The turtle’s shell, or the outer shell of a turtle, is part of its body also known as its exoskeleton and is not just a hard protective housing. Rather, its shell is made of bones, skin, and keratin, laced with nerves and blood vessels. So, can turtles feel their shell?
They sure can. Whether it’s a gentle touch or a sharp impact, turtles can sense it on the surface of their shell, feeling discomfort when their shell is injured. (See our first aid section if your pet turtle has an injury)
When you break down its composition, the outer layer of a turtle’s shell is made of scutes, which are the plates that make up the shell. Generally, these scutes are made of keratin and underneath them is skin above a layer of hard dermal bone.
There’s a little more to it, of course, so today we’ll discuss the makeup of a turtle’s shell, as well as health conditions that can compromise this robust protection that Nature has afforded them.
Let’s talk about turtles, their shells, and the fascinating facts behind them!
Table of Contents
The Turtle Shell Feels Touch
Just like the rest of the turtle’s body, the shell, enveloped in a thin layer of skin, has nerves and blood vessels, making it sensitive to touch and pain. These nerves mean that the turtle’s shell can feel touch, pain, and even temperature.The shell is essentially an important living organ, which bleeds if injured.
Interestingly, the bones found within the shell include ribs, the pelvis, the backbone, and other bones (such as dermal bone plates). It is believed that the shell evolved from the turtle’s rib cage!
For turtle owners, it’s crucial to protect the shell of your pet turtle, ensuring their habitat is free from hard surfaces and potential threats. Make sure there aren’t sharp edges and points in its enclosure that could scrape or otherwise injure the shell. Also, keep animals such as cats and dogs away – they can hurt or even kill your turtle!
Since turtles can feel when you touch their shell, you’ve got to be careful handling more dangerous species like snapping turtles – Find out the RIGHT way to pick them up when you’re done here. The link will open in a new window so it’s ready when you are!
Anatomy Of The Shell
A fun fact about turtles is that their shells, much like human fingernails, are made of keratin. This outer layer, or the hard keratin plates on the outside of their shell, adds an extra layer of defense against external threats.
The turtle’s shell consists of the ‘carapace’ and the ‘plastron’, fused by the ‘bridge’. The plastron is the lower part of the shell –the bottom part of the turtle — while the carapace is the upper part of the shell on the turtle’s back.
Scutes
The scutes are the plates on the shell and usually make up the outermost part of this structure. Aquatic turtles shed old scutes, which are replaced by new ones as they grow, although terrestrial turtles such as tortoises do not.
With aquatic turtles that shed scutes, new ones grow in as keratin layers are added to the underside of the old scutes.
Typically, the scutes of the carapace are more pigmented than the scutes of the plastron, which why the bellies of turtles tend to be lighter are lighter in color while the upper shells are usually darker.
With some chelonians such as tortoises, scutes are ringed with new rings forming as the turtle grows. As such, experts can estimate the age of an adult turtle by simply counting the rings of the scutes!
Carapace
The carapace or ‘upper shell’ is the dorsal part of the shell and is convex in shape, and this is more pronounced in some species than others. For instance, some turtles such as the spiny softshell turtle (Apalone spinifera) and the African pancake tortoise (Malacochersus tornieri), have an almost flat carapace.
The carapace consists of the backbone (spine), as well as ribs fused to dermal plates beneath the skin to create that hard shell. Atop the skin are scutes, which are plates made of keratin, and these scutes protect the shell from bruises and scrapes.
There is also a keel(ridge) that runs down the middle of the shell. This keel is highly visible in some species such as keeled box turtles (Cuora mouhotii) and map turtles (Graptemys).
The shell is generally uniform unless it’s been damaged over time by predators or disease and healed poorly.
Interestingly, not all species of turtle have hard shells; leatherback sea turtles, for instance, have flexible shells covered by a thick layer of skin. Softshell turtles, such as the leatherback sea turtle (Dermochelys coriacea) and Florida softshell turtle (Apalone ferox), lack a hard shell. These turtles do not have scutes and there is limited ossification to their shells. Instead, their shells are covered by skin!
While they don’t have an ultra-hard shell, don’t think softshell turtles can’t be aggressive. Find out more in ‘Are softshell turtles dangerous?‘ – the answer might surprise you!
Softshell turtles are aquatic so the lack of a hard shell is to their benefit. It helps to make them nimble and quick, especially in the water.
On land, freshwater softshells are still very fast, and you can see it in the video below which shows a softshell turtle making a lightning-fast escape into the water.
Plastron
The plastron is the underside of the shell and is commonly referred to as the ‘belly’ of the turtle, and it is connected to the carapace by the ‘bridge’ – although the bridge is considered to be part of the plastron.
Many have described the plastron as an exoskeleton and it has even been compared to osteoderms, which are bony plates embedded in the skin of some reptiles.
A good example would be the hard plates on an armadillo – those plates are osteoderms. While the plastron is similar to these, there are certainly some differences but it gets a bit technical.
