Leatherback Turtle/ All About Leatherback Sea Turtle

 Leatherback Turtle/ All About Leatherback Sea Turtle 

The leatherback turtle also called leathery turtle. The leatherback turtle is the largest sea turtle species on the earth. It is the fourth-heaviest reptile after crocodilians. The scientific name is Dermochelys coriacea and it is only extant species in genus Dermochelys. This species belongs to family Dermochelyidae. Unlike other sea turtle species, leatherback turtle has no bony carapace or shell but it has firm rubbery skin and oily flesh cover. Leatherback turtle gets its common name from its leathery texture and also for its carapace. Once they were called leathery turtles and trunk turtle. Leatherback turtle evolvedover 110 million years ago during the age of the dinosaurs

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Description of Leatherback Turtle 

Leatherback turtle, the largest species of sea turtle on Earth. It has no bony carapace that the other species of sea turtles have. Its bluish-black carapace is flexible and leathery with white or pale spots but its plastron is white or black in color, marked by five ridges. It has seven ridges which are called “keels” that rise from its carapace which crossing the length of the turtle’s back. Under its carapace, has a layer of fat called blubber and also has thousands of tiny bone plates that make the the carapace hard and strong. 

Leatherback turtle has no teeth but its scissor-like delicate jaws with backward spines in its throat help it to eat its food. Their forelimbs are flattened and can grow up to 2.7m that help them to swim in the open ocean. The leatherback turtle’s flippers are the largest among all the sea turtles. 

Leatherback turtle can grow up to 7feet and weight can reach 1500 pound but in one freak case a specimen was found about 2019 pound. The hatchling, when freshly hatched, their average weight is around 46gm and length can be 62.2mm. 

Leatherback turtle can maintain warm body temperature in cold water. Its huge size and a thick layer of fat or blubber help them to keep its body warm. Leatherback turtles can reduce their heartbeat and alter their swimming pattern to reduce energy expenditure and amount of oxygen used. These two sets of adaptations help them to keep their body temperature as much as 18°C warmer than surrounding waters in which they swim. They constant swim and spend only 0.1% of the day resting. Their swimming activity create muscle-derived heat that also help them to keep their bodies warm. Their higher metabolism and huge muscles create a lot of heat also. 

Generally, leatherback turtle can dive over 100 miles but it was recorded that it can dive 3937 feet. Its large flexible lungs help them stay submerged in water for hours, and its carapace is able to withstand the pressure of water. It can slow it heartbeats that helps it to conserve oxygen and energy. In ocean water, they can move at   the speed of 35.28 km/hr. When the leatherback turtle dives deep, it carries twice the amount of oxygen in its blood that redirect to the brain and heart, so that its vital organs always get oxygen. 

Leatherback turtle flat corneas and nearly spherical lens which are suited to see the ocean surface under water. In its eyes, has cone cells that detect colored light while rod cells detect any movement in dim light. Their large pupils of eyes help them to locate their prey.  

Leatherback turtle ears are not visible on the outside of its head and also covered with a protective layer of skin which is called “tympanum” and under the tympanum, has a layer of fat. Leatherback has a strong sense of smell which helps them to locate prey in murky or dark water. It is thought that female leatherback turtles find their way back to their natal beach by using their sense of smell. 

Reproduction of Leatherback Turtle 

Male leatherback turtles usually mate every year in the sea water while female turtles mate every 2 to 3 years. One single female usually mate with many male turtles. Male leatherback turtles never leave the water but female turtles nest on land. Female leatherback turtles migrate thousands of miles, averaging 3,700 miles each way to reach the beach where once they were born, which is called “natal homing”. They use the magnetic field of the Earth to differentiate their global position by latitude and longitude. Their internal compass helps them to return to the specific location. Another possibility is that a distinctive smell of their home beach, helps them to reach their natal beach or birth beach. 

After reaching its home beach, female leatherback turtle first clears the area of any debris with her front flippers and throws sand backward and dig a pit by using its hind flippers. This egg- chamber is about 80cm deep. Then at night, she lays 80 eggs in batches of 2 to 3 times at a time in the pit. The eggs are soft and the size of a ping pong ball. After laying eggs, she fills the hole with sand by using their flipper, now it leaves the nesting ground. After incubate for 60 days the eggs start to hatch. The temperature in the nest affects the sex-determination. The temperature of the nesting sites is above 30° Celsius produce females and below 30° Celsius produce males. 

Where do Leatherback Turtles Live? 

