Mise en place de l'epicuticule chez le crabe Carcinus maenas

The epicuticle of the crab Carcinus maenas consists in three distinct layers: the fibrous surface coat, the cuticulin layer and the inner epicuticle. Short segments of the cuticulin layer are first deposited at the top of dense plaques of the ectodermal cell membrane. Their assembling gives rise to a five-layered continuous structure of about 37 nm thick. Afterwards, the inner epicuticle is added inside close to the cuticulin layer but dense plaques are not concerned with the phenomenon. The deposition of the fibrous surface coat outside to the cuticulin layer takes place only during late postmolt stages (D2-D3). In mineralized cuticles, this typical epicuticle structure persists during all intermolt long.