The quick explanation would be to say that plastrons possess certain cells (periosteum, osteoid, and osteoblasts) that are missing in osteoderms, but beyond this, they are very similar in function.
Some turtles, such as box turtles, have hinged plastons. This hinged plastron allows them to completely close their shells!
Box turtles can place their entire bodies (head, neck, and limbs) inside these hinged shells when they feel threatened, allowing them to remain relatively safe from predators or other external factors that the turtle is worried about.
This hinge is located between the abdominal and pectoral scutes and it’s easy to tell if a turtle has this handy evolutionary defense – you’ll see them use it when you get close if they don’t know you!
The shape of the plastron can be used to determine the sex of some turtle species. With some species, females will have more convex plastrons, while males’ plastrons will be more concave.
This is by Nature’s design – the concave shape of the male’s plastron makes it easier for them to mount the females during mating.
Ultimately, the plastron serves to protect the underside of the turtle, the same way that the carapace protects the upper side – but as you can see, there’s a whole lot more to this amazing evolutionary armor!
For more, see our full guide about turtles anatomy which is full of images for clear explanations.
Diseases that can affect a turtle’s shell
While a turtle’s shell provides robust protection against many injuries, it’s important to remember that turtles, from baby turtles to adult land turtles, are not invulnerable. Predators can occasionally bite into or through the shell, but there are also diseases that can compromise the integrity of the mighty shell.
The most common ones are ‘shell rot’ and ‘shell pyramiding'(a form of metabolic bone disease). Let’s take a look at these so that you’ll know exactly what they do and how this affects the turtle’s natural armor.
Shell Rot
Shell rot is clinically known as Septicemic cutaneous ulcerative disease (SCUD) and is generally caused by poor husbandry, such as keeping the turtle in a dirty enclosure or abrasions that become infected by fungi and/or bacteria.
Usually, an abrasion of the shell comes first. This might be from bites, burns, or other physical traumas to the shell.
If these are not disinfected or if the enclosure is simply unclean, then the abrasion will go on to become infected and these infections can sometimes go deep into the shell.
As a result, the turtle may develop deep ulcers and pitting which often extends into the bone below the shell as the scutes become compromised and unable to protect the turtle.
Symptoms Of Shell Rot
Shell rot is quite easy to identify because the shell simply won’t look right. If you notice abnormal pitting or other damage to the shell, it’s best to get them to the vet right away.
Shell rot can occur on the plastron or the carapace and like most diseases, your turtle will have the best chance of recovery if it is treated early. Early treatment also helps to minimize the damage and the healing time involved, so this is vital.
Symptoms of shell rot include one or more of the following:
- Dimpling or pitting of the shell.
- Discoloration of the scutes.
- Loose scutes that seem to be lifting away from the others.
- Soft areas on the shell.
- Cracks in the shell.
- Fluid underneath the scutes.
- Discharge or unpleasant smell from the shell.
- Scutes coming loose or completely off and revealing bony tissue beneath them.
Prevention
Having a clean enclosure is the best defense for preventing shell rot, and you should also ensure that there are no sharp or pointy objects inside of the enclosure that might damage your turtle’s shell.
Here are some things that you can do to prevent shell rot if you have a terrestrial turtle:
- Change the water in the water dish daily. Provide fresh water and clean the water dish thoroughly every day.
- Spot clean daily to remove fecal matter and urates (salt build-up leftover from your turtle’s urine).
- Clean the entire enclosure once a month, disinfecting it with diluted bleach and replacing the substrate within the enclosure.
- Inspect the turtle regularly to look for any abrasions, cuts, pitting, or other anomalies on their shell. Look for discoloration and soft spots, as well.
- Provide the turtle with a balanced diet, so that if damage DOES occur your turtle will have a strong immune system to help protect and heal them.
Treatment
It is important to get the vet involved if you suspect the onset of shell rot. They can provide you with medicines, as well as detailed instructions on what you’ll need to do to help your turtle heal.
Caught early, treatment usually involves treating the affected area with chlorhexidine solution and a soft bristle brush. If the turtle is terrestrial, you will also need to ensure that the shell stays dry.
The vet may also prescribe systematic antibiotics such as enrofloxacin if the infection is severe. Usually, these will be applied to the shell once a day, but the vet will tell you if this is the case and you should follow their instructions.
If the shell rot is severe, the vet may need to keep the turtle/tortoise at the veterinary clinic to observe them until the turtle is better.
It is also important to note that you should keep any affected turtles away from healthy individuals, as Shell rot is contagious and may spread from one turtle to another if quarantine is not observed at its onset.
Pyramiding
Pyramiding is a form of metabolic bone disease, which is a disease that causes abnormal bone and shell growth. The limbs of the turtle may become uneven and the shell exhibits an abnormal upward growth of the scutes.
This creates a pyramidal shape, which is where this affliction derives its name.
Terrestrial turtles, especially tortoises, are more likely to suffer from pyramiding and Sulcata tortoises are very susceptible to this disease.
