Many people don’t know that turtles shed their shells as they grow.
Turtle shells are made of keratin, which is the same material fingernails are made of. Turtle shells grow in separate sections (or pieces), which are called scutes. Scutes grow in layers and build up outwards, with the oldest scute layers on the outside.
Turtle shell pyramiding
During periods of fast growth, such as when pet turtles are subjected to overfeeding by their owners, the shell scutes layer up quicker and more rapidly than it would naturally. This is called pyramiding, which is unhealthy and unnatural. It should be noted that some turtle species, such as some land tortoises, naturally have pyramided looking shells. In contrast, most aquatic turtles, such as red ear slider turtles, have smoother shells. It is to the smooth shelled turtle species in which pyramiding is not a normal nor healthy appearance..
Turtle shell shedding
In the process of growing new scute layers, turtles will shed their shells in time. This is a natural occurrence and not a sign of sickness or disease. Providing pet turtles the proper diet and environment, such as the proper humidity, basking areas, and temperatures will help turtles shed their shells and keep a healthy appearance.
Some turtles shed their shells in smaller pieces, some turtles shed their shells in larger pieces. You can usually tell when a turtle scute is about to be shed – the scutes look like they have air or space underneath them. Sometimes, when you press on them, water from underneath the scute will squeeze out. But that doesn’t mean a scute is about to fall off – it can still take more time before the scute will completely separate from a turtle’s shell.