The radula is unique to the molluscs, and is found in every class of mollusc except the bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth. Within the gastropods, the radula is used in feeding by both herbivorous and carnivorous snails and slugs.
What is role of radula in molluscs?
The radula is a file-like rasping organ found in molluscs. It helps in scraping food. It also used for creating depression in rocks.
What phylum has a radula?
The radula is present in all molluscs except bivalves, and only in molluscs.
What is a radula What does it look like in a gastropod?
As for the radula itself. it is a ribbon-like structure covered with many denticles (tiny teeth). It is movable over the odontophore and is also controlled by muscles. The feeding behavior of marine snails include some that are herbivores, detritus (debris) feeders, scavengers and predatory carnivores.
Do Chitons have a radula?
The mouth is located on the underside of the animal, and contains a tongue-like structure called a radula, which has numerous rows of 17 teeth each. The teeth are coated with magnetite, a hard ferric/ferrous oxide mineral. The radula is used to scrape microscopic algae off the substratum.
What is a radula Polyplacophora?
Summary. The major lateral radula teeth of chitons (Mollusca:Polyplacophora) are one of the hardest and most wear resistant biomineralized tissues known to date. Their hierarchical architecture makes ingenious use of magnetite and a variety of other biominerals.
What is the importance of radula?
The radula is a file-like rasping organ found in molluscs. It helps in scraping food. It also used for creating depression in rocks.
What is radula Ncert 11?
The radula is present in the buccal cavity of a mollusc. It is a minutely toothed, chitinous ribbon, that is usually used for scraping or cutting food. Within the gastropods, the radula is used in feeding both by herbivorous and carnivorous snails and slugs.
What is regular in Mollusca?
Radula is a file-like rasping organ found in Molluscs. It helps in scraping and scratching the food before it enters the Oesophagus. They are also used to create depressions in rocks which they use as habitat.
What do molluscs feed on?
Most molluscs are herbivorous, grazing on algae or filter feeders. For those grazing, two feeding strategies are predominant. Some feed on microscopic, filamentous algae, often using their radula as a ‘rake’ to comb up filaments from the sea floor.
How do molluscs survive?
Their shell provides protection and they can hang onto rocks with their foot. Their shells are hard enough that they help protect the shore from the impact of harsh waves. These shellfish also help clean the ocean and keep it healthy.
What do phylum Mollusca eat?
Behavior. Many mollusks eat mostly algae. They use the radula to scrape algae off rocks. But larger mollusks have a greater appetite.
How is radula used in feeding?
The radula is used in feeding: muscles extrude the radula from the mouth, spread it out, and then slide it over the supporting odontophore, carrying particles or pieces of food and debris into the esophagus. … By folding the teeth inward, damage to the mouth lining is avoided and food particles are concentrated.
What gastropod means?
Definition of gastropod
: any of a large class (Gastropoda) of mollusks (such as snails and slugs) usually with a univalve shell or none and a distinct head bearing sensory organs.
How does a bivalve breathe?
Like fish, bivalve mollusks breathe through their gills. As filter feeders, bivalves gather food through their gills. Some bivalves have a pointed, retractable “foot” that protrudes from the shell and digs into the surrounding sediment, effectively enabling the creature to move or burrow.
What are the 4 groups of cephalopods?
Cephalopods are members of a class of marine animals that includes octopuses, squid, cuttlefish and nautiluses.
What do chitons look like?
Chitons are usually oval in shape. … Chitons use a large, flat foot for creeping along and clinging to rocks; they also have a well-developed radula (filelike structure) with which to scrape algae and other plant food from rocks.
How does a radula work?
It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus. The radula is unique to the molluscs, and is found in every class of mollusc except the bivalves, which instead use cilia, waving filaments that bring minute organisms to the mouth.
What is the common name of chiton?
Chiton glaucus, common name the green chiton or the blue green chiton, is a species of chiton, a marine polyplacophoran mollusk in the family Chitonidae, the typical chitons.
Is a chiton a toga?
As nouns the difference between chiton and toga
is that chiton is a loose, woolen tunic, worn by both men and women in ancient greece or chiton can be any of various rock-clinging marine molluscs of the class polyplacophora, including the genus chiton while toga is loose outer garment worn by the citizens of rome.
What is Osphradia function?
The major function of osphradium is to test the incoming water for silt and food particles. The osphradium also acts as an olfactory organ in certain mollusks and is linked with the respiratory organ. Osphradium structure resembles the feather of a bird and is also called Bipectinate.
What is visceral hump?
