adductor muscles (noun) | a pair of muscles that close the two valves of a mussel shell. Each muscle extends from the left valve to the right valve, one in the anterior part of the shell and the other in the posterior part. |
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umbo (noun) | the raised portion of the dorsal margin of a shell, also called the beak. |
Is the UMBO the oldest part of the shell?
Locate the umbo, the bump at the anterior end of the valve. This is the oldest part of the clam shell.
What is a UMBO definition?
Definition of umbo
1 : the boss of a shield. 2 : a rounded elevation: such as. a : an inward projection of the tympanic membrane of the ear. b : one of the lateral prominences just above the hinge of a bivalve shell.
What are the 4 types of bivalves?
Bivalves include clams, scallops, oysters, and mussels. As their name implies, they have two parts of their shell, which can open and close.
How is the UMBO important to bivalves?
It usually contains the valve’s beak, the oldest point of the valve, and its degree of prominence and its position relative to the hinge line are sometimes helpful in distinguishing bivalve taxa. … Umbo is also in use in anatomic descriptions of brachiopods, for the origin of growth of the valves.
What is the covering around the clam heart called?
The pericardial area, this is the dorsal surface that the intestine passes through. Why are clams referred to as “filter feeders”? They filter plankton out of the water and trap it and direct it to their digestive tracts.
On which side of the UMBO is the anterior portion?
Recall that the umbo is near anterior end. The posterior of the clam shell is at the opposite end. In reference to the clam shell, dorsal is the side, or edge, with the umbo.
What is the Incurrent siphon?
incurrent siphon. a tube through which water enters the body of a bivalve. mantle. in mantle, a layer of tissue that covers the body of many invertebrates. mantle cavity.
What is UMBO of tympanic membrane?
The apex of the cone, where the tip of the malleus is attached, is called the umbo. The tympanic membrane faces downwards and forwards. This is a true lateral view of it. … When sound waves strike it, the tense part of the tympanic membrane vibrates.
What is the hinge ligament?
A hinge ligament is a crucial part of the anatomical structure of a bivalve shell, i.e. the shell of a bivalve mollusk. … The ligament is made of a strong, flexible and elastic, fibrous, proteinaceous material which is usually pale brown, dark brown or black in color.
What muscles are responsible for closing the bivalve shell?
The adductor muscles are what allow the bivalve to close the shell tightly.
What is the definition of siphons?
1 : a bent pipe or tube through which a liquid can be drawn by air pressure up and over the edge of a container. 2 : a tubelike part especially of a mollusk (as a clam) usually used to draw in or squirt out water. siphon. verb. siphoned; siphoning.
What are 3 types of mollusks?
The three major groups of mollusks are gastropods, bivalves, and cephalopods (SEF ul o pods). The largest group is the gastropods. These are mollusks like snails and slugs that have just one shell or no shell at all. Gastropods creep along on their broad foot.
Is squid a bivalve?
includes clams, snails, slugs, nudibranchs, squid, octopuses, tusk shells, chitons, and many others that are all generally called mollusksMollusk: … A member of the phylum Mollusca; also spelled mollusc (most especially in the United Kingdom)..
What is the classification of bivalve?
Bivalvia Temporal range: | |
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Kingdom: | Animalia |
Phylum: | Mollusca |
Subphylum: | Conchifera |
Class: | Bivalvia Linnaeus, 1758 |
What is the function of the elastic hinge in bivalves?
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. When the shell is closed, the top part of the hinge ligament is stretched and the lower part is compressed.
Do bivalves show Cephalization?
Bivalves are a bit of an exception to the cephalization that characterizes most mollusks. Bivalves don’t have a head. They feed by filtering out food from the water in which they live. They actually eat with the same structure used for breathing: the gills.
What is an apex or UMBO?
The apex of a valve of a bivalve shell is the area around what is most commonly the umbo or beak. In some species the embryonic shell or prodissoconch may be present at the apex of each of the two valves.
Why is a clam called 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. … Some bivalves, such as oysters, do not have symmetrical valves.
Why are 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.
What is the function of a siphon in a clam?
Siphons in molluscs are tube-like structures in which water flows (or more rarely in which air flows). The water flow is used for one or more purposes such as locomotion, feeding, respiration, and reproduction.
What sides in the siphon on the anterior or posterior?
The siphons are at the posterior end. If the siphons are not visible, determine which is the ventral side by using the umbo. The umbo is the bump on the top of the shell. It leans toward the anterior end.
What are bivalve shells made of?
The bivalve shell is made of calcium carbonate embedded in an organic matrix secreted by the mantle. The periostracum, the outermost organic layer, is secreted by the inner surface of the outer mantle fold at the mantle margin.
