Morphological sexual dimorphism isn’t completely recognized in green turtles until early adulthood.
Sexual dimorphism isn’t completely recognized in green turtles until early adulthood. As such, it is difficult to determine a green turtle’s sex until the animal is fully grown, at least 20 years old. Recently, however, researchers from the U.S. and Australia have developed a method to determine the sex of green sea turtles while the animals are still young via DNA and blood tests. There appears to be no easily recognizable difference in coloration between sexes.
Males and females differ morphologically by the length of their tail and cloacal openings. Female green sea turtles have smaller tails and a cloacal opening between the anus and tip of the tail. Male green turtles are slightly smaller in carapace length, have longer claws, and have longer tails where their reproductive organs are located. Their cloacal opening is located more posterior on the tail and past the end of their carapace.
Sources: (Frazier, 1971; Hersh, 2016; Hirth, 1997; Märzhäuser, 2018; Witzel, 1982)
Image: Jeremy Bishop