The visceral hump, or visceral mass, of gastropods is always contained within the shell; it generally holds the bulk of the digestive, reproductive, excretory, and respiratory systems. A significant part of the visceral hump consists of the mantle, or pallial, cavity.
What are radula teeth made from?
The teeth of the radula are formed of chitin, which is a type of polysaccharide (or biopolymer). Chitin also occurs in the mollusk shell, the crustacean and insect exoskeletons, and the beaks of cephalopods.
What is Mantle in molluscs?
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.
Which is the largest phylum of Animalia?
arthropod, (phylum Arthropoda), any member of the phylum Arthropoda, the largest phylum in the animal kingdom, which includes such familiar forms as lobsters, crabs, spiders, mites, insects, centipedes, and millipedes.
What are the 11 classification of animals?
Animal kingdom is classified into various phylums such as Phylum Porifera, Phylum Coelenterata (Cnidaria), Phylum Ctenophore, Phylum Platyhelminthes, Phylum Aschelminthes, Phylum Annelida, Phylum Arthropoda, Phylum Mollusca, Phylum Echinodermata, Phylum Hemichordata and Phylum Chordata.
What is Monopectinate Gill?
The organ of aquatic respiration is the ctenidium or gill. On the dorso-lateral wall of the branchial chamber of the mantle cavity, the ctenidium is found. … Such a gill is known as monopectinate gill.
What is squid radula?
Inside the giant squid’s sharp beak is a tongue-like organ called the radula (shown in yellow). Covered with rows of tiny teeth, it rams bite size pieces of food down the squid’s throat.
Which is the larva of Mollusca?
veliger, larva typical of certain mollusks such as marine snails and bivalves and a few freshwater bivalves. The veliger develops from the trochophore (q.v.) larva and has large, ciliated lobes (velum).
How many years do mollusks live?
Squids generally live about a year, and octopi and cuttles live from 1-4 years, depending on the species. The nautili (plural for “nautilus”), which are the only cephalopods that have an external shell, are also the longest-lived; biologists estimate that they can live up to 20 years.
Do mollusks eat fish?
What do they feed on? Molluscs are a large phylum of invertebrate animals, many of which have shells. Some mollusks consume only algae and ocean plant matter, while others may eat shellfish and even small fish.
Do mollusks lay eggs?
Mollusks reproduce sexually, and most species have separate sexes. Sexual reproduction is achieved by the formation and fusion of gametes: sperm and eggs. … During external fertilization, the female lays eggs, and they are fertilized by the male sperm outside of the female’s body.
Why do mollusks move slow?
Mollusks, the group to which slugs and snails belong, have made it 550 million years without a speeding ticket. Traveling by muscular contractions called pedal waves makes slugs and snails pretty slow. Like turtles, snails rely on a defensive shell.
Why are mollusks important?
Mollusks are among the most diverse and abundant animal groups, inhabiting many aquatic and terrestrial environments. They are important ecosystem engineers, helping to structure aquatic bottom environments and providing habitat, protection, and food to a wide array of other taxa.
What makes mollusks special?
All molluscs also have gills, a mouth and an anus. A feature unique to molluscs is a file-like rasping tool called a radula. This structure allows them to scrape algae and other food off rocks and even to drill through the shell of prey or catch fish.
Where are molluscs found?
Most mollusks are marine animals that live in habitats from shallow coastal areas to deep waters. Most stay within the sediments at the bottom of water bodies, although a few—such as cephalopods—are free swimming.
How do mollusks breathe?
Aquatic mollusks “breathe” under water with gills. Gills are thin filaments that absorb gases and exchange them between the blood and surrounding water. Mollusks have a circulatory system with one or two hearts that pump blood.
What is the common name for Mollusca?
Common Name(s): | mollusques [French] |
molusco [Portuguese] | |
molluscs [English] | |
mollusks [English] | |
Taxonomic Status: |
How does the radula move?
Both the radula and the odontophore can be moved forward (protracted) out of the mouth for feeding and brought back in (retracted) to bring in food or when finished eating. This movement is accomplished by sets of protractor and retractor muscles as seen in the diagram to the right.
How do you feed bivalves?
The posterior leaflike gills serve principally for respiration; feeding is carried out by the palp proboscides, which collect surface detritus. The vast majority of other bivalves feed on the plant detritus, bacteria, and algae that characterize the sediment surface or cloud coastal and fresh waters.
Do all molluscs have shells?
Not all mollusks have shells, however– there are plenty of species of mollusks without shells. Instead of a shell, their backs are protected by sturdy reinforced skin, scales, spines, or incomplete armored plates. The word “mollusk” comes from the Latin “molluscus,” meaning soft.