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Is My Yellow-Bellied Slider Turtle Male Or Female?

Thinking of getting a yellow-bellied slider turtle? Or maybe you’ve just adopted one, but the previous owner or shop didn’t mention whether it’s a boy or a girl? You’re probably wondering about the differences between a male vs female yellow-bellied slider turtle.

Although it often takes some practice to learn to reliably tell the males from the females, it is possible to sex Trachemys turtles like the yellow-bellied slider visually. Let’s find out how!

Male or female: does it matter?

In terms of whether one is better than the other? No, they both make good pets for the right owner.

This being said, there are a bunch of good reasons to want to know whether your yellow-bellied slider turtle is male or female. It’s not just about satisfying your natural curiosity, but it also helps you understand your turtle better.

Here are some reasons to want to know the sex of your turtle:

  • It helps you understand certain behaviors, like when a male becomes territorial or a female starts acting nesty.
  • It allows you to figure out which of your turtles can live together. Multiple males can sometimes get a little too aggressive if there are also ladies around.
  • It enables you to monitor your turtle for problems that mostly occur in females, like potentially fatal egg-binding.
  • It lets you pair up turtles in case you want to try your hand at breeding (although for most hobbyists, it’s better to refrain from doing so).

Is my yellow-bellied slider turtle male or female?

As we mentioned, yellow-bellied slider turtles (Trachemys scripta scripta) are sexually dimorphic, meaning you can tell the difference between males and females visually. There are various indicators, with the most obvious one being their claws.

Here’s how you tell the difference between a male vs female yellow-bellied slider turtle:


Ever seen those funny videos of a turtle doing a sort of strange dance at another turtle, waving its claws in front of the other’s face? That’s actually their mating dance. The females judge the performances in order to pick which male to mate with.

Because female yellow-bellied sliders are apparently attracted to a nice manicure, the boys tend to have much longer nails. The claws on the females are relatively stubby.

Split image showing female yellow-bellied slider turtle (top) vs male (bottom), with arrows pointing out the difference in their claw length.


If you happen to know that the turtle in question is an adult (at least around 8 years old), you can have a look at its size in order to help you determine whether it’s male or female.

As with many animals, female turtles in general are larger than the males. Yellow-bellied sliders are no exception. Males usually don’t surpass 10″ in length even as fully-grown adults. Female yellow-bellies can reach up to 14″ in length.

According to researchers, the evolutionary reason for the size difference is two-fold:

  • Smaller males means they’re more nimble and can more easily move around in search of females.
  • Larger females means they can carry more eggs and are more efficient at reproducing.

Plastron shape

The plastron, which is the bottom of a turtle’s shell, is shaped differently in male vs female yellow-bellied slider turtles. If you can pick up the turtle in question to look at its belly, that should provide a good clue.

With turtles, when the time comes to reproduce, it’s the male that mounts the female. To make this easier, males have a slightly concave plastron, i.e. it curves inward a little. The plastron on a female is flat as usual.

Tail shape

Another great indicator of sex in slider turtles is their tail. In males, the tail tends to be long and thick. If the turtle you’re looking at has a chunky tail, it’s probably a boy.

Females have shorter and thinner tails.

Cloaca positioning

Speaking of the tail, it offers up another clue, although you’d have to be able to handle the turtle in question to be able to see it. Turtles have a cloaca, which is basically a general entry and exit for all their bodily functions: poop, pee, mating, eggs.

In females, the cloaca is situated right at the base of their tail. In males, it’s located away from the base, about halfway or more towards the tip.

Did you know? When trying to figure out whether your yellow-bellied slider is male or female, it’s important to remember that age is an important factor. It can be difficult to sex a young turtle and almost impossible to sex a baby. Things become much clearer at around the 5-year mark. Patience is key when it comes to anything turtle-related!

Male yellow-bellied slider turtle (Trachemys scripta scripta)
QUIZ TIME: Based on what we’ve learned, do you think this yellow-bellied slider turtle is male or female? Scroll down to the end of this post to find the answer.

Frequently asked questions

Can you keep male and female yellow-bellied sliders together?

Sure, though remember that turtles aren’t really good candidates for spaying or neutering. Unless you want an army of yellow-bellies, you’ll have to remove any eggs the female lays.

Can you keep multiple male yellow-bellied sliders together?

If there are females present, this can turn into a bit of an aggressive mess unless there’s a LOT of space available. Even without any females, they can still be territorial, so have a plan B in place in case you need to separate them.

Can you keep multiple female yellow-bellied sliders together?

This usually works out a bit better than multiple males. Just make sure there’s plenty of space. Do still keep an eye out for any squabbles, and don’t combine turtles of very different sizes.

So, is your yellow-bellied slider turtle male or female? With the help of this article, you’ve hopefully figured out whether you’ve got a boy or girl on your hands!

By the way, if you’re having trouble figuring it out, others will be able to help. Try posting some clear photos in a turtle forum or Facebook group, for example. Or ask your vet when you take the turt in for a check-up! They’ll definitely be able to tell you whether it’s a boy or a girl.

If you still have more questions, or if you want to share more tips for sexing a yellow-bellied slider, don’t hesitate to leave a comment below.

QUIZ ANSWER: The turtle shown is a male. Note his long claws!

Sources & further reading

Berry, J. F., & Shine, R. (1980). Sexual size dimorphism and sexual selection in turtles (Order Testudines). Oecologia, 44, 185-191.

Photo of author

Marijke Puts

Hey! I'm Marijke, FantaSEA's resident blog writer. I'm a full-time pop science author, part-time PADI diver and snorkeler, and have been keeping fish since I was a kid. When I'm not writing fish care guides, you can usually find me underwater or trying to figure out how to fit more tanks into my house.

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