Tortoises have a hard outer shell, not just scales like most reptiles. They’re born with shells that increase in size to accommodate their age-related growth and physical development.
No, a tortoise can’t survive without its shell. Their bones, nerves, blood vessels, and muscles are fused to their shells, so shell loss or removal would kill a tortoise because it’s part of its skeletal structure.
The shell is strong and can heal from breakage, but being dropped from a height and bad falls can cause permanent damage. A tortoise’s well-being is reliant on the structural integrity of its shell.
Are Tortoises Born with Their Shells?
The shell forms along with the tortoise inside the egg. The shell is fully formed when the baby tortoise (or hatchling) arrives, albeit much softer than an adult tortoise’s shell.
Tortoises don’t molt and grow a new shell, keeping the same shell they’re born with for their entire lives. The shell grows along with the rest of the body, provided the tortoise stays healthy.
How Does The Shell of A Tortoise Grow?
While all tortoises have different-sized shells, they all fulfill the same basic function. The shell protects the tortoise from harm, so a healthy tortoise will have a healthy shell.
A tortoise’s shell consists of the plastron (underside or ventral shell) and the carapace (top or dorsal shell). Then, a bridge fuses the plastron and carapace.
The shell comprises many small bones covered by keratin (also known as scutes).
Tortoises don’t accommodate growth by shedding their scutes. As the tortoise’s size increases, the epithelium produces further keratin layers underneath, leading to growth rings, thus expanding the shell.
A tortoise’s marginal scutes affect the shape of the shell. The shape of the shell may change slightly as the tortoise grows, but its underlying structure remains unchanged.
A suboptimal diet or poor husbandry could lead to metabolic bone disorder (like pyramiding) or shell rot.
Can A Tortoise Live Without A Shell?
Tortoise shells are part of the body. The carapace is connected to the spine, while the plastron supports the ribs and other bones.
Without the shell, the entire skeletal structure would collapse. A tortoise without a shell is like a human without a skeleton; it can’t function or survive without one.
Aside from the skeletal structure, the shell is a vital part of the capillary and nervous systems.
The underlayer of the shell is made of bone, which protects the internal organs.
What Does A Tortoise Look Like Without A Shell?
Many people believe that tortoise shells are separate from the rest of the body.
It doesn’t help that many of us grew up watching cartoons where a tortoise or turtle removes its shell, revealing a smooth, green body underneath. However, this isn’t an accurate representation.
Inside a tortoise’s shell, you’ll find its organs, muscles, blood, and bones.
Because tortoises’ shells are connected to the rib cage and spine, you would immediately be met by the internal organs if the shell were opened.
Why Do Tortoises Have Shells?
Tortoises are natural foragers who survive by being defensive more than offensive. They’ve evolved to hide in their shells and dig tunnels to avoid extreme weather and predation.
Tortoises have shells for the following reasons:
Helps with Digging
The oldest chelonian species had a wide ribcage, not a carapace. Developmental biologists believe that the bone structure eventually grew and morphed into the iconic chelonian shell.
Experts theorized that they evolved with shells to make digging easier because how the shells are shaped means that they anchor the tortoise’s limbs to have an easier time burrowing.
Protection from Threats
Tortoises can’t detach themselves from their shells but can hide in them. This way, they can protect themselves from predators when attacked and while brumating.
Keeps Them Cool and Hydrated
Tortoises are cold-blooded (ectothermic) animals, unable to self-regulate their body temperature.
When the temperature gets too hot or the air is too dry, tortoises shade themselves from their environment by hiding in their shells.
This ensures they maintain their optimal body temperature and don’t lose further moisture when the conditions are wrong.
Storing Nutrients
According to Food Analytical Methods, tortoises use their shells to store nutrients. A strong, healthy shell enables them to survive brumation and when food is scarce.
Is My Tortoise Losing Its Shell?
A tortoise can’t lose its shell without dying.
Tortoises shed skin on their shell as they grow, but they’re not losing their shell. If you notice that the shell is deformed, the tortoise has metabolic bone disease (MBD), or the shell is broken.
Metabolic bone disease is an umbrella term that describes a disorder that causes the shell to soften up or grow abnormally. If the disorder is severe, it may seem like the tortoise is losing its shell.
Take the tortoise to the vet if its shell is cracked, as they don’t molt and grow new shells. So, if it does lose a piece of its shell, it’ll be at risk of bacterial infection (sepsis) and even death.
If you notice a tortoise’s shell flaking off, this is normal. Skin and shell shedding is common, especially in growing tortoises. You should only be concerned if large pieces of the shell fall off.
Can a Tortoise Be Removed from Its Shell?
Under no circumstances should a tortoise ever be removed from its shell, as doing will cause extreme pain before killing them. A tortoise’s shell is fused to its ribcage and spine.
The shell is full of nerve endings, and the tortoise will feel everything if you try to pull it out. Due to the blood vessels in the shell, the tortoise will bleed to death.
Certain metabolic bone diseases can soften the shell and deform it to the point where it seems like the tortoise can slip out of it.
However, no matter how deformed the shell is, it’s still attached to the internal skeletal structure. So, severe shell deformation needs to be addressed before the tortoise dies.
Can A Tortoise Regrow Its Shell?
Tortoises are born with shells, and that’s the shell they keep for the rest of their lives. If the shell is cracked and the damage is serious enough, the tortoise won’t recover because shell regrowth is impossible.
However, tortoises can heal their shells as long as the layer under the upper keratin layer isn’t damaged.
According to the Italian Journal of Zoology, tortoises develop scars at the point of injury. It was noted that naturally-occurring shell injuries were mostly observed toward the back of the carapace.
Surface cracks on the upper layer of the shell can heal after a few weeks, but anything deeper than that may require surgery to ensure the tortoise’s internal organs aren’t compromised.
Even a surface-level shell crack can become fatal if not treated properly because bacteria can enter the crack and compromise the shell, causing further cracks until the shell deteriorates.
