Cuticule

One speaks about cuticule for the arthropods, the plants and molluscs:

Arthropods

The cuticule indicates the external layer secreted by the skin of the Arthropode S, and more largely of the Cuticulate S (see Cuticule of the métazoaires). The cuticule does not comprise a cell. It constitutes the Exosquelette (or external skeleton) of the arthropods.

At the Insect S, it is in general made of three layers:

• the epicuticule , the most external, impermeable layer with water, it consists of Sclérotine.
• the exocuticule , the transition course made up of Protein S and Chitin. With the Mélanine which is also present there the brownish-noirâtre coloring of many arthropods gives.
• the endocuticule , a layer fine, flexible, made up of a mixture of proteins and chitin.

At the time of the moult, the endocuticule is liquefied under the action of Enzyme S secreted by glands of moult. This makes it possible the animal to be more easily detached from its old skin. After the moult, the cuticule, flexible and elastic, hardens in contact with the air.

Botany

The cuticule is a fine layer of Cutine and waxes which recovers the sheets of the plants.

Molluscs

The cuticule is an external layer of the shell, very often Vernissé E.

External bond

• cuticular differentiations of the marine planktonique Copepoda

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