How and why sea turtles itch

Contrary to myth, the shell of a sea turtle (Cheloniidae) is not a lifeless piece of armor, but a living part of the body, fused with the ribs and spine.

It is permeated with numerous nerve endings and blood vessels. Turtles are acutely sensitive to any touch, vibration, pressure, and, consequently, itching. Sea turtle shells are often infested with algae, barnacles, and barnacles. If these become too numerous, they increase water resistance, slow the turtle down, and can literally eat into the bony plates, causing severe discomfort. Scratching helps scrape off these parasites. As the turtle grows, the old keratin scales (scales) of the shell begin to gradually peel off. This process causes itching, and friction against hard underwater objects helps speed up the removal of dead tissue. In the wild, sea turtles even find special "cleaning stations" on coral reefs where they scratch themselves on the ledges.