In nematodes, the cuticle is the outermost layer of the tegument, immediately above the epidermis and secreted by it. It is a rigid, acellular formation (without cells), of complex structure and composed of chitin, among other substances. Its function is twofold; on the one hand it is a rigid protective and impermeable layer; secondly, it is the anchor point of the animal's muscles, so that it acts as an external skeleton (exoskeleton).
