Nematodes are roundworms characterized by a tough outer cuticle, unsegmented bodies, and a fully developed gastrointestinal tract.

The algae are generally absent in the hair of young sloths, and may also be absent in particularly old individuals, where the outer cuticle of the hair has been lost.

Now that the slugs have developed this outer cuticle the parasite's environment is the host.

In some species, the mouth includes an eversible capsule, often bearing teeth formed from the outer cuticle of the body wall.

As eggs hatch into the first larval stage, P. terraenovae begins feeding and increases in size, limited by its chitinous outer cuticle.

On the following day the strips of bark are scraped so as entirely to remove the outer cuticle.

Enzymes are secreted to digest the inner layers of the existing cuticle, detaching the animal from the outer cuticle.

The gregarious larvae bore into the cactus pad through a single entry hole by chewing through the tough outer cuticle of the cladode.

Keratella cochlearis has an oval lorica, a shell-like protective outer cuticle.

An outer cuticle which lines the hair is made up of overlapping scales, and this helps produce a barrier to normal decomposition.