Causes
There are different causes of pyramiding, although the most common ones are improper diet, lack of exercise, genetic predisposition, and poor husbandry. Here are some other factors known to contribute:
- Terrestrial turtles are generally more herbivorous than carnivorous and because of this, feeding them foods high in fat or protein can lead to pyramiding.
- Lack of exercise
- Overfeeding
- An imbalance of phosphorus and calcium in the turtle’s diet
- Underexposure to UVA and UVB light which affects their ability to absorb calcium
Prevention
Preventing pyramiding requires attention to the turtle’s diet and lifestyle. Here are some things that you can do:
- Ensure that your turtle is active and receives a lot of exercise.
- Research your turtle’s diet. If the turtle is more of a plant eater then provide more plants, but if the turtle species is more carnivorous then you should offer more animal matter. Consider their age, as well, as this often determines their optimal diet.
- Regardless of the species, ensure that you feed the turtle foods with a limited fat content.
- Supplement the turtle’s diet with calcium.
- Ensure that the turtle receives adequate exposure to UVB and UVA light.
- For terrestrial turtles, ensure that the environment in which they live isn’t too dry. Low humidity has been known to cause pyramiding.
Treatment
Treatment can be tricky, as the physical effects of pyramiding cannot be reversed, although it may be minimized with younger turtles. The causes of pyramiding, however, are known and can be prevented with a little care and foresight.
If the turtle is still a juvenile, once you correct the conditions that are causing the pyramiding, the turtle’s growth should return to normal as the animal still has a lot of growing to do.
This significant growth can result in the shell returning to normal or at least greatly minimize the damage.
As the turtle grows, the effects of pyramiding should become less noticeable, but if the turtle is an adult, then there is little that can be done beyond correcting the factors contributing to pyramiding.
You can read a little more about pyramiding at the Arizona Tortoise Compound – They have an excellent article on the subject here.
Another consideration for turtle owners is the potential for shell fractures. These injuries can occur from a significant amount of pressure or a sharp impact and require immediate medical attention to prevent further harm to the turtle’s internal organs.
Frequently Asked Questions
Understanding the different ways turtles interact with their environment can also shed light on their behaviors and needs. For instance, red-eared sliders, a popular pet turtle species, show a variety of responses to different kinds of touch, from seeking light touches to retreating from painful bites. Their long necks and the ability to retract into their shells offer fascinating insights into how turtles shell help them navigate their habitat, from land to shallow water.
Do turtles feel pain through their shell?
Yes, turtles can feel pain through their shell due to the nerve endings that run throughout the structure. Thus, if a turtle is attacked by a predator, it can still feel every scratch or bite through its shell.
There are instances where people have assumed that the turtle couldn’t feel it and so they’ve drilled holes into the turtles’ shells. This is something you should NEVER do as it definitely hurts the turtle.
Similarly, ensure that pets such as dogs and cats don’t scratch or bite the shell. It might look like your turtle is protected, but it is still a painful ordeal for them.
Do turtles like their shells rubbed?
Turtles don’t usually enjoy having their shell rubbed and while dogs and cats like rubbing, there is no indication that turtles feel the same way about it – although some may stretch out their necks for a nice chin scratch.
If you must handle them, keep the interaction limited, and you only want to rub or apply pressure to the shell when you are inspecting it for health reasons.
This will help to keep your turtle’s stress to a minimum and those regular inspections can help you to catch any health issues early.
Does it hurt a turtle to pick it up by its shell?
This depends on how you pick up the turtle, as well as if the place you are holding it is injured. If the shell is injured or diseased, avoid touching it, as it can cause the turtle excruciating pain.
Overall, picking a turtle by its shell is okay and won’t hurt the animal, but you should research the proper way to hold them, as the turtle’s attempts to escape might result in dropping them and your turtle could be injured!
Can a turtle live without its shell?
A common misconception is that the shell is a housing that the turtle lives in and cartoons commonly depict a naked turtle hiding inside. This is definitely fiction – the shell is a part of the turtle’s body!
It is composed of keratin and skin, as well as the ribs, pelvis, backbone, and many other important bones along with veins and nerve endings interlaced throughout.
As such, removing the shell would be excruciatingly painful and fatal for the turtle.
Can Turtles Feel Their Shell? — The Conclusion
The shell is one of the most identifying features of the turtle and these shells can be hard or soft. They help to protect the turtle from attacks and harsh environments, and they are composed of living tissue.
This tissue has blood vessels and nerve endings, along with important bones such as the rib and backbone, and if you touch the shell or if the turtle is attacked by a predator, the turtle can feel every bit of it!
This makes it extra important to always handle your turtle with care and keep any other pets away from them – what looks like a harmless do or cat scratch on a hard shell is actually very painful and these animals can even kill your turtle!
As the shell is composed of living tissues, it can also be affected by disease and injury, so if you own a turtle then proper care includes regularly inspecting that shell to ensure that it is firm to the touch and healthy.
It’s an important part of your turtle’s body, after all, and now that you know you can use this information to stress your turtle a lot less. Handle their shells carefully – they can FEEL it!