Differences in Male & Female Red-Eared Turtles

Red-eared turtles are amusing pets with charming courtship rituals. They recognize owners and swim to the sides of tanks to greet them. Differences in male and female red-eared turtles are difficult to spot until they mature. As it's illegal to commercially sell immature turtles under 4 inches long, your "male" pet from the store might surprise you in mating season by laying eggs.

  1. Tails

    • Red-eared turtles are also known as sliders and red-eared-sliders, or RES, to enthusiasts.

      The differences between tails in the male and female of this species are one of the main ways to tell them apart. Males possess larger and wider tails than females. The opening on male tails, known as the cloaca, is located three-quarters of the way down their tails from the shell, or carapace, to the tip of the tail. Females have thinner tails with their opening nearer the shell.

    Shells

    • The bottom half of a turtle's shell is called the plastron. To determine if you have a male or female turtle, gently turn it over and examine the plastron, since their sizes differ between male and female red-eared turtles. Females typically have plastrons that curve outwards, to allow the female more room to carry eggs. Male plastrons curve inwards and allow a better fit when the male takes up the mating position on top of the female.

    Claws

    • Claw size is another way to determine if your pet is a male or female red-eared turtle. Both sexes have a shorter claws on their back legs. Only the male has longer claws on his front legs. Males use these longer claws to get a good grip on the female during mating. They also feature in courtship rituals, when the male stretches out his front legs and vibrates his claws while stroking her cheeks and neck. If she is not ready for mating, she responds by running away or fighting him off. Once she is ready, she'll stroke his front claws.

    Physical Maturity

    • Red-eared turtles living in the wild take between two and seven years to reach maturity. Generally females are larger than males, measuring from six to seven inches long, and mature at between 5 and 7 years old. Adult male turtles reach maturity after two to five years, when they are approximately four inches long. Captive turtles can reach maturity and be ready to breed when they are between 2 and 5 years old, because their diets in captivity are more nutritious.