Mollusca

Mollusks (phylum Mollusca, from Latin: molluscus = soft) is an animal that soft-bodied Triploblastik selomata. Into it, including all soft animals with or without a shell, such as various types of snails, kiton, shellfish, and squid and their relatives.

Mollusks are the second largest phylum in the animal kingdom after the phylum Arthropoda. Currently there are an estimated 75 thousand species, plus 35 thousand species in the fossil record. Mollusks live in marine, freshwater, brackish, and terrestrial. From the trough of the sea to the continent of high mountains, it's easy even found around our homes.

Mollusks studied in a branch of zoology called Malacology (malacology).

The body is not segmented. Bilateral symmetry. His body consists of "feet", muscular, with a growing head varies by class. Foot is used in adapting to survive in the substrate, dig and drill the substrate, or do the movement.
Size and body shape

Mollusks body size and shape vary greatly. For example, the snails are only a few millimeters in length with an oval shape. However, there is also a giant squid in the form of a winged torpedo more than 18m in length.
Structure of the body and functions

Animal body is composed of three main parts, ie legs, body, and coat.

The nervous system of mollusks consists of oesophageal nerve ring that has spread to the nerve fibers. A complete digestive system, consisting of the mouth, esophagus, stomach, intestine, and anus.

Anatomy of mollusks is relatively similar to that of vertebrates. This leads many experts estimate that vertebrates and molluscs still have a close evolutionary relationship. This is reinforced by the fact that mollusks, especially cephalopods, have well-developed brains and some of them proved to have a strong ability to remember.