Category: Turtles

There are about 356 species of turtles, including tortoises and sea turtles. As different as they are from each other in terms of size or color, they all have one thing in common: a shell.

If you’re wondering how the turtle’s shell grows, you should know that like regular bones, it actually grows with the turtle as they age.

In this article, we take a deeper look at how the turtle shell works, what it’s comprised of, and what happens if it’s damaged. So, read on!

What Exactly Are Turtle Shells Made Of?

The main mineral found in a turtle’s shell is calcium phosphate, which is the same mineral that is a substantial part of our own bones and teeth. There are many misconceptions about a turtle’s shell, including that they can wriggle out of it and trade it in for a newer and larger model, kind of like the hermit crab (which does change “homes”).

But nothing could be further from the truth! A turtle’s shell is literally a part of the turtle. It can’t fall off or change just because the turtle has grown bigger. The shell grows with them. It’s made from the turtle’s spine, pelvis, and rib cage. They are the only land animal in which the hip and shoulder bones are found in the ribcage, which is in the shell.

So, since the shell and many of the turtle’s bones are bound together, the turtle’s shell literally grows with them.

The Ribcage

The ribcage is a part of the shell, so turtles need specialized muscles found inside the shell to help them breathe. The shell itself can’t expand and contract to accommodate breathing, so these muscles help turtles get the oxygen that they need.

Does the Turtle’s Shell Shed?

The shell is at one with the turtle, but it does shed something called scutes, which are the different plates that make up the shell.

Scutes are comparable to scales and function as protection in a similar way. These bony external plates can be found on a turtle’s shell, but they are also on the feet of certain birds and the skin of crocodiles. Almost all turtles have scutes, with the exception of soft-shelled and leatherback turtles.

To a certain degree, they can be compared to fingernails, as they are essentially epidermal structures made up of the protein keratin (which also forms our hair and makes up the outer layer of our skin, the epidermis).

As turtles grow, they go through molting, also called ecdysis, which is the shedding of their scutes. This process is an important one because the shell itself can’t expand, and the process of shedding the outer layer of scutes enables the turtle to grow newer and larger scutes. Molting also helps remove fungi or parasites and dirt or debris found on the old scutes.

What Happens If the Shell Is Damaged?

Since the shell grows with the turtle, they can’t just switch to a new one when it’s damaged. A damaged shell can prove fatal if the damage is severe. If it’s relatively minor, the shell can heal on its own after a while, but serious damage will require veterinary care.

Severe damage can expose the turtle to infections or other complications and affect the turtle’s ability to swim, move, or eat, which will also impact their health. Some turtles will need rehabilitation until their shell has healed.

The shell’s outer layer is made up of keratin. The second layer is primarily composed of the bones, and directly under the bones are the turtle’s internal organs. A serious crack that exposes the organs increases the likelihood of infection.

A cracked shell is usually treated with painkillers and antibiotics if needed, and the bridge technique is used. This entails fastening metal or plastic brackets or zip ties to either side of the crack to form a “bridge” to encourage healing.

Unfortunately, if the damage is extensive, including a shattered shell, euthanasia may be the best solution.

Are There Diseases That Affect the Shell?

There are a few diseases that can impact the shell and consequently, the turtle’s health.

Dysecdysis

Dysecdysis is the abnormal shedding of scutes; this is when the scutes are shed too often or don’t shed properly, which can cause infection.

If shedding occurs too frequently, it can leave the turtle’s bones and shell soft and unprotected. This is also a potential sign of a more serious medical condition like kidney failure.

Metabolic Bone Disease

Bone health is essential for turtles because it directly impacts shell health. Metabolic bone disease can occur if the turtle has inadequate calcium intake or not enough sunlight exposure. It can also result from diseases of the thyroid, kidneys, and liver and causes misshapen or soft shell bones.

Shell Rot

Shell rot is ulcers or abscesses that affect the scutes, with defects or pale or dark pink discolorations. This can result from an inadequate filtration system or one that isn’t cleaned enough, as well as infrequent water changes or too low of a temperature.

What Are Turtle Shells For?

Turtle shells are certainly all-purpose! They are homes, shields, shovels, camouflage, and insulation.

Conclusion

Turtle shells are made primarily of calcium phosphate and are essentially bones, which is why they grow along with the turtle.

Molting scutes enable turtles to grow along with their shells. A damaged shell is potentially a big problem, though it depends on how bad the damage is. Fortunately, a vet can often bridge the shell to allow for healing.

Turtle shells are just as unique as the turtles themselves. Be sure to keep an eye on your turtle’s shell. If you see anything worrying, don’t hesitate to bring your pet to your veterinarian.

Featured Image Credit: Four Oaks, Shutterstock

The post How Do Turtle Shells Grow? Science-Based Facts & FAQ appeared first on Pet Keen.

