Friday, November 9, 2007

Reptilia - sea turtle and lizard

Sea turtles are reptiles. Reptiles have scales and a backbone. They are cold-blooded and they breathe with lungs. Sea Turtles are large turtles that spend most of their lives in the seas. They live in shallow coastal waters of warm and temperate seas.. All Sea Turtle species are considered endangered or threatened.

Anatomy: These cold-blooded animals are strong swimmers and good divers. They have four flipper-like legs and a shell that is attached to their backbone. They cannot pull their head and legs into the shell. These turtles vary in color from shades of brown to green to black. Sea turtles vary in size from 2 to 6 feet (0.5 to 1.9 m) long, weighing 78 to 1900 pounds (35 to 870 kg). During active times, turtles must go to the sea's surface every few minutes in order to breathe air.

Diet: Most sea turtles are carnivores (meat eaters), but the green turtle is a herbovore (a plant eater that eats sea grass and algae). Most sea turtles eat crustaceans (crabs, lobster, shrimp, and other shelled invertebrates), shellfish, jellyfish and small fish.

Reproduction: every two years,adult female Sea Turtles return to the beach where they were born to lay up to 200 soft-shelled eggs in the sand. When the baby turtles hatch, they immediately head for the nearby water. Many young turtles are eaten by birds and other predators during this difficult trip. It has been estimated that only 1% of these hatchlings will reach adulthood. No one knows how the females find the beach where they were born.

Sea turtles and fragile ecosystems

Sea turtles play key roles in two ecosystems that are critical to them as well as to humans—the oceans and beaches/dunes. If sea turtles were to become extinct, the negative impact on beaches and the oceans would potentially be significant.

Life history

Sea turtles have an extraordinary sense of time and location. They are highly sensitive to the Earth's magnetic field and use it to navigate. The longevity of sea turtles has been speculated at 80 years.

Lizard

Lizards are reptiles of the order squamata, normally possessing four legs, external ear openings and movable eyelids. The adult length of species within the order range from a few centimeterto nearly three meters.

Diet

Lizards feed on a wide variety of foods including fruits and vegetation, insects, sm

all tetrapods, carrion and even (in the cases of large predator lizards) large prey such as deer.

Reproduction:

Most lizards lay eggs with tough, leathery shells. The eggs are laid in sand or rotting vegetation where they are concealed from predators but can be warmed by the sun. The American anoles lay a single egg each time. Many of the geckos lay two eggs. However, most lizard species lay several eggs at a time. Most lizards lay their eggs in a suitable nest and then abandon them.

Life history

Lizard life-history characteristics vary widely among species and populations. Lizard life histories are often phenotypically plastic, varying in response to temperature, food availability, and other environmental factors. Despite the importance of temperature to lizard ecology and physiology, its effects on life histories have received relatively little attention. Although life-history traits such as clutch size, egg size and the proportion of mature reproductive females varied little over 7 years in the intact population, manipulation of density to simulate decreased population density enhanced juvenile growth rate, age at first reproduction, frequency of female reproduction and size-specific clutch mass.

- In my opinion, the sea turtle is different than lizard because they have to living in the ocean. They also have different diet habit, like sea turtle eat the food are from sea and lizard eat the food from land. Also, they are both reptilian animal, but lizard walk or run very fast on the land, but sea turtle move very slow in the land.




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