the 20th June, 1981. It is a part of series of Wildlife stamps being issued by Pakistan Post Office to focus world attention on preservation of Wildlife. Earlier issues on Wildlife include a set of two stamps each on (i) Black Partridge (30th September, 1975), (ii) Urial (31st December, 1975), (iii) Peacock (31st March, 1976), (iv) lbex (12th July, 1976) and (v) a set of four stamps depicting four rare varieties of Pheasants, namely Monal, White crested Kalij, Koklas and Cheer (17th June, 1979).