What does the pallial line indicate?
What does the pallial line indicate?
The pallial line is a mark (a line) on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle muscles were attached in life.
What is the significance of the pallial line in a bivalve?
Joining the two adductor muscle scars is the pallial line. This marks where the pallial muscles fasten the mantle to the shell. The pallial sinus, when present, marks the insertion of the muscles used to pull the siphons into the shell.
What is the function of the anterior of a clam?
At the front and rear of the animal are anterior and posterior adductor muscles, The muscle fibers run transversely, across the clam, from shell to shell, and their action is to close shut. Some bivalves have two adductor muscles, like the common clam we use here.
What is the function of the adductor muscles in the clam?
The muscles are strong enough to close the valves of the shell when they contract, and they are what enable the animal to close its valves tightly when necessary, such as when the bivalve is exposed to the air by low water levels, or when it is attacked by a predator.
What is the function of pallial sinus?
The pallial sinus corresponds to a “pouch” in the animal body that houses the siphons when they are retracted. The siphons are fleshy tubes that can be expanded for the intake and outtake of water for respiration and feeding.
What produces the Pallial line?
A mark on the inner surface of a bivalve shell caused by attachment of the mantle.
What is the function of Pallial sinus?
What is the function of the toothlike projections at the dorsal edge of the clams valves?
What is the function of the tooth-like projections at the dorsal edge of the clam’s valves? These microscopic teeth help make sure that the valves align properly while closing. To make sure that the shells form a tight seal of protection.
What type of circulatory system does a clam have?
A circulatory system such as that of the clam in which blood is not always contained within the heart or blood vessels is called an open circulatory system.
What is the function of the adductor muscle in a bivalve?
The adductor muscles contain both smooth and striated fibres, enabling sustained (‘catch muscle’) and rapid shell closure. The hinge ligament is usually external to the shell, but in many species has shifted to an internal position between the hinge teeth.
What is the inside lining of a clam shell?
What muscles open and close the clam? Describe the inside lining of the shell. Called the nacre, soft and smooth and protects the shell.
How can you distinguish a mussel from a clam?
Whereas mussels often have an oblong and thin shape, edible clams tend to be stouter, rounder, and fatter. Clams can grow to be much bigger than mussels with the non-edible giant clam being able to grow to more than 500 pounds and 4.25 feet long (via The Monterey Bay Aquarium).
Where is the pallial line on a clam?
Pallial line. In clams with two adductor muscles the pallial line usually joins the marks known as adductor muscle scars, which are where the adductor muscles attach. The position of the pallial line is often quite clearly visible as a shiny line on the slightly more dull interior surface of the bivalve shell.
What is the pallial line on a bivalve mollusk?
Pallial line. The pallial line is a mark (a line) on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle muscles were attached in life. In clams with two adductor muscles the pallial line usually joins the marks known as adductor muscle scars, which are where the adductor muscles attach.
What is the pallial line?
The pallial line is a mark (a line) on the interior of each valve of the shell of a bivalve mollusk. This line shows where all of the mantle muscles were attached in life.
What does a hard shell of a clam look like?
The shell of the Hard-Shelled Clam ( Mercenaria mercenaria ), with the muscle scars, pallial line, and pallial sinus outlined on an inside view (upper right). A natural pearl from this species is at lower left.
