Male Vs. Female Red-Eared Slider: 7 Differences

The information is current and up-to-date in accordance with the latest veterinarian research.

Sharing is caring!

Red-eared sliders are an excellent choice as pets. If you have a red-eared slider turtle, you are probably confused about its gender. Male and female sliders look quite similar. However, there are some differences that can help you identify their gender. 

Mature female red-ear sliders are larger than their same-age male sliders. Besides, you can see visible differences in shell shape, claw, color, and tail size. 

If you want to learn how to differentiate between male and female red-eared sliders, then this article is for you. Before that, let us understand why it is important to identify the gender of your turtle. 

Why Is Identifying the Gender of A Red-Eared Slider Important?

Many people get red-eared slider turtles without considering their genders. But knowing the gender of your pet is important for many reasons. It is not only necessary for naming but also for biological reasons. 

Here are the reasons you should identify your red-eared slider’s gender:

Giving a Name

When you have turtles as pets, you expect them to live a long life, right? Red-eared sliders can live 20 to 30 years. Hence, naming them is a logical step. 

Many people prefer to give gender-specific names to their pets. So, knowing the gender of your sliders will help you name them according to their gender. 

Breeding and Egg Laying 

There might be a time when you want more red-eared sliders. Instead of buying new ones, why not breed from your red-eared sliders? Thus, you will need to know if you have male and female turtles. Besides, the mature female red-eared turtle will require extra space and care for laying eggs. 

Creating a Friendly Space 

When you want to have multiple red-eared sliders in one tank, keep a balanced number of male and female turtles for a friendly environment. Thus, knowing your pet’s gender is important.

See also  How Long Should A Red Eared Slider Bask?

Male red-eared sliders often behave aggressively towards each other. If you have multiple males, provide a spacious tank with enough resting place to avoid territorial conflict. 

Turtle Gender Identification Chart

turtle gender identification

For a printable version of this amazing visual chart, click here!

When Does The Gender Difference Become Visible?

It is difficult to determine the sex of baby red-eared sliders because the male and female hatchlings look the same. Only the breeders can tell the gender. So, if you are not the breeder, you have to wait a few years to see the difference.

When male and female red-eared sliders become sexually mature, it becomes easier to see the difference. Generally, adult male red-ear sliders can be 7 to 9 inches (17.78-22.86 cm) long, and female red-eared sliders get 10 to 12 inches (25.4-30.4 cm). 

However, the differences start to show when the male turtles become 4 inches in length, which takes 2 to 5 years and female turtles reach 5 to 7 inches in 5 to 7 years. 

7 Differences between Male and Female Red-Eared Slider Turtles

Physical AttributesMalesFemales
Claw LengthLarge front clawsShort front claws
Size7 to 9 inches10 to 12 inches
The Shape of the ShellsPlastron is ConcaveSmooth and flat plastron
TailLong and thickShort and thin
Cloaca PositionNear the end of the tailClose to the edge of the shell
ColorDarker color, faded yellow stripesLighter color with visible marking

Let us suppose you have red-eared sliders that are 4 inches or above. Then you can already see some physical differences in them. Here are the most obvious differences in male vs. female Red Eared Sliders:

1. Length of the Claw

One of the earliest physical differences between a male and female red-eared slider is the length of their front claws. The male sliders start to grow their front nails when they reach 2 to 3 years, the time of their sexual maturity. Their claws are long and sharper than the claws of female sliders, even at a very young age. 

The male turtles use their claws to coax the female turtles to breed with them. When they get ready to mate, they will come face to face with a female turtle and tickle their shells. These long claws are also used to hold on to the female slider’s shell while mating. 

On the other hand, female sliders have thick and shorter front claws. Their back claws are slightly larger than their front claws, as they need them to dig the soil to lay eggs. 

See also  Why Do Red Eared Sliders Climb On Each Other?

2. The Size of the Sliders

When the red-eared sliders reach their maturity, the biggest clue about their sex is their size. Female red-siders are larger compared to their same-age males. 

