Green Sea Turtle

The green sea turtle, scientifically known as Chelonia mydas, is a large species of sea turtle that belongs to the family Cheloniidae. It is the lone species in the genus Chelonia. This species can be found in tropical and subtropical seas worldwide, with distinct populations in the Atlantic and 🌊 Pacific Oceans, as well as the 🌊 Indian Ocean. Despite its name, the green sea turtle's carapace color varies from olive to black. The name actually comes from the green fat found beneath its carapace.

The Chelonia mydas has a flattened body covered by a teardrop-shaped carapace and is equipped with large, paddle-like flippers. While it is typically lightly colored, some of the eastern Pacific populations can have almost black carapaces. Unlike other sea turtles, such as the hawksbill sea turtle, the green sea turtle primarily consumes vegetation and is mostly herbivorous. Adult green sea turtles inhabit shallow lagoons and feed on various species of seagrasses, biting off the tips of the blades to promote grass health.

Green sea turtles, like other sea turtle species, undertake long migrations between feeding grounds and hatching beaches. Many islands are known as Turtle Island due to the presence of green sea turtles nesting on their beaches. Female turtles come ashore on these beaches at night to dig nests and lay eggs. Reproduction occurs every 2 or 3 years, with each clutch containing 100 to 150 eggs laid at intervals of 10-15 days. The incubation period lasts for 45-60 days. It is observed that mostly males hatch from nests with temperatures below 30°C, while mostly females hatch from nests with temperatures above 30°C. Hatchlings emerge and make their way to the water. If they survive to maturity, green sea turtles can live up to 90 years in the wild. Unfortunately, the IUCN and CITES have classified Chelonia mydas as an endangered species. It is protected from exploitation in most countries, and it is illegal to collect, harm, or kill them. Many countries have also implemented laws and ordinances to safeguard nesting areas. However, human activities such as hunting for food, pollution, and habitat loss due to development continue to threaten the survival of these turtles.

In terms of physical appearance, Chelonia mydas resembles other sea turtles. It has a dorsoventrally flattened body, a short neck with a beaked head, and paddle-like arms ideal for swimming. Adult green turtles can grow up to 1.5 meters (5 feet) in length and weigh between 68-190 kg (150-419 lbs), with exceptional specimens weighing even more. The green turtle is distinct from other members of its family in several anatomical characteristics. Its snout is short and the beak is unhooked, unlike the hawksbill turtle. Unlike other turtles, the green turtle cannot retract its neck. It has a denticulated edge on the sheath of its upper jaw and stronger, serrated denticulation on its lower jaw. Its carapace consists of five central scutes and four pairs of lateral scutes. Underneath, it has four pairs of inframarginal scutes.

The carapace of the green turtle displays different color patterns that change over time. Hatchlings primarily have black carapaces and light-colored plastrons. Juveniles develop dark brown to olive carapaces, while mature adults have entirely brown, spotted, or marbled shells with variegated rays. The plastron of the turtle is yellow in color. The limbs of Chelonia mydas are dark-colored and lined with yellow, often featuring a prominent dark brown spot in the center.

The habitat of green sea turtles encompasses three different types, depending on their life stage. They lay eggs on beaches, while mature turtles spend most of their time in shallow coastlines with abundant seagrass beds. They can be found in bays, lagoons, and shoals with thriving seagrass meadows. These turtles often migrate between their feeding and nesting grounds, with their distribution limited by ocean temperatures below 7 to 10 degrees Celsius. Along continental and island coastlines, green sea turtles inhabit protected shores and shallow bays, including coral reefs, salt marshes, and seagrass beds. These habitats provide food sources such as algae, seaweed, grass vegetation, and wetland plants. Green sea turtles typically swim at speeds of 2.5-3 km/h (1.6-1.9 mph).

The diet of green turtles evolves as they grow older. Juveniles are carnivorous, consuming fish, their eggs, and a variety of marine invertebrates. However, as they mature, they become omnivorous. The green sea turtle has a unique feeding technique where it trims the tops of seagrass blades while leaving the roots intact, promoting the growth and health of the seagrass beds. They also consume other vegetation such as algae, leaves, tree bark, and crustaceans. Despite their slow growth rate, green sea turtles have adapted to convert their body fats into green hues due to the consumed vegetation. This dietary shift has led to changes in the turtle's skull morphology, with serrated jaws helping them chew algae and sea grasses.

Adult Chelonia mydas face threats from human activities and larger predators, such as sharks. Tiger sharks, in particular, hunt adult green sea turtles in Hawaiian waters. The tiger shark is the main predator of the green turtle, especially near their nesting beaches where they are vulnerable. Juveniles and hatchlings face a greater number of predators, including crabs, small marine mammals, shorebirds,