Are turtles able to leave their shells?
Will a turtle outgrow its shell?
Turtles have very complex anatomical structures, and their shells are no exception.
People often wonder if a turtle can survive without its shell.
After all, hermit crabs leave their shell searching for new ones, so why would a turtle be different?
To answer these questions about these beautiful reptiles, it is vital to understand a turtle’s anatomy and the vital role its shell plays.
This article will take an in-depth look at a turtle’s anatomy and how its shell functions.
Table of Contents
Are Turtles Attached To Their Shells?
A turtle’s shell functions as part of its skeleton, a fundamental structure, and the ribcage and spine are fused with the carapace (top half and outer layer of the shell). The plastron (bottom half of the shell) is made of bones, which function much like the sternum and clavicle of other four-legged animals.
The shoulder blades are found inside a turtle’s ribcage, which is very different and a more complicated structure compared to other vertebrates.
Unlike a hermit crab, which can leave its shell freely, a turtle’s shell is not something it simply carries around to protect itself.
A cracked or broken shell is the same as a human having broken ribs or a gash in their skin.
The turtle shell also protects vital organs and internal structures from the air, dangerous bacteria, and predators, and it keeps these organs from falling out if a turtle should be turned upside down.
What is the Structure of a Turtle’s Shell?
A turtle’s shell is made of bones, leathery skin, and cartilage.
The bones of a turtle are fused to dermal plates, which are hardened skin similar to bone.
Covering the dermal plates is a layer of vascular skin, which means this skin surface contains blood vessels.
Like our fingernails and hair, scutes, which are made of keratin, cover this vascular skin.
These scutes protect the traditional skin and dermal plates underneath from becoming bruised or injured.
If anything punctures the scutes, the turtle will bleed, and while the dermal plates do a great job of protecting a turtle from predators, any puncture through them will require a lot of healing.
For stability, scutes are arranged to overlap the areas between the dermal plates and other bones instead of aligning with them.
Some species, such as softshell pig-nosed turtles and leatherback sea turtles, do not have scutes.
Instead, their bones are covered with a lighter skin-like membrane and allow sea turtles to be more efficient swimmers.
As previously stated, turtles are pretty different from other vertebrate animals because their scapula, or shoulder bones, are located inside the turtle’s rib cage.
Since a turtle shell is connected to nerve endings, a turtle will feel pain if its shell is damaged.
Some turtles even enjoy being petted by their owner once they have bonded with them, but be aware this will take a lot of patience.
What is the Purpose of a Turtle’s Shell?
The main purpose of a turtle’s shell is to protect it from potential predators.
Some turtle species, such as the Eastern box turtle, can bring their carapace (outer layer) and plastron together to completely enclose their head, legs, and tail.
Other species cannot wholly retract their vulnerable extremities into their shell, but their bony shell still offers them protection.
While some animals have learned to break this defense, such as large birds who will drop a turtle onto a rock to crack its shell, it is often more trouble than it is worth as modern turtles do not offer much in the way of food.
Most turtle shells are dark colors, and this allows them to absorb heat.
A turtle’s shell also protects its insides from becoming overheated and dehydrated when the turtle is in direct sunlight.
Without a shell, a turtle’s internal organs would dehydrate in the sun before the animal would be able to absorb enough heat for proper bodily function.
In addition to absorbing heat, a turtle’s shell also helps them absorb UV light, which is essential for the turtle to synthesize vitamin D.
If you were to paint a turtle’s shell, it would become very sick from not being able to absorb UV light rays.
This is because a vitamin D deficiency keeps a turtle’s body from adequately metabolizing calcium.
This, in turn, will lead to a turtle’s body leaching calcium from its bones.
Without enough calcium, a turtle will develop metabolic bone disease, known as MBD.
MBD is an incurable disease which leads to bone deformities, and it is excruciating for the turtle before ultimately leading to death.
Signs of MBD include lethargy, inability for the turtle to walk or stand, bumps along the legs and tail, and a softening of the carapace and plastron.
As the shell softens, it increases the chance of causing damage to the attached spine.
Metabolic bone disease is easily preventable by providing a calcium supplement powder with vitamin D3 when feeding your turtle.
Will A Turtle Grow Out Of Its Shell?
A turtle is not able to outgrow its shell.
Since a turtle’s shell is a part of its body structure, a turtle cannot survive without the protection of its shell.
As a turtle’s body grows larger, the shell expands to accommodate the larger body.
In addition to a balanced diet, proper calcium and multivitamin supplements will help maintain proper healthy shell growth.
Providing a dry, warm basking spot for aquatic and semi-aquatic turtles aids in the shedding process, promoting shell growth.
Terrestrial turtles will also do well with a soak in water at least twice a week to encourage shell health.
This shell hydration will also prevent issues with dry shells, such as cracking or chipping.
While turtle shell growth slows as the animal gets older, the shell will continue to grow for the rest of the turtle’s life.
Will A Turtle Be Able To Survive A Broken Shell?
Luckily, a broken shell isn’t an immediate cause for panic, but it is a severe medical condition.
A crack or break in a turtle’s shell is very similar to having a crack in your fingernail or a cut on your skin.
If left untreated, these types of injuries will lead to significant infections.
A physical injury doesn’t always cause a broken or cracked shell.
Improper diet and poor enclosure conditions such as improper temperature or humidity will cause cracks in the shell.
If these cracks become infected, it will lead to shell rot, which is a severe condition for your turtle.
A calcium deficiency, a lack of sunlight, and many different diseases will cause shell deformities.
If your turtle is suffering from shell rot, be sure to investigate underlying conditions such as kidney damage, liver disease, or thyroid issues.
With a proper treatment regimen prescribed by a veterinarian who specializes in reptiles, your turtle will be able to make a full recovery from shell rot.
Once the infection causing the shell rot is eliminated, the shell will resume its average smooth growth.
There are turtle shell conditioners on the market which aid in moisturizing the shell and keeping cracks and chips from forming.
This type of shell conditioner is massaged into the turtle’s shell once or twice a week, and it gives the shell a healthy shine.
The turtle shell conditioner also helps maintain a cleaner shell by allowing any dirt to rub right off with a clean cloth.
There are also antibacterial ointments and sprays to keep infections from getting into any cracks or chips in your turtle’s shell.
These conditioners and antibacterial treatments help your turtle recover from any shell issues very quickly and are safe to use at home.
Turtles are hardy animals, and they are very capable of recovering from a broken shell quite easily.
A turtle’s shell is equally resilient, and with proper care, it will grow to fill in any cracks.
However, once shell trauma has occurred, you will likely be able to see some evidence of it on the shell for the rest of the turtle’s life.
Incidences of pyramiding are especially difficult to ignore due to the raised ridges on the affected scutes.
Since a turtle’s shell regrows so slowly, it cannot erase the pyramid effects, and the raised area will always be visible.
Turtles are attached to their shells because it serves as its skeleton, with the spine and ribs being fused to the shell.
A turtle’s shell not only provides them with defense, but it protects vital organs and other body structures inside of the turtle’s body.
A turtle should never be removed from its shell, as it is unable to live without it.