Turtle and Tortoise Shells

Healthy and Unhealthy Turtle and Tortoise Shells

Little Turtle - Alabama Cooter
Little Turtle - Alabama Cooter. Megan and Kevin

Turtles and tortoises have shells that vary in size, color, and shape by species but all species have something in common - their shells are hard and protective. But what does a normal shell look like? Is it smooth or should it have peaks? Find out the answers to these questions and more here.

The Shell

Turtles and tortoises have a carapace (the top or dorsal shell) and a plastron (a bottom or ventral shell), both of which should always be hard (unless it is a very young turtle or a species of turtle that always has a soft shell).

Both parts of the shell are connected to protect the turtle's organs and majority of it's body.

The carapace is the most visible part of the turtle shell and concurrently the side of the shell that most problems are associated with. The plastron is more susceptible to infections since it is on the dirty ground regularly but it can also have other problems like the carapace.

The turtle shell is made up of visible sections referred to as scutes. Scutes are similar to hair and nails since they are made up of keratin. These scutes will normally shed off as individual sections as the turtle grows and sheds his skin but the bone underneath the scutes should never be exposed in a healthy turtle. The turtle's spine and ribs are attached to the bone that the carapacial scutes protect.


Turtle shells vary from species to species. Some tortoises and turtles naturally have peaks to their shells, such as the Indian Star Tortoise, but most do not.

Pyramiding refers to the abnormal shape that the individual sections (scutes) form in the shape of a pyramid or raised peak. It is strictly a husbandry issue and occurs with chronic malnutrition or inappropriate lighting. Wild turtles and tortoises do not get this problem.

Too much or too little of a specific dietary requirement, no UVB lighting, and a lack of calcium or Vitamin D can all aid in the creation of pyramids on your turtle's shell.

These malformations are completely avoidable by providing appropriate foods, lighting, and environments for your turtles. These pyramids will remain for the life of your turtle, even after correcting the problems with the husbandry.

Shell Rot

"Rot" is a term that reptile enthusiasts use to refer to an infection somewhere on the body. Shell rot obviously refers to an infection of the shell. Both the carapace and plastron can get shell rot on sections of them.

Shell rot is usually acquired from dirty environments, such as dirty water (learn how to keep the water in your aquatic turtle tank clean) or moldy bedding. It occurs when bacteria starts flourishing on the shell of a turtle and will eventually cause it to have the appearance of rotting fruit with small pits and divots or a moth eaten appearance. Soft spots may start to form or even have areas of discharge. Very bad shell rot will cause entire scutes to fall off, exposing the bone underneath.

Shell rot needs aggressive antibiotics to treat and will take a long time to heal.

Contact your exotics vet if you think your turtle has an infection.

Septicemic Cutaneous Ulcerative Disease

This is a serious disease that is commonly referred to as SCUD that can start as an infection from some sort of trauma or wound combined with poor husbandry. It will eventually affect the liver and other organs due to the bacteria that enters the bloodstream from the wound. You should get your turtle or tortoise checked out by an exotics vet if he ever has any wound or trauma.


Individual scutes should naturally shed off and expose only new scutes underneath. If scutes are falling off and exposing the bone there is most likely a serious infection or some trauma that has occurred to the shell.

Metabolic Bone Disease

MBD is a result of inadequate calcium, Vitamin D, and UVB rays. It causes bones to lose their density and shells to eventually soften or become malformed.

All in all, turtle shells should typically be free of algae, fairly smooth and even, and hard. There are always exceptions to the rules but if your turtle or tortoise's shell ever looks strange to you be sure to get him checked out by his vet.