As mentioned above, a mature male slider gets 7 to 9 inches long while the female can reach 10 to 12 inches long. On average, a 10-inch long female slider can weigh about 7 pounds and a 7-inch male slider weighs only 4 pounds. 

Remember, this difference is only valid for same-age red-ear sliders. Also, some males can grow beyond their average size, and some females can be below their typical length. So, it is better not to depend only on the shell size to determine the sex of a red-eared slider. 

3. Shape of the Shells

Apart from the size, there is a difference in the shell shape of the male and female red-eared sliders. The difference is actually in the plastrons (the stomach of the shells. 

To see the difference, pick up one of your red-eared sliders that is 4 inches or above. Now, gently turn over the turtle and feel the bottom of the shell. 

If you find the plastron flat or slightly bowed out, you have a female slider in your hand. This shape helps the female sliders to store their eggs. 

On the other hand, if the plastron is concave (curved toward the spine), then you have a male slider. The concave shape allows the male slider to mount on the female slider during mating. 

4. The Size and Shape of the Tail 

Another obvious difference is the shape and size of the tails. Male red-eared sliders have longer and thicker tails. But the female red-eared sliders have shorter and thinner tails. 

You can also differentiate the male and female turtles based on the position of their cloaca. It is an opening in their tail that works as a urinal and sexual organ. The cloaca of a male turtle is near the end of its tails. In the case of the female, it is at the edge of their shells. 

As the cloaca of a male slider is towards the end of its tail, it can easily mate with female sliders.

5. Change of Color and Marking 

When red-eared sliders are born, they are identical. They have the same size and color. But as time goes by, male sliders change the color and marking on their body. Young sliders are green with bright yellow marks. 

See also  Can Red Eared Sliders Drown Underwater?

The yellow marks on a mature male slider become darker, and the body becomes close to black color. Then the yellow stripes look less prominent. But female red-eared sliders do not change colors too much when they mature. Therefore, the darker your red-eared turtle gets, the highest chance that it is a male slider.   

6. Shape of their Head

As the red-sliders get older, the differences get more prominent. Adult female sliders have larger and thicker heads than their male counterparts. This is natural, as the female sliders have larger bodies compared to the male sliders.

You will see the mature male red-eared sliders have long and thin snouts. The snout of a female slider is not so prominently shaped. 

7. Behavioral Differences 

There are also some behavioral differences in male vs. female red-eared sliders. A male red-eared slider can show aggressive behavior towards other males from an early age. They can get very possessive about their territory. But female turtles do not exhibit such behavior.  

The female red-eared sliders change their behavior when it is time to lay eggs. They spend less time in water and more time on the ground for a suitable spot for nesting. 

So, you may find female turtles smelling and scratching the ground. If they do not find a suitable nesting place, they might lay eggs in the water. They might eat less food than usual during this time. 

How To Identify Sex Of Baby Red-Eared Slider?

As you can see by now, identifying the gender of the red-eared sliders become possible when they grow up. It is not possible to know their sex when they are just hatchlings. These hatchlings have the size of a quarter. Therefore, it is difficult for general people to spot the differences.  

However, breeders of the turtles can tell the gender of a red-eared slider with a scientific method. They consider the temperature at which the slider eggs were incubated. The variation of incubation temperature creates different genders of red-eared sliders. 

The eggs incubated at 78.8 degrees F. will produce male red-eared sliders and the eggs incubated at 89.6 degrees F. produce female sliders. Hatchlings produced from eggs in between this temperature can be males or females. 


You must have learned all the differences between male and female red-eared sliders by now. There are some differences between the genders. However, you have to wait for the turtles to reach their mature age to spot all of them. Hopefully, you can now identify the gender of your little turtle friend. 

Sharing is caring!

About Author

Muntaseer Rahman started keeping pet turtles back in 2013. He also owns the largest Turtle & Tortoise Facebook community in Bangladesh. These days he is mostly active on Facebook.


This site is owned and operated by Muntaseer Rahman. is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to This site also participates in other affiliate programs and is compensated for referring traffic and business to these companies.