As a means of sexing the turtle, this method is limited because you need to make sure that the turtle is fully grown. You may assume that a turtle is male due to a smaller size when it actually has more growing to do. There can be an overlap in size between a large male and a small female, so it’s not possible to predict the gender based on size alone.
A concave plastron allows for a male turtle to fit over a female’s shell during mating without rolling off. The female’s flatter plastron gives her more room internally in which to grow eggs.
The American box turtle: 90 percent of the time, male box turtles have red or orange irises while the female has brown or yellow ones. Also, the female has a tendency to have a higher-domed, more rounded shell, whereas the male has a lower shell with more of an oval or oblong appearance. Sun turtle: If the turtle’s underbelly has blue coloring, it’s a male. If the underbelly does not have blue coloring, it’s a female.
The Red-eared Slider species particularly shows a pronounced difference between the male and female front claws.
The female’s cloaca is rounder and more star-shaped than the male’s. It is found much closer to her body, at the base of her tail where it joins her body, almost disappearing into the shell. The male’s cloaca is longer and more slit-like. It is located in the last third of the tail, towards the tip.
Be aware that there is an overlap in normal sizes between male and female, so this can give you a hint, but it is not a foolproof way of sexing a turtle.
If all the signs point in one direction, then it’s more likely than not that you’ve determined the gender accurately. However, if the signs are mixed, you may wish to take your turtle to a vet to be certain. [7] X Research source If you’re not sure what conclusion to draw, wait until the turtle is older and try again. It is extremely difficult to sex a baby turtle. Be aware that you might have to wait years until your turtle is fully grown and you can determine the gender effectively.
