The loggerhead sea turtle is an oceanic turtle of the family Cheloniidae. It is called loggerhead because of its large head. It is the largest hard-shelled turtle in the world. There are mainly two subspecies of loggerhead turtles, Caretta caretta and Caretta caretta gigas. This oceanic turtle is distributed across the world, and its habitats encompasses three ecosystems. Physical Appearance The adult loggerhead can grow up to a length of 213 cm. The adult, fully grown turtle can weigh about 135 kg. The most distinguishing feature of this turtle is its reddish-brown colored shell, that is divided into two sections - plastron and carapace. Its skin color can range from yellow to brown, while the underside is usually pale yellow in color. The female turtle cannot be distinguished from the male, until both mature and become adults. The adult male usually has a thicker tail and shorter plastron than its female counterpart. The carapace of the male is also wider, but less domed, as compared to the female. Furthermore, the male usually possesses a wider head than the female. A loggerhead turtle cannot withdraw its head into the shell, unlike many other turtles. This turtle attains sexual maturity between 17 to 33 years of age. The average life span of this sea turtle is approximately 47 to 67 years. Habitat and Range As has been mentioned already, loggerhead turtles are distributed across the world. They can be found in Indian, Atlantic, and Pacific oceans. The adult turtle spends a major part of its life in saltwater, except for the female, who comes ashore for a brief period to lay eggs. Shallow coastal water, salt marshes, lagoons, reefs, and estuaries are the most common habitats of this turtle. Many of these turtles can also be found in open seas and bays. However, at different stages of their life cycle, loggerhead turtles can be found in three different ecosystems, known as terrestrial zone, oceanic zone, and neritic zone. The life of a loggerhead turtle begins in the terrestrial zone, as the female turtle comes ashore for a short period of time to construct a nest and lay her eggs. The female usually deposits eggs in the ocean beaches and coastline. Narrow, steeply-sloped, and coarse-grained beaches are usually preferred by the female for making a nest. Soon after birth, the hatchlings move towards the sea. They are usually swept by the water, though a few hatchlings do get caught up in the seaweeds near the shore. Such hatchlings may need to spend several days near the shore. But others can quickly reach the open water of the sea. The hatchlings continue to swim for several days. The juvenile turtles then settle down along the continental shelf, or near the shore and shallow estuaries. These are the areas where one can find large masses of seaweeds like Sargassum algae. These are the habitats for the juvenile turtles till they mature. Along with juvenile loggerheads, these habitats are shared by many other organisms like ants, aphids, beetles, flies, larvae of small crabs, barnacles, hydrozoan colonies, and fish like, tuna, dolphin, and amberjack. In the Pacific ocean, loggerhead turtles can be found from Alaska to Chile. The California coastline is another area, where loggerheads can be widely spotted. In Atlantic ocean, these turtles can be found throughout the Gulf of Mexico, and from Canadian island to Argentina. Loggerheads are omnivorous and they consume the bottom-dwelling invertebrates, like decapods, gastropods, and bivalves. In fact, their list of prey is quite a long one that can include, algae, corals, polychaete worms, cephalopods, barnacles, sea urchins, and starfish. They also eat jellyfish, floating mollusks, and flying fish during the long migration period. The loggerhead sea turtle is considered an endangered species. The International Union for Conservation of Nature (IUCN) has taken several measures to protect this animal. The use of untended fishing gears, and the lack of suitable beaches for nesting are the greatest threats to this animal. Since nesting beaches are spread all over the world, the success of the various conservation efforts depends on international cooperation.