Why do clams have two shells?

Answer 1

This is from Wikipedia:

Bivalves have a shell consisting of two asymmetrically rounded halves called valves that are mirror images of each other, joined at one edge by a flexible ligament called the hinge.

Answer 2

Answer

Clams are not actually known as the primary producers of pearls although they can and do produce pearls. Clam pearls are known as calcareous concretions, not as nacreous pearls. Clams do not produce nacre. Mollusks from the family Bivavlia are the primary pearl producers, especially mollusks from the genus Pinctada. Contrary to popular belief, a pearl is not created by a grain of sand. This is a widely accepted urban legend. A pearl is most often created when a parasite burrows through a mollusk's shell and into the mantle tissue of the host. The defensive reaction of the mollusk is to grow a sac around the intruder. This is known as the pearl sac. The lining of this sac is made up of nacre-producing cells known as epithelial cells. These cells produce a chemical compound of aragonite and calcite (a calcium carbonate polymorph) which is laid down upon the intruder in the form of platelets. These platelets are commonly known as nacre. Nacre is the pearl.
Pearls grow in pearl-producing mollusks. Natural pearls occur when a mollusk's mantle tissue becomes damaged either by parasitic intrusion or damage to the shell. The mantle contains epithelial cells, which are responsible for the nacre deposition on the inside of the shell. If these cells become dislodged when the mantle is damaged, they may continue to deposit nacre within the body of the mollusk, creating a pearl.

A grain of sand neverproduces a pearl. This is a myth.

Answer 3

Clams are called filter feeders because in order to eat they must filter their food from the water.

GPH

Answer 4

they are members of the class bivalvia, one of the requirements being that they have two shells. they just evolved this way, the shells serve as a means of protection and shelter.

Answer 5

clams have shells to protect themselves. just like a snail for example.

Answer 6

Because bi means two (as in a two wheeled bicycle) and the clams and oyster have to halves to their shells.

Answer 7

It has two valves, hence bi....

Answer 8

polychaeta