How do you mark turtle shell for identification?

To mark a turtle shell for identification, researchers typically use non-toxic, waterproof paint or a unique numbering system etched into the shell using a gentle tool. Marking is often done on the marginal scutes, which are the outer plates of the shell, to minimize impact on the turtle. It's essential to ensure that the marking does not harm the turtle or interfere with its natural behavior. Additionally, keeping detailed records of each marked turtle and its corresponding identifier is crucial for effective monitoring and study.