Page "Abalone" Paragraph 5

The shell of abalone are convex, rounded to oval shape, and may be highly arched or very flattened.

The shell is generally ear shaped, presenting two to three whorls.

The last whorl ( known as the body whorl ) is auriform, meaning that the shell resembles an ear, giving rise to the common name " ear shell ".

The abalone shell has a series of holes near the anterior margin, that are respiratory apertures for the venting of water from the gills and for releasing sperm and eggs into the water column at the appropriate time.

These holes collectively make up what is known as the selenizone which form as the shell grows.

The older holes are gradually sealed up as the shell grows and new holes form.

Each abalone species has a typical number of holes in the selenizone which remain open.

There are four to ten of these holes, depending on the species.

Abalone have no operculum.