When you think about turtles, you likely think about their shells and the adage, “slow and steady wins the race.” What you probably don’t think about is how they hear. But now you might wonder: Do turtles have ears?

The short answer is yes, but they aren’t the traditional ears that you’re familiar with, like a dog’s ears or your own. Turtles have internal ears that are extremely difficult to see.

Read on to learn more about how a turtle’s ears work!

A Turtle’s Ears

Turtles have internal ears rather than the external ears found on most mammals. They have inner and middle ears, but we can’t see these because they are covered with a thin flap of skin. This flap is called the cutaneous plate and is similar to the skin on the turtle’s head.

Turtles also don’t have eardrums like us; small bones in their inner ears help interpret sounds.

How Do a Turtle’s Ears Work?

The shape of a human’s external ear is designed to capture sound waves and funnel them into the inner ear, where the sound is processed and reaches the brain. Since hearing isn’t a crucial sense for turtles, the hearing portion of the brain is small.

Also, since turtles don’t have external ears, the sounds that they can hear are limited, particularly in comparison to mammals with external ears.

Sound waves hit the turtle’s cutaneous plate, which vibrates and sends low-frequency sound waves into the ear canal. The inner ear then processes the sound waves, which are transmitted to the turtle’s brain for analysis.

These sound waves and vibrations help turtles navigate, alert them to any potential predators, and help them find prey.

How Well Do Turtles Hear Underwater?

Turtles hear better underwater than when on land. They can hear frequencies around 500 Hz (rolling thunder can be around this range), which is higher than most other reptiles.

The subcutaneous plate and layer of fat inside their ears become conductors of sound while they’re in the water. The sound travels to the middle and inner ears. Turtles are also sensitive to air and water pressure and can detect changes in water pressure caused by swimming fish or an approaching predator.

Sea turtles hear best at around 200 to 750 Hz and don’t respond to sounds above 1,000 Hz. High frequencies include sounds like birdsong, which can range from 1,000 to 8,000 Hz. The subcutaneous plates allow vibrations in and keep water out.

How Well Do Turtles Hear on Land?

Turtles hear better in the water than on land, but they can respond to changes in air pressure in addition to vibrations. So, they might not hear a bird chirping, but they’ll sense the vibrations of the bird flying nearby.

What Are a Turtle’s Best Senses?

Turtles have all the same senses as other animals, but most of them are sharper than their hearing.

Smell

The turtle’s sense of smell is thought to be their strongest sense. Sea turtles can smell prey, such as fish and shrimp, even in murky waters.

They also use their sense of smell on land to select a mate; males and females find each other by smelling their respective pheromones. Their sense of smell additionally helps them to avoid predators.

Sight

Turtles have excellent sight and can easily locate food and avoid predators. They can also detect and tell the difference in shapes, patterns, sizes, and colors.

They can see near-ultraviolet, violet, yellow, and blue-green light. Unsurprisingly, they also see better underwater than on land, and it’s believed that they don’t have any peripheral vision.

Touch

You might think that turtles wouldn’t be sensitive to touch because of their thick skin and shells, but they are surprisingly touch sensitive. Various nerves run along their skin and shell, enabling them to feel when it is touched. It’s believed that sea turtles do not have pain receptors in their shells, though, so they likely won’t feel pain when their shell is mildly damaged.

Compass (Sort of)

Sea turtles have a kind of internal compass, and sea turtle hatchlings use it to orient themselves after getting through the surf from their sandy nests. They do this by orienting themselves to Earth’s magnetic field. It also enables adults to stay on course while migrating, so sea turtles can navigate wherever they want to go.

How Do Turtles Communicate?

It was long believed that turtles didn’t hear or have vocal cords, so they were thought to be non-vocal, which is not surprising because most people have probably never heard a turtle make any sound.

But a 2022 study found that turtles communicate with quite a diverse range of vocalizations. The most common sound that they make is hissing, which is thought to express fear.

Turtles expressing hostility or a warning tend to hiss and pant heavily, and mating turtles make high-pitched sounds. It’s also thought female turtles emit sounds as a way to communicate with their unhatched young. Sea turtles likely make these sounds to encourage their young to hatch around the same time. Baby sea turtles are picked off quite substantially by predators after hatching, so hatching en-masse helps increase the chances of more hatchlings surviving.

Conclusion

Turtles likely hear more than most people might expect, but their hearing isn’t their strongest sense. They can hear low-frequency sounds and will stop hearing sounds altogether once they hit 1,000 Hz.

A turtle’s ears are internal, with a skin covering them, so it’s difficult to see them, but this enables turtles to keep out water while swimming.

Featured Image Credit: DiPres, Shutterstock

The post Do Turtles Have Ears? Hearing & Other Senses Explained appeared first on Pet Keen.