A cuticle, or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non-homologous, differing in their origin, structure, function, and chemical composition.
Epicuticular wax covering the cuticle of a leaf of Hosta sieboldiana makes it hydrophobic. Water, unable to wet the cuticle, beads up and runs off, carrying dust and soluble contamination with it. This self-cleaning property is variously called "ultrahydrophobicity" or "ultralyophobicity" in technical journals. More popularly it is known as the Lotus effect.
Arthropods are invertebrates in the phylum Arthropoda. They possess an exoskeleton with a cuticle made of chitin, often mineralised with calcium carbonate, a body with differentiated (metameric) segments, and paired jointed appendages. In order to keep growing, they must go through stages of moulting, a process by which they shed their exoskeleton to reveal a new one. They are an extremely diverse group, with up to 10 million species.
Protaetia cuprea (copper chafer). Beetles are the most diverse order of arthropods.
Cicada climbing out of its exuviae while attached to tree
Long bristles (setae) of a Tliltocatl albopilosus tarantula
Head of a wasp with three ocelli (center), and compound eyes at the left and right
