Where is clams heart located

The mollusks are mostly aquatic but are found both in fresh water and in the ocean. A few mollusks snails and slugs are terrestrial. Since the phylum is so diverse, most of this discussion will focus on the clam, an aquatic mollusk. Clams, like sponges, are filter feeders.

The soft body of the clam is protected from predators by a two-parted shell that is hinged. The shell is produced by a tissue called the mantle that is adjacent to the shell. The clam has a pair of very large gills, and the surface of the gills is covered with cilia.

The cilia beat in a coordinated fashion, and the movement of the cilia cause water to move into and through the clam. Food-containing water enters through the incurrent siphon and passes over the gills.

The gills produce a sticky, glue-like material called mucus. Food small organisms and food particles becomes trapped in the mucus. The cilia are also responsible for transporting the trapped food to flap-like structures called labial palps.

The labial palps gather the food and place it into the clam's mouth. After water passes over the gills, it exits the clam through the excurrent siphon located next to the incurrent siphon.

Filter feeding mollusk process quite a large amount of water. An average oyster filters three liters of water an hour. Clams use their muscular food for digging into the sand or soil forming the bottom of the body of water in which the clam lives.

The movement of clams is quite limited, and these are sedentary animals. The nervous system of clams consists of three pairs of ganglia connected by nerve cords. Nerves connect the ganglia and nerve cords to sensory cells. Different cells are specialized for various functions.

Some sense touch. These are located at the edge of the mantle. Light sensors are located on the siphons, and osphradia chemical sensors are located on the incurrent siphon. Clams and all mollusks have a complete digestive system. It consists of a mouth where food is ingested, a short connecting tube called the esophogus, a stomach which temporarily holds food, and an intestine where food digestion and absorption takes place. Figures 2a to 2e.

Histological sections illustrating details of the heart-kidney complex. Vacuoles within some cells of the glandular distal region of the kidney contain crystal-like inclusions.

These inclusions are most evident when observed in a fresh tissue preparation Fig. Presumably, these are concretions concrements held within lysosomal vacuoles. Secretion of the accumulated concretions occurs by apocrine discharge into the kidney lumen. Large extracellular masses formed from the concretions are carried outside the body Morse and Zardus through the kidney openings nephropore into the mantle cavity Fig.

Figure 3. An unstained wet mount squash of the glandular region of the kidney of a juvenile geoduck clam that illustrates the crystal-like inclusions arrows , some of which appear to be in vacuoles. A pair of muscle bands that pass through the left and right ventral regions of the kidney labeled rm in Fig.

Andrews, E. Excretory Systems of Molluscs. In: The Mollusca. Volume 11, Form and Function. Edited by E. Trueman and M. Academic Press, San Diego. Barnes, R. Invertebrate Zoology, 2nd ed. Saunders Company, Toronto, pp. Eble, A. Chapter 4.

Anatomy and histology of Mercenaria mercenaria. In: Biology of the Hard Clam. Edited by J. Kraeuter and M. Elsevier Science, Amsterdam. Martin, A. Edited by A. What are the functions of the heart and kidney in clams? Mandira P. Sep 1, Heart has paired auricles but single ventricle. Heart is enclosed within a pericardial cavity. Paired U-shaped kidneys are connected to pericardial cavity on one end and the opposite ends open in mantle cavity.

Ultrafiltration of haemolymph takes place in pericardial glands, also called Keber's organs. These are present on the auricular wall of heart. Accumulated waste is deposited in pericardial cavity.