What tissue covers the soft body of a clam and secretes the shell?
mantle, also called pallium, plural pallia, or palliums, in biology, soft covering, formed from the body wall, of brachiopods and mollusks; also, the fleshy outer covering, sometimes strengthened by calcified plates, of barnacles. The mantle of mollusks and brachiopods secretes the shell in species that possess shells.
What organisms have Incurrent and Excurrent siphon?
A tunicate is a baggy animal that is more commonly known for living on the sea floor, where it sucks in water through an incurrent sipon, filters the tasty bits, then ejects the water through an excurrent siphon. This gives tunicates their common name: sea squirts.
What does a squid’s siphon do?
The funnel, or siphon, is a muscular structure located on the ventral surface of the mantle. It has several functions, including respiration and discharge of wastes. The colossal squid also uses the funnel to help it move in the water.
What is the siphon of an octopus?
Octopuses pull water into their mantle cavities and then squeeze it out through the siphon (also called a funnel) at the front of their mantles to both swim and steer.
How fragile is the eardrum?
The eardrum membrane is extremely delicate and can be vulnerable to damage. Ruptured eardrums are a common response to overpressure that can lead to hearing loss, including any situation with loud noises or extreme changes of pressure.
What is Stapedius muscle?
The stapedius muscle is the smallest striped muscle of the human body and contracts reflexive in response to acoustic stimulation. The stapedius muscle puls the neck of the stapes in the direction of the stapedius tendon. … The stapedius reflex shows bilateral interactions and its center is located in the brainstem.
What protects the tympanic membrane?
The outer ear is composed of the pinna, or ear lobe, and the external auditory canal. Both structures funnel sound waves towards the ear drum or tympanic membrane allowing it to vibrate. The pinna is also responsible for protecting the ear drum from damage.
What does the hinge ligament allow?
Hinge joints allow the movement of certain parts of the body in one plane. There are hinge joints in the fingers, toes, knees, elbows, and ankles. Although hinge joints are stable, people can still dislocate a bone in them. Osteoarthritis is common in hinge joints.
What is the hinge ligament structure known as in mussels?
Hinge teeth are part of the anatomical structure of the inner surface of a bivalve shell, i.e. the shell of a bivalve mollusk. … To make this possible, in most cases the two valves are articulated using an arrangement of structures known as hinge teeth (often referred to collectively as the “dentition“).
What muscles open and close clams?
Have you ever tried to open a clam by hand? It’s very difficult because the clam has two powerful lateral muscles called “adductor muscles” that allow the clam to close shut.
How do bivalves open and close their shells?
Bivalve mollusks generally have either one or two adductor muscles. … When the adductor muscles relax, the valves of the shell are automatically pulled open to some extent by a ligament, which joins the valves together and which is usually located on the hinge line between the umbos of the shell.
How does a bivalve take in oxygen and food?
Bivalves are adapted to breathe underwater by using gill membranes. In function, gills are like your lungs. They are membranes that take in oxygen and give off carbon dioxide. … The food particles in the water get stuck in mucus that coats the surface of the gills and mantle.
Why do bivalves open their shells?
Some clams will use those muscles to open their shells when they are in search of food. These filter feeders eat and breathe through a tube-like part of their body called a siphon, which sticks out from the top of their shells.
What does siphon mean in Vampire Diaries?
Siphoning is the distinct ability of siphoners and witch-vampire hybrids to absorb or consume magic from magical objects and other supernatural beings albeit temporarily.
Where is siphon used?
At sea level, water can be lifted a little more than 10 metres (33 feet) by a siphon. In civil engineering, pipelines called inverted siphons are used to carry sewage or stormwater under streams, highway cuts, or other depressions in the ground.
What is siphon in 1v1 lol?
Siphon in Fortnite is a mechanic that lets you instantly heal health or shield upon eliminating an opponent. Depending on the game mode, it heals you from 25 to 50 points of health, and if you need to recover fewer health points than that, the extra health is converted into shield.
What are the 4 major molluscs?
The four major groups of mollusks (phyla Mollusca) are: 1) chitons; 2) gastropods, including snails, slugs (mostly marine, but some freshwater), and nudibranches.
What is a group of mollusks called?
Cephalopoda. The class Cephalopoda is a remarkable group of mollusks comprising roughly 800 living species that includes the largest known invertebrate: the colossal squid.
Is a scallop a cephalopod?
Clams, Oysters, and Scallops are bivalve mollusks and are a familiar food source. These three animals pull their shells closed by contracting powerful muscles near the hinge.