En peligro critico de extinción
Marine turtles are creatures that inhabit the seas and oceans and return to the beach to lay their eggs exclusively.
The Leatherback turtle, also known by the common names, Leatherback, Channel, or Leatherback (Dermochelys coriacea) is the largest of all living turtles, reaching a length of 2 meters and weighing over 600 kilos. A male individual weighed 916 kilos, but the turtles of this size are rare. Found in all tropical and subtropical seas and is the only species within the family Dermochelyidae.
This species has many unique features that distinguish largely on other sea turtles. Your metabolic rate is about 3 times higher than expected in a reptile of its size, which, together with its counter-current heat exchangers and large size allows to maintain a body temperature of up to 18 ° C above the surrounding water. Some scientists even believe that the leatherback has some ability to generate their own body heat, as a mammal, although reptiles are ectotherms or "cold blood", so they depend on the external temperature to regulate their own . However, we also can consider this species as gigantoterma.
The leatherback is the largest of all sea current and very different from the rest, both in appearance and in their physiology. It has a smooth shell and dark, with ridges that run from head to tail. This shell is composed of bony scutes, but is made of soft connective tissue (hence the name turtle leather is given at times). In the shell is not observed the breastplate or sharpening side edge, just a gentle curve that gives a semi-cylindrical appearance to the animal. This way, vaguely reminiscent of the musical instrument, is what has given the name of leatherback turtles.
The front flippers of leatherbacks are much longer than in all other turtles, both proportionately and in gross size. In adult individuals, the distance from end to end may be up to 270 centimeters.
The peak has developed a way to hook to help the leatherback turtle and jellyfish bite your throat is inward pointing barbs that help you swallow them.
Diet
Leatherbacks subsist on a diet of jellyfish. Due to the transparent nature of their prey, leatherbacks often suffocate eating pieces of plastic drift. Specimens have been found dead with plastic bags, pieces of hard plastic and fishing line in the stomach.
Mating
Leatherbacks mate at sea. Males never leave the water once they enter it as hatchlings. Females mate every three or four years, returning to the beaches where they were born to lay their eggs. A female may leave up to one hundred eggs in each deposition. The interval between a start and the next is about nine days. The first mating occurs after the turtle has completed ten years.
After encountering a female (who possibly exudes a pheromone to show their availability reproductive) the leatherback male uses head movements, touches with its snout, biting or movements of the fins to determine their responsiveness. Sea turtles are often difficult and sometimes dangerous maneuvers when trying to reproduce. The male has to mount the female from behind and getting on top in order to copulate, but sometimes the shells obstruct this process. Mating can also become dangerous when the male is so desperate for that mate spends too much time under water, and after the encounter with the female, until another time without breathing. Fertilization is internal, and it is normal that several males mate with one female. This behavior may have evolved to insure against male infertility, removing excess low-quality sperm and allowing the female to select the best, and increase the genetic variability of offspring. However, studies have shown that polyandry in marine turtles actually reduces fertilization success.
Cell division begins a few hours after fertilization, but development is suspended during the gastrula stage to move and wrap embryonic cells until the eggs are deposited. The development will resume soon, but the embryos remain extremely susceptible to die in their nests by movement of the egg until the membranes are fully developed during the first 20-25 days of incubation, when the structural differentiation of body and organs (organogenesis) continues.
Nesting beaches are covered with soft sand and having an area of shallow coastal water. This is due to their soft shells are easily damaged by the hard rock. This is a source of vulnerability for the turtles because these beaches are likely to erode. Females dig a nest on the high tide line with their fins and only make the stools at night because the heat of the day increases the body temperature to be maintained above the limit and it may be dangerous. Then begin to lay eggs, producing about 110 of which 70 are longer and fertile, and the remaining 40 smaller and sterile. These 40 remaining eggs to serve as buffers and other protection and are deposited with the sole purpose being the only species of turtle that does this. The female covers the nest carefully, making sure to camouflage from predators with a layer of sand.
The eggs are incubated for 60 days. Like other reptiles, the temperature of the nest determines the sex of the offspring.
The eggs hatch while still under the sand and all together as one, after dark, hatchlings dig their way to the surface and continue their brand to the sea. Once the hatchlings reach the ocean would not normally be seen again until they reach maturity. Very few of them survive this mysterious period to become adults. Many are eaten by birds and even other reptiles before they have the opportunity to dive into the water. When the city lights are visible from the nesting area, leatherback hatchlings are attracted by the lights and away from the sea. Many of these calves are run over by traffic or die in other ways.
