What is the structure in a clam that secretes the shell?

The bivalve shell is composed of two calcareous valves. The mantle, a thin membrane surrounding the body, secretes the shell valves, ligament, and hinge teeth.

Similarly, you may ask, what controls the opening and closing of the clam shell?

Rings on the shell are “growth rings” and are an indication of the clam’s age. Use the figure at the below to locate the ANTERIOR and POSTERIOR ADDUCTOR MUSCLES. Use your scapel to cut through these two muscles so you can open the shell. These control the opening and closing of the shells.

What is the mantle of a clam?

“The mantle (also known by the Latin word pallium meaning mantle, robe or cloak, adjective pallial) is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.

What holds the two shells together in a bivalve mollusk?

Bivalve molluscs are completely enclosed by a shell made of two valves hinged at the top. A hinge ligament made of elastic protein joins the two halves of the shell together, and large adductor muscles between the two valves hold them closed.

How is the shell of a clam made?

Seashells are the exoskeletons of mollusks such as snails, clams, oysters and many others. Such shells have three distinct layers and are composed mostly of calcium carbonate with only a small quantity of protein–no more than 2 percent. These shells, unlike typical animal structures, are not made up of cells.

What produces the shell in the most mollusks?

Mollusk shells are made of a chalky material called calcium carbonate. The shell has three layers for extra strength: a tough outer layer, a chalky middle layer, and a shiny inner layer, next to the animal’s skin. The shiny layer in some bivalve mollusks is known as mother-of-pearl.

How do squid and octopus move quickly away from predators?

Octopuses and squids can swim in any direction and can alter their course quickly. Squids use fins located on their heads to propel themselves when swimming at low speeds. These fins steer and stabilize the squids when moving slowly, and wrap around the body when they move quickly, by way of jet propulsion.

Where is the palps found in a clam?

Where are the palps found and what is their function? A pair of labial palps are located at the anterior end of each set of gills. They direct the trapped food toward the mouth. Describe the movement of food from the current siphon through the digestive system of the clam.

What animal group does a squid belong to?

Squids belong to the group of mollusks called cephalopods, which include octopi, cuttlefish, etc. Under this order, there are many subcategories of squid. For example, squid that secrete luminescent ink are classified in the genus Heteroteuthis of the family Sepiolidae.

What do you call a snail’s foot?

In spite of that, a large part of a snail’s body can be seen extended outside of the shell, when the snail is crawling around. This body part is flattened at the belly side (ventrally) to form a flat crawling sole and mainly is used for locomotion. This is why it is consequently called the foot.

What class of mollusks do clams belong to?

Clams, Snails, and Squid: Phylum Mollusca, Class Pelecypoda. Pelecypods have two shells, or bivalves, that protect the soft parts of the animal. The valves are generally of equal size (except in groups like the oysters) and shape and are hinged at the back.

Do clams have a complete digestive system?

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.

What are the three body parts of a clam?

Despite their diversity, mollusks share in common a three-part body plan that includes a head, a foot and a visceral mass.

  • The Head. The mollusk’s head region contains the brain.
  • The Foot. A mollusk has a “foot,” the body’s muscular section, responsible for movement.
  • The Visceral Mass.
  • Shells.
  • What is the most intelligent group of mollusks?

    The cephalopod class of molluscs, particularly the Coleoidea subclass (cuttlefish, squid, and octopuses), are thought to be the most intelligent invertebrates and an important example of advanced cognitive evolution in animals.

    Why is the clam considered to be a bivalve?

    Clams and their relatives (oysters, scallops, and mussels) are often called bivalves (or bivalved mollusks) because their shell is composed of two parts called valves. Bivalves have a long history.

    How does a scallop reproduce?

    The bay scallop is both a male and a female. Reproduction occurs primarily in the fall as water temperature begins to drop and scallops release eggs and sperm into the water. Fertilized eggs develop into a swimming larval stage known as a veliger.

    Is the circulatory system of a clam open or closed?

    Clams have an open circulatory system; humans have a closed circulatory system. Both systems move blood throughout the organism providing exchange of nutrients/oxygen for waste products/carbon dioxide, at the cellular level.

    Why are the clams referred to as filter feeders?

    Filter Feeding. Clams are known as filter feeders because of the way they eat their food. Since they have no heads or biting mouthparts, they have to feed in an unusual way. They pull water — which also contains food particles — in through one of their syphons and into their gills.

    How does a clam get oxygen?

    They extract, or “breathe,” oxygen from the water with gills, which have large surface areas and very thin epithelia (“skins”). When the clam is filtering or “open,” water is moved over the surface of the gills by tiny cilia (small hair-like projections from the gills).

    What type of a feeder is a clam?

    The soft-shelled clam is a suspension or filter feeder. Water is brought into the clam through an intake siphon, which extends from its shell to the surface of the mud. As the water passes over the gills, oxygen is removed for respiration and small hair-like structures known as cilia trap plankton for food.

    What controls the opening and the closing of the clam’s shell?

    Rings on the shell are “growth rings” and are an indication of the clam’s age. Use the figure at the below to locate the ANTERIOR and POSTERIOR ADDUCTOR MUSCLES. Use your scapel to cut through these two muscles so you can open the shell. These control the opening and closing of the shells.

    How do clams acquire their nutrition?

    All clams are bivalve (two shells) mollusks that obtain their food by pumping water through their system and filtering small organisms from surrounding waters.

    How do bivalves open and close their valves?

    Bivalve mollusks generally have either one or two adductor muscles. Scallops and file clams can swim by opening and closing their valves rapidly by alternatingly contracting and relaxing their adductor muscles; water is ejected on either side of the hinge area and they move with the flapping valves in front.

    What is a visceral mass and what does it protect?

    Define visceral mass and tell what protects it. Visceral mass is a soft body that is covered by a protective layer called the mantle. The visceral mass protects the internal organs. Mollusks breathe by using tiny gills located in the mantle.

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