Why does fresh crab legs feel slimy?

Fresh crab legs may feel slimy due to the presence of a thin layer of mucus that coats the shell to protect the crab's body. This mucus helps prevent the crab from drying out and protects it from bacteria and other contaminants in the water. Additionally, the sliminess may be attributed to the natural lubrication produced by the crab's body to aid in movement and protection.