Externally this can only be done when turtles reach maturity. A male’s tail at this point extends out further than the back flippers, and is maybe 40 to 50 cm long. The female’s tail is much shorter, only 5-15 cm long.
The problem is, when the turtles are immature, there is no difference. So, a large turtle with a short tail could be an immature turtle or a mature female, while a long-tailed turtle is definitely a male. Scientists dissect baby turtles to determine their sex but only if necessary, and can use micro-surgery with a laprascope to determine gender in larger turtles.












