The penis of a turtle is nothing less than a purple giant in comparison to the organ of other animals.

It may sound weird to some, but today we are talking about the turtle’s penis because this marine animal achieves an astounding score showing blatant features in its reproductive organ.

Phallus or penis, the male sex organ, has rarely been talked about, but there are some unthinkable facts that may turn up your nerves shockingly.

The blue whale being the largest, has the longest penis in size, approx 8 feet, while a few barnacles have it eight times their own size, which is technically the highest body to penis ratio. The Yangtze turtle’s penis helps it in fighting, while the honey-bee system is a bit different as the organ gets ejected after the intercourse, letting the bee die off.

So here are some crucial realities about turtle genitalia you may be interested in, being an owner or breeder of this species.

Physiology of Turtle’s Penis

It shouldn’t be difficult to believe that the little turtle in your aquarium holds unique characteristics about its intromittent organ, which can mysteriously elongate to almost half of its own length.

The penis of a turtle looks horrifying with a hard-skinned barrel-shaped column and a tip of a mammoth monstrous head face.

The anatomy of the turtle penis is best reported by Diane Kelly in 2004 when she titled a paper “Turtle and mammal penis designs are anatomically convergent.”

Let’s find out more about the male turtle anatomy.

What Does a Turtle Penis Look Like?

Simply put, it is a fleshy hydraulic cylindrical structure that is flexible in a deflated state. The male turtle reproductive organ gets ready for copulation once this hydraulic skeleton gets gulped with fluid and forms an erection.

The turtle genitalia stays in the resting lay down position and looks more like a two fold state in everyday situations. Even if the turtle’s penis is uninflated, it looks enlarged and well settled in the cloaca.

With the increase in size, the penis initially bends towards the stomach and then gets the complete length anteriorly—the tip has glans, which are in stimulative motion when erect.

The seminal grooves are visibly long, and seminal ridges cover them all around, situated close to the glans.

Skin folds like fissures and sinuses surround it giving a grand monstrous look. Especially the pulsating movements of the ridges and the flower-like structure of the glans’s upper surface, which can open & close, isn’t an attractive sight.

Note: Unlike humans that have hanging sacs of testicles below the phallus, the testicles in turtles are stuck below the abdomen next to the kidney and stay hidden during intercourse.

How Big is a Turtle Penis?

The turtle’s penis size depends on the species variant and the size of the adult turtle. On average, the length of an uninflated organ can be as big as half the size of the turtle’s body, and it could be around 10 to 12 cm in length.

What is the Color of Turtle’s Penis?

It is in the dense shade in every turtle, with purple, dark grey, or black in color.

How Big is a Turtle Penis After Erection?

The phallus starts increasing as the blood flow streams faster to the organ. The erected penis can grow to almost 50% of its size and attain a length of approximately 15cm to 20cm, and it can thicken to more than 75% after a complete erection.

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Reproduction: How Do Turtles Mate

Turtles have a proven development stage of millions of years, and thus, like other animals, they follow a typical breeding pattern. With multiple species, types, and categories, both the sea and land turtle habitats have similar reproductive mechanisms.

Most of the species meet their potential partners only during the mating season, while others like green sea turtles stay together with their mates for almost a year.

Mating Season

Turtle’s mating season begins after the winter season is over, usually when the temperatures are warmer and the days are longer than nights.

Mating in too warm conditions will result in female turtles while pairing in too cold temperatures will produce male hatchlings. However, the turtles do not care about producing specific males or females but are naturally aware of the best mating time.

Note: The optimum temperature when the turtles mate is around 28 to 30 degrees Celsius. Eggs lay in this time will have hatchlings in balanced gender.

Ideal Conditions

When the adult turtles feel the warmth, they start moving towards the sea beaches, where males usually reach earlier than females to claim their chance.

The male turtles reach their maturity age earlier than the females. The average age of maturity of turtles varies as per the species. It is between 10 to 12 years for some, while for a few others could be as late as 34 to 40 years.

Both males and females seem to mate several partners, while males seek a partner as long as they can while females only copulate until they have enough sperm to fertilize all the clutches. The males copulate every season while females after 2 to 3 years.

How do Turtles Reproduce

As they find a suitable partner, the males start chasing the females and bite them on the body parts. If the response is positive, the male will hold the female from the back of the shell as they both have the reproductive organs neighboring the tails.

The males attach themselves to the females using their sharp claws, tightly sticking or inserting them into the shell, which might create a wound.

The intercourse may take an hour or more until the male detaches itself and moves to find another partner. If they have enough sperm for all the eggs, the females will not mate anymore. And starts finding a nesting area; usually digs deep into the mud.

The female turtle can lay up to 8 clutches, each having 70 to 100 eggs. After every clutch, the female goes back to the ocean and returns after two weeks for the next batch of clutches.

The incubation of eggs lasts between 7 to 11 weeks. After that, the juveniles come out of the eggs to feed themselves and move slowly towards the ocean.

Sea Turtle’s Penis and Sexual Reproduction

Around 7 kinds of sea turtles are found predominantly on the planet today, according to biologists, which are:

  • Kemp’s Ridley
  • Flatback
  • Loggerhead
  • Olive Ridley
  • Hawksbill
  • Green Sea Turtle
  • Leatherback
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They show up in variant shades and sizes.

These species prefer to stay singularly throughout their life and only meet their partners to fulfill sexual urges. However, green sea turtles are seen to live with their partner for a longer session, from mating to nesting.

Anatomy of Sea Turtle Penis

It is a single vascular erectile body, subdivided into corpus fibrosum and corpus spongiosum. The fibrosum is dense, while the spongiosum is stretchable.

