Patella aspera Patella aspera Patella aspera is a species of limpet, a type of sea snail in the family Patellidae. Long considered to be a subspecies of "Patella ulyssiponensis", genetic evidence supports its recognition as a separate species. It is native to Macaronesia. It is known by the common name Azorean limpet, and its local name is "lapa brava". This species lives on rocks in the shallow sublittoral and intertidal zones. It is a keystone species which is of ecological importance as a grazer. It is collected for food. Overharvest is the main threat to the species, which has faced population declines
Composition of the human body viewed on an atomic and molecular scale as shown in this article. The estimated gross molecular contents of a typical 20-micrometre human cell is as follows: Body composition can also be expressed in terms of various types of material, such as: There are many species of bacteria and other microorganisms that live on or inside the healthy human body. In fact, 90% of the cells in (or on) a human body are microbes, by number (much less by mass or volume). Some of these symbionts are necessary for our health. Those that neither help nor harm humans are called commensal