Also identified in English: Green turtle; French: Tortue verte; German: Suppenschildkröte; Spanish: Tortuga verde, Tortuga blanca.
Testudo mydas Linnaeus, 1758, Insulas Pelagi: Insulam Adscensionis (“Oceanic Islands: Ascension Island”). No subspecies are presently acknowledged. Nevertheless, some authors acknowledge the Pacific inexperienced turtle (additionally referred to as the black turtle) as a definite species; others take into account the Pacific inexperienced turtle a subspecies of Chelonia mydas. Results of DNA research don’t assist recognition of the Pacific turtle as distinct from different inexperienced seaturtles.
Large, reaching 60 in (152 cm) carapace size and 750 lb (340 kg) physique mass. The head is small and rounded anteriorly, and just one pair of elongated prefrontal scales is current on the highest of the pinnacle ahead of the eyes. The heart-shaped carapace is just weakly serrate posteriorly and has 4 pairs of pleural scutes, the primary pair of which doesn’t contact the nuchal scute. Twelve marginal scutes are sometimes current alongside all sides of the shell. Four inframarginal scutes (all missing pores) are current on every bridge between the marginal and the plastral scutes. The greenish coloration of the fats of this turtle is the supply of its widespread title.
All tropical and temperate seas.
Although inexperienced seaturtles enterprise into temperate seas, adults are discovered primarily within the tropics. These turtles could be discovered within the open sea, however they’re mostly seen in areas of shallow water with an abundance of submerged vegetation, particularly sea grass flats. Hatchlings are extra pelagic and infrequently are present in mats of sargassum.
Green seaturtles nest totally on tropical seashores and will migrate greater than 1,900 mi (3,000 km) between feeding and nesting areas. These turtles are identified to thermoregulate by basking on the water’s floor, however they’re the one marine turtle identified to go away the water to bask on land. One inhabitants within the Gulf of California is understood to hibernate underneath water by partially burying itself within the substrate.
FEEDING ECOLOGY AND DIET
Although it’s assumed that hatchlings and juveniles are primarily carnivorous, few information can be found. Adults are well-known to be virtually fully herbivorous, feeding totally on a number of genera of sea grasses in addition to on algae. Animal matter, resembling sponges, jellyfish, mollusks, crustaceans, sea urchins, and sea squirts, is sometimes ingested, some maybe secondarily whereas the turtle feeds on sea grasses. Feeding typically happens through the day.
The age at maturity of inexperienced seaturtles shouldn’t be definitively identified however is speculated to be between 20 and 30 years. Courtship and mating happen off the nesting seashores, and females might mate with a number of males. Courtship includes chasing, nuzzling, rubbing, sniffing, and biting the feminine. If the feminine is receptive, the male mounts her shell from behind and swings his a lot bigger tail underneath hers for intromission. Copulation might final a number of hours; one report describes a 52-hour mating. Mating might happen at or under the water’s floor. Females can retailer sperm, maybe for a number of years, so particular person eggs in the identical clutch might have totally different fathers.
There is appreciable variation within the timing of the inexperienced seaturtle nesting season, each regionally and globally. For instance, within the western Atlantic, nesting is often from March to October, with a peak from May to September. In the japanese Pacific, nesting might happen any time between February and January. Females exhibit appreciable constancy to their nesting seashores, and this trait accounts for slight genetic variations between separate nesting colonies. Females nest anyplace from the open sand above the excessive tide line to totally shaded areas simply inland from the seaside. Most nesting happens at evening. Nest development is comparable to that of the loggerhead seaturtle, besides that the inexperienced seaturtle digs the deepest physique pit of any cheloniid sea turtle (up to 20 in [50 cm]). Females lay as many as seven clutches in a season, normally at 12–14-day intervals, however laying two to 5 clutches is most typical. Clutch measurement is usually positively associated to the feminine’s measurement. Clutches vary from three to 238 eggs, though clutches of 100–120 eggs are typical. The leathery eggs are practically spherical and 1–2 in (2.5-5.eight cm), normally 1.4–1.6 in (3.5–Four cm) in diameter and weigh 1–2 oz (28–65 g, normally 35–50 g). Most females nest solely each two years, however cycles of 1 to 4 years are identified. Incubation sometimes requires 50–70 days however might take between 30 and 90 days, relying on nest temperature. Hatchlings emerge from their nests at evening and transfer instantly to the ocean. Green seaturtles exhibit temperature-dependent intercourse willpower. High temperatures produce largely females, and low temperatures produce largely males.
Green seaturtles are labeled as Endangered on the IUCN Red List. The Mediterranean subpopulation is listed as Critically Endangered.
SIGNIFICANCE TO HUMANS
Despite worldwide safety, inexperienced seaturtles and their eggs are nonetheless consumed by native peoples in lots of elements of the world. Many different human actions additionally improve mortality. Turtles are killed for sport, drown in shrimp or fish nets, and are wounded by boat propellers. Other turtles are killed by predators whose numbers have elevated due to human actions (e.g., raccoons, pigs, and canine). Nesting grounds are destroyed by resort and housing developments.