Leatherbacks nest in February and August depending on the area, and its preferred beaches of the river mouth Marowijne in Guyana, Bigi Santi (Surinam), Isla de Culebra (Puerto Rico), Yalimapo (French Guyana), Terenganú (Malaysia) Mexiquillo in Mexico in Costa Rica from the Panama border to the border with Nicaragua, focusing on Tortuguero and Gandoca. Playa Grande and the Pacific of Costa Rica. In Terenganú decreases each year due to human pressure, to the extent that there have been times when they have not been leatherbacks come to Malaysia, despite being historically the Asian area most frequented by these animals.
Distribution and habitat
Leatherbacks live in almost all oceans of the world, venturing farther north or south than other sea turtles because of their peculiar system of regulating body temperature.
In the summer, leatherbacks are more common in the area from the Gulf of Maine north to Florida in the south. Have been observed also in the northern Gulf of St. Lawrence, Canada. The Pacific leatherbacks are more often seen in the Hawaiian Islands, which are known to congregate in the north of the archipelago. When winter approaches heading south, the Caribbean Sea and the coastal areas of Central and South America and Africa, where the turtles are from Europe. In this last, thanks to the Gulf Stream, they venture further north during the summer months, and have come to be seen sporadically off the coast of Norway and the Baltic Sea. The populations of East Asia migrate to the coasts of Indonesia and Australia and the Indian Ocean. Thanks to recapture, it is known that this species of turtle performs transoceanic migrations, such individuals tagged in Gabon, Africa, have been recaptured in south-western Atlantic Ocean.
The turtles prefer deep water but are grouped more often when they arrive at Earth. In the summer are often seen basking near the surface, particularly in the estuary of Long Island, where they have been injured after colliding sometimes with boat propellers.
Threats and Conservation
The leatherback turtle has been classified as endangered throughout its distribution since 1970. You will be also included in the Convention on International Trade in Endangered Species (CITES). This makes it illegal to injure or kill the turtles.
The adult leatherback turtles are large animals, not particularly vulnerable to predators. The eggs and hatchlings, however, are most at risk of all. Birds, dogs and other opportunistic predators have been seen digging nests and eating eggs. The young are also vulnerable in the way from the nest to the sea. Once you enter the water are prey to many new predators and very few survive to adulthood.
Human activity threatens the leatherback turtles in many ways. Believing them to be forgotten, eggs are collected by people in Puerto Rico, the surrounding islands and probably elsewhere. The remodeling of the beaches can disrupt or destroy the particular type of habitat needed turtles nesting leather, and the lights of progress can cause hatchlings to move away from the sea instead of toward it. Human use of beaches can destroy nests and eggs laid or buried too deep for the hatchlings to emerge. Finally, humans can harm nesting females out of curiosity.
While adults are at sea its greatest threat comes from humans altogether. The intakes of plastics, rubber, tar, motor oil and other synthetic products can kill an adult Leatherback or damage seriously. Many have been injured by collisions with boats, especially in shallow water. The equipment associated with commercial fishing, including wires, nets, ropes and cables can entangle and drown adult turtles. Although the "Turtle Exclusion Devices" are required for networks, often fail when it comes to allowing an animal the size of an adult leatherback turtle escape from them. NOAA estimates that about 640 adult leatherback turtles are killed each year by commercial fishing companies.
The networks are set deliberately to catch other species of sea turtles in some areas of Puerto Rico. Although not intended for leatherback turtles, some are occasionally caught. This practice is illegal, but is ongoing. In New Guinea, leatherbacks are hunted as food regularly.
But there is hope in many places local organizations and governments have initiated programs concienticiacion, education and protection and conservation projects involving coastal communities and creating a culture of conservation of natural resources.
Condition
In critically endangered
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La abundante vegetación de la selva costera conforman un corredor biológico de gran importación para la vida silvestre del refugio, un remanente de bosque primario mayoritariamente arboles de cativo, almendro, caobilla son verdaderas joyas naturales, arbustos, heliconias (produce una flor utilizada para arreglos florales) manglares (mangle rojo, el mangle caballero, mangle salado, mangle blanco y el mangle botón o botoncillo) yolillales y pantanos herbáceos. Cocoteros, papaturros o uvas de playa. En su área marina hay lechos marinos formados por el zacate de tortuga (muy abundante, a poca profundidad), el zacate de manatí y varias especies de algas.
