Turtles are reptiles with a hard cartilage shell that acts as a shield. They are either sea-dwelling or freshwater Testudines. Turtles are classified as members of kingdom Animalia, phylum Chordata, class Reptilia, and order Testudines. There are thirteen families in the order and more than 356 species. The families of turtles include the leatherback sea turtles, soft-shelled turtles, snapping turtles, and tortoises among others. The origin of turtles date back 220 million years ago making them older than both crocodiles and snakes. Unfortunately, most of the remaining species are considered highly endangered.
There are seven known species of sea turtles: loggerhead, green turtle, leatherback, hawksbill, Kemp's ridley, flatback, and olive ridley. Six of the turtles are found in the major oceans, but the flatback turtle is confined to the Western Indo-Pacific. They spend most of their lives in the sea with some diving to more than 3,000 feet, but the occasionally make long journeys to the shore of specific beaches to lay eggs. It is nearly impossible to estimate the exact number of sea turtles because of the limited time they spend on land, but the six species found in the American coast are all endangered. Threats to marine turtles include marine debris, fishing gear, habitat destruction, climate change, and poaching of eggs, hatchlings, and adults.
Size of Turtles
There is no exact estimate of the average size of a turtle considering that there are more than 360 different species. The leatherback is the largest sea; it can measure 4.5 to 5.25 feet and weigh anything between 600 to 1,500 lbs. A Galápagos tortoise in the San Diego Zoo grew to 6 feet and weighed 573 pounds. The alligator snapping turtle is the largest freshwater turtle. It grows to 2.5 feet and can weigh as much as 220 lbs. The largest softshell turtle is the Yangtze giant softshell turtle. It grows to about 3.6 feet and weighs about 309 pounds. The smallest species of turtle is the speckled Cape tortoise that grows to 3.1 inches and weighs 5 ounces.
Habitat of Turtles
Turtles are neither social nor territorial. They typically do not mind the presence of other turtles in their vicinity. They spend the day foraging for food and retreat to the nest after sunset to escape the nocturnal predators. They are generally noisy creatures, but the sounds they make depends on the situation. Some produce sounds similar to electric motors, belching humans, or barking dogs. The red-footed tortoise of South America goes to the extent of clucking like a chicken. They are highly adaptive and can be found in all continents except Antarctica. They are found in large numbers in the waters of Indonesia, the Galápagos Islands, Papua New Guinea, the Philippines, East Africa, Gulf of California and the reefs of the Caribbean.