Leatherback turtles live in the tropic and temperate waters of the Atlantic Ocean, Pacific Ocean and Indian Ocean and also in Mediterranean Sea. The Leatherback turtle are found as far north as Alaska and Norway and as far south as Cape Agulhas in Africa and southernmost tip of New Zealand and also found in Arctic Circle. Leatherback turtles live in cold water where an abundance of jellyfish because they mainly eat jellyfish. Off the Atlantic coast of Canada, Leatherback turtles are found in the Gulf of Saint, Lawrence, Newfoundland and Labrador. 

Their known nest on Suriname, Guyana, French Guiana in South America, Barbuda and Antigua and Trinidad and Tobago in the Caribbean and Gabon in Central Africa. Their nesting grounds are also found on the Eastern Coast of Florida and the beaches of Gandoca and Parismina in the Costa Rica. 

In Indian Ocean, Leatherback turtles live in Sri Lanka and Nicobar Islands. The nesting ground of Pacific leatherback turtles are found in Papua, Indonesia and Solomon Islands, Mexico, El Salvador, Nicaragua, Costa Rica, Panama. They are also found along the western coast of South America, coast of California, Oregon, Washington. The Leatherback turtles also visit the beaches of British Columbia. They live in open ocean and swim from Jeen Womom beach of Tambruw Regency in West Papua to the US in 20,000km for foraging. 

What do Leatherback Turtles Eat? 

Leatherback turtles are carnivore and eat mainly jellyfish or gelatinous prey and sea squirts so they are also referred to as gelatinivores. Their jaws are week and flexible so they cannot eat hard-bodied prey. This turtle eats soft-bodied invertebrates such as tunicates and sea squirts, fish, crustaceans, seaweeds. They have sharp, backward pointing spines, one on the upper jaw and one on the lower, jaw that help them to pierce, swallow the jellyfish and prevent the prey from escaping from their mouth. 

Threats to the Leatherback Turtles 

in Canada Leatherback turtles are listed as endangered species and in the United States, they are declared as endangered species.  

Leatherbacks face various dangers at every stage of their lives. It is estimated that only a few in a thousand leatherback hatchlings survive to adulthood. Leatherback turtle’s population have reduced in the past few decades due to human’s demand for their meat, skin, eggs and shells. bycatch in commercial fishing gear, illegal trade, consumption, and climate change are the main reasons for their threat. They are killed for medicine and religious ceremonies. 

Under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), international trading of the leatherback turtles and their parts is prohibited but yet illegal trafficking persists. Vehicle traffic on beaches, uncontrolled coastal development and other human activities are the major causes of damage and destruction of hawksbill sea turtle nesting beaches worldwide. Vehicle traffic on the beaches makes the sand harder which make it impossible for female leatherback turtles to dig nests. Hatchlings disoriented by lights from roads and buildings may not reach the water and face a higher risk of dehydration and predation during this critical period. 

Leatherback sea turtles are among the highest migratory animals on Earth. When they migrate, they entangle in fishing gear. Leatherback turtles prefer to eat jellyfish. When they see plastic bags floating on the water, they are attracted to them, resemble jellyfish and eat plastic bags that often kill them. 

How many leatherback turtles are left in the world? 

The Pacific leatherback turtle are the world's most endangered turtle and only 2,300 adult females now remain and in North Atlantic, a range of 34,000 to 94,000 adult leatherbacks are left. 

Do leatherback turtles bite? 

Leatherback turtles are not aggressive but when they feel danger or frighten, they can bite a human. Their bites are usually very painful because they have sharp, backward pointing spines, one on the upper jaw and one on the lower, jaw which creates severe skin bruises and can break the bones. 

Where are leatherback turtles found? 

Leatherback turtles live in the tropic and temperate waters of the Atlantic Ocean, Pacific Ocean and Indian Ocean and also in Mediterranean Sea. The Leatherback turtle are found as far north as Alaska and Norway and as far south as Cape Agulhas in Africa and southernmost tip of New Zealand and also found in Arctic Circle.  

Off the Atlantic coast of Canada, Leatherback turtles are found in the Gulf of Saint, Lawrence, Newfoundland and Labrador. 

In Indian Ocean, Leatherback turtles live in Sri Lanka and Nicobar Islands. They also forage along the coast of California, Oregon, Washington; western coast of South America. 

How long do leatherback turtles live? 

Leatherback turtles can reach maturity at the age of 16 years old. They can live up to 30 to 45 years.