How to Tell If a Terrapin Is Male or Female

A terrapin is a variety of North American aquatic turtle. Terrapins are commonly sold in pet stores and make intriguing pets. It helps to know if your terrapin is male or female if you plan to keep more than one so you don't end up with unwanted baby turtles. Females grow to be quite a bit larger than males, so this can also assist you in preparing the proper housing for your pet terrapin. A few differences between the sexes can help you tell if your terrapin is male or female.

Instructions

    • 1

      Gently turn your terrapin over onto its back and take note of the bottom half of its shell, also called a plastron. In a female, the plastron will be either flat or convex. In a male, it will appear concave.

    • 2

      Observe the differences between the tails in different terrapins. The tails of females are wider, while those of males are much thinner.

    • 3

      Inspect the underside of the tail. The opening found on the underside of the tail from which the terrapin lays eggs, excretes feces or urine and also leads to the sexual organs is called the cloaca. The cloaca of the female is closer to the body than that of the male, which is closer to the tip of the tail.

    • 4

      Note the size of your terrapin at adulthood. Males can grow to be approximately 7 inches in length, whereas the female terrapin can grow to approximately 12 inches in length, nearly twice the size of the male.

    • 5

      Compare the claws. Claws of the male are much larger than those of the female.