The Different Parts of Clams

Shell

• Clams live inside two shells that are forced together by a hinge ligament made up of intermeshing teeth. The umbo is located directly above the hinge and is the first part of the shell to form. The shell consists of calcium carbonate that is secreted by the clam.

Adductor Muscles

• Clams are able to close their shell tightly with adductor muscles. These muscles contract when the clam feels threatened or if the water conditions are poor. A section of the muscle, called the foot, can reach outside the shell and allow the clam to burrow. Each clam has two adductor muscles, one located on either side of the inside of the shell.

Gills

• The gills account for a portion of the clam's respiratory system. The cilia that is present on the gills and mantle generates a current that sucks water through the siphon and into the space that surrounds the gills. The water then escapes through the excurrent siphon. During this process, the gills allow the clam to breathe and filter food particles. The food is collected by the cilia, which are hair-like structures, and transferred for consumption. The clam's mantle also serves as a system that assists in breathing.

Labial Palps

• Food is moved from the labial palps, which act as an intake valve, where it is sorted into nutrients and waste. The nutrients move on to the mouth. The waste, consisting of silt and phytoplankton, is deposited at the surface of the mantle, which is the outer meat of the clam. At the mantle, the waste is turned into balls coated with mucous. Meanwhile, the food travels through the mouth and then into the esophagus where a multi-chambered stomach awaits with several passageways and sacs.

Heart

• The clam's heart pumps blood through sinuses, which are proportionately large spaces in the body. Veins then collect the blood from the sinuses and return it to the heart. The heart is located just behind a section of mantle that is located at the hinge.

Stomach

• The stomach sorts the food into digestible and indigestible particles. The digestible material is broken down with enzymes that are generated by the digestive gland, which surrounds the stomach and intestine and is soft and grayish green. The indigestible material passes to the intestine and then through the anus.