The collagen fibers that are present in the walls of the sea turtle penis enhance flexural stiffness. These fibers are exceptionally impervious to twisting or shape change because they are organized in linear orthogonal arrays rather than crossing helices.

What Does a Sea Turtle Genelia Look Like?

Two retractor muscles running in the lower surface connect the organ to the lumbar vertebrae. As the retractor muscles contract, the penis straightens to enlarge and form an erection from the backside of the body.

The horrible structures of glans differ as per the species, where sea turtles display spike pointing heads with single fold grooves, while few other species have huge thick wide glans.

Sea Turtle Penis Size

Sea turtles have long-sized reproductive organs as the other species, which are usually half the length of the body and darkened a shade in color.

When the tension increases, the phallus straightens and enlarges to approx—20 cm in length with high stiffness.

How Does the Sea Turtle’s Mate?

When the environment is warm and temperate, the mature sea turtles start moving towards the beach. These turtles behave weirdly on a first-come, first-serve basis, where males have to indulge in small fights with the co-males to get a partner first.

For mating, the males come over the female’s s body while they are swimming horizontally and hook themselves at the back of the females with the help of sharp claws.

The reproductive organs of both genders are situated together below the tail. For coupling, the males move with the erected organs to a female.

If the female accepts the male, it instantly tries to mount over the female’s shell and force the penis into the female cloaca.

These copulating couples can stay together for around 24 hours, not letting other males to mate with their partner.

There are few risky situations for both adults while mating. If unable to handle the fat on their backside, the females may die out if they cannot flip themselves back on foot.

Fun Fact: During intercourse, turtles create a strange mating sound that sounds quite similar to velociraptors. As a result, Jurassic Park’s sound designer recorded the mating turtles’ sound to be utilized in the movie for the smart raptors.

How is a Red Ear Slider’s Penis Different Than Others?

Red ear sliders are a popular turtle species on the international market, with distinctive red bands on their ears that set them apart from other turtles.

The males of this species get sexually mature at two years of age while the females at 3 to 4 years of age.

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Like other turtles, the reproductive organ of the red ear is quite long in size. But the red ear slider’s penis is slightly different than other males of the species.

Here the penis is formed out of the cloaca through hydrostatic pressure that reverses the cloaca to get an elongated groove channel-like structure filled with sperm. This is actually stored on the ventral floor of the cloaca, usually in purple or black shade.

Comparison with Other Species

The sexual organs found in turtles are quite similar to mammals but have biological differences. Here we will find out the specific features of the penis in humans (mammals), hemipenes (reptiles), and tortoises.


Mammals represent a medium-sized penis, while some reptiles, such as birds, have an utterly absent state. Tortoise, on the other hand, has long-sized structures.

Urethral Tube Type

Mammals have a closed urethral tube within the phallus, while the reptiles have an open groove system. Whereas in turtles, the closed urethral tube requires lineage-specific specialization.

Penis in Number

Mammals have a single long penis, while some reptiles like lizards possess two penis size structures of considerable long length. Turtles have single massive structures.

Inflation and Erection

The penis in mammals is inflated with blood vessels that need to form an erection before intercourse. It is inflated with lymphatic fluid in reptiles and everts with pressure inside the female. The turtles have a hard shaft head leading with a stream of blood-inflated glans.

Exciting Facts About Turtle Penis

Some of us may give a damn about the reproductive organs of animals, but the world is full of astonishing creatures with surprising natural gifts on their body.

Here are some of the striking factual truths about the turtle penis.

Color of Snapping Turtle Organ

The color of an adult snapping turtle penis is usually bright pink.


If they find themselves at potential risk, the turtles force out their penis in fear and tension to put away the handler. Although the heavier turtles either do not easily get nervous or are unable to extend their organ in sensing danger.


It is hard to determine the gender of a turtle until the cloaca is investigated, locating the penis if it is there or not. The young turtles are held in a manner so that the penis, if exists, extrudes out by the turtle itself.

Demonstrate Aggression

Penis display is a displacement behavior by the turtle.


Species like Yangtze giant softshell turtle use their penis to hit the competitor.


The sea turtles have the ability to detect peculiar smells on land as well as inside the water.


The turtles have been a point of research for years, and scientists have shown deep interest in finding biological facts about this animal.

This aquatic or semi-aquatic animal shows multiple similarities to humans in terms of organ structures and functions, and likewise, the turtle penis poses deep reckoning functionalities.

The experts have yet to decode the strange looks and behavior of the turtle’s penis, and the topic is so vast that we hardly know much about its patterns.

Related Resources:

African Sideneck Turtle: Species Analysis

About the Author

Victoria Lamb

Victoria is a freshwater aquatics specialist, fish keeper, and amphibian enthusiast. She has had more than 6 years of experience caring for aquariums and keeping several fish species, and her home boasts of 3 aquariums and a garden pond. Her goal is to educate fish owners on raising healthy and happy aquatic pets.

Career Highlights:

  • Has worked with several aquarium manufacturers as a consultant
  • Organized and hosted workshops on freshwater fish keeping at retail stores, educational facilities, and libraries
  • Released content for the amphibian community through her writings

Educational Highlights:

Bachelor of Science in Animal Behavior and Welfare

  • University of Lincoln, Lincoln, UK (2014-2018)

Writing Experience

Victoria has done ghostwriting for many aquarium and pet websites in the past. She has also worked for Canada's largest natural health magazine- ALIVE, with 300,000 monthly circulations as a freelancer. She had six published articles on animal behavior and welfare during her graduation for her thesis.

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