Does a tortoise have a type of exoskeleton? Do they shed their shells?

Question

My husband seems to think that a tortoise will shed it's shell, I don't think this is correct but I thought I'd ask.

Answer 1

A tortoise has an internal skeleton, so the shell is not an exoskeleton. It's not like crabs or lobsters for example, which shed thier shells as they grow biiger. A tortoises's shell grows with the tortoise

Answer 2

no, they don't shed their shells, and they have a skeleton inside of their shell, too, but their skeletons are attached to the inside of their shells so no they don't shed them.

Answer 3

tortoises are shielded from predators by a shell. The top part of the shell is the carapace, the underside is the plastron, and the two are connected by the bridge. The tortoise has both an endoskeleton and an exoskeleton.

As a shell grows, the number of scutes generally does not change, but their size does. In some turtles, old scutes are shed and replaced by larger, new ones. In other species, including box turtles, tortoises, and wood turtles, scutes enlarge in diameter as new keratin is laid down. The "growth rings" in scutes have been used be some experts to help determine the age of a turtle. Age estimation based on growth layers, however, can be erroneous for several reasons:

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      Redfooted Tortoise

      Some turtles produce multiple growth zones per year.

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      Growth is determined by changes in the environment (seasons), so age determination by examination of growth rings would be more accurate in wild turtles, than those kept in environments which do not change significantly.

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      Growth layers may wear with age, so older turtles may be estimated to be younger than they really are.

Retained scutes: "Dysecdysis" is the term to describe the condition in which an old scute is retained and not shed properly. This condition is often associated with poor husbandry, and may occur if the turtle has not been able to dry off or bask sufficiently to lose its old scutes. Retained scutes often become infected. A turtle with dysecdysis should be examined by a veterinarian.

Sulcata tortoise with malformed scutes

Metabolic bone disease and pyramiding: A turtle with an inadequate calcium or Vitamin D intake, inadequate exposure to ultraviolet light, or disease of the liver, kidneys, or parathyroid glands may develop metabolic bone disease. This causes softening and malformation of the bones. The shells of turtles with metabolic bone disease are often deformed, with the rear area of the carapace pulled downward, and the marginal scutes pulled upward. Tortoises with metabolic bone disease may develop pyramid-shaped scutes. Metabolic bone disease can be fatal; turtles suspected of having this disease should be examined by a veterinarian. Husbandry and diet changes may be able to correct the calcium imbalance, but deformities are generally permanent.

It has also been found that African Sulcata tortoises raised in dry conditions are more likely to develop a shell abnormality called "pyramiding," which is an abnormal hump-shape of the scutes. Tortoises raised in environments with 45-99% humidity had less abnormal shell growth than those raised in drier conditions.

Renal failure and sloughing of scutes: Although rare, renal failure in a turtle has been reported to cause a turtle to slough his scutes. Kidneys help to maintain the proper calcium and phosphorous levels in the blood. If the kidneys fail, the phosphorous level in the blood increases. The turtle's body attempts to compensate by moving calcium from the bones into the blood stream. The bones in the shell, then, can become soft.

Ulcers: Ulcers of the shell may be superficial or deep, and may be termed "shell rot." Ulcers are generally a result of poor husbandry. Turtles with ulcerative shell lesions should be examined and treated by a veterinarian, as the ulcers may become infected and penetrate through the shell. The shell will need to be cleaned daily, and dead tissue removed. Topical and/or injectable antibiotics are required in the case of bacterial infections. Deep ulcers may need to be repaired through surgery and the application of acrylic or fiberglass material. In a disease called "septicemic cutaneous ulcerative disease," or SCUD, ulcers may be seen on both the shell and legs. This condition is often associated with the bacteria, Citrobacter freundii.

Injuries: Injuries due to trauma or burns can cause pain, can lead to infections, and may cause misshapen scutes as they heal. Although the shell has a remarkable ability to repair itself, any turtle with an injury to the shell should be examined by a veterinarian immediately. Fatal infections can occur.

Other causes of deformed scutes: Scutes may also be deformed in size or shape due to genetics or improper egg incubation.

The shell of a turtle is an amazing adaption which has allowed turtles to exist for millennia. The proper diet, husbandry, and care are vital to maintain a healthy shell

Answer 4

OK, lets cut through all of this...

A tortoise's shell is made of up of several layers. The innermost layer is bone and is the tortoise's skeleton- ribs, sternum, some parts of the pelvis, and spinal column. He CANNOT shed this element.

On top of that is a layer of modified skin, so the skeleton is inside the tortoise's skin- no bone on the outside.

On top of the skin are several layers of growing scales called 'scutes', Scutes are similar to your fingernails. Some species of tortoises and many species of turtles shed the outer scute layer as the animal grows, others just add more material around them to make the distinctive growth rings.

Thus, unlike cartoon turtles, real turtles cannot every remove their shells and survive.

Answer 5

No, they cannot shed their shells, but they do shed the skin of their necks and legs.  The ribs and backbone of tortoises and turtles are actually fused to the underside of the ventral (upper) shell.  Because of this, and the fact that the shell actually forms the upper and lower skins of the animals, they "do" have an endoskeleton like all vertebrates.  Only invertebrates, like Arthropods (insects, spiders, crabs, etc), have exoskeletons.  And this skeleton is not actually a skeleton, but a shell to protect the internal organs.

Answer 6

No, it doesn't shed.

No more than our fingernails do.