What is the body plan of mollusks?

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The body plan of a mollusk usually consists of a head region, a muscular foot, and a visceral mass of internal organs that is often contained within a dorsal shell. Each class possesses some variation on this basic plan. The organization of the gastropod body is very similar to the basic body plan of mollusks.

Also know, what are three parts of the mollusk body plan?

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.

Also Know, what type of body symmetry do Mollusca have? Molluscs are bilaterally symmetrical, although some have secondarily lost the symmetry in part; they have well-developed excretory, digestive, respiratory and circulatory systems. In all molluscs except the cephalopods, the circulatory system is open.

Herein, what are the four parts of the body plan of most mollusks?

The four parts of the mollusk body plan are the foot (used for locomotion), mantle (which secretes the shell), shell (which covers), and viceral mass (contains heart and organs). Describe the characteristics of the three major classes of mollusks.

How are mollusks important to humans?

Mollusks are important in a variety of ways; they are used as food, for decoration, in jewelry, and in scientific studies. They are even used as roadbed material and in vitamin supplements.

29 Related Question Answers Found

How are mollusks born?

HOW DO MOLLUSKS REPRODUCE? Mollusks reproduce sexually. Slugs and snails are hermaphrodites (possessing both male and female organs), but they must still mate to fertilize their eggs. Most aquatic mollusks lay eggs that hatch into small, free-swimming larvae called veliger.

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.

What are 3 types of mollusks?

An invertebrate is an animal without a backbone. The three main parts of a mollusk's body include a muscular foot, a visceral mass, and a mantle. The three main types of mollusks are gastropods, bivalves, and cephalopods. Gastropods, like slugs and snails, can live on land or in the water.

Why do Radulas not look alike?

They have chainsaw like teeth that can open barnacle shells, scrape through flesh, and tear up kelp. Why don't all radulas look alike? They have different adaptations.

What are the four characteristics of mollusks?

Some common features are :
  • Unsegmented soft body with bilateral symmetry.
  • Presence of an internal or external shell.
  • A toothed tongue (made mostly of chitin) called the radula.
  • A mantle which is a fold in the body wall that lines the shell.
  • Muscular foot (and/or tentacles in some).

Where are mollusks found?

Molluscs occur in almost every habitat found on Earth, where they are often the most conspicuous organisms. While most are found in the marine environment, extending from the intertidal to the deepest oceans, several major gastropod clades live predominantly in freshwater or terrestrial habitats.

What are the 7 classes of mollusks?

Phylum Mollusca is classified into seven classes;
  • GASTROPODA (single shelled cowries, cones etc)
  • BIVALVIA ( two shelled like clams, mussels etc)
  • APLACOPHORA (solenogasters)
  • MONOPLACOPHORA (segmented limpets)
  • POLYPLACOPHORA ( or Amphineura as it was earlier called- Chitons)
  • SCAPHOPODA (tusk shells)

What is the function of the mantle?

There are numerous functions of the mantle in mollusks, with the primary function being to enclose and protect the internal organs. The mantle leaves room in the mollusks body for the mantle cavity, which holds air or water and serves as a method for respiration.

What does the Radula do?

The radula (/ˈræd?l?, ˈr?ː-/; plural radulae or radulas) is an anatomical structure used by mollusks for feeding, sometimes compared to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the oesophagus.

How do mollusks protect themselves?

On way that mollusks protect themselves is to build a hard shell around their bodies. Clams, oysters, snails, mussels, and scallops all have shells. As long as the shell is not broken, it is hard for other animals to eat them. Another way that mollusks protect themselves is through camouflage.

How are mollusks classified?

Mollusks are subdivided into seven classes with most species found in three of those classes: Gastropoda, Bivalvia, and Cephalopoda. Gastropods make up the largest class of mollusks, and they include both snails and slugs. The remaining classes (Polyplacophora, Aplacophora, and Monoplacophora) have fewer species.

What does the term Mollusca mean?

Mollusca, meaning “soft-bodied,” is one of the largest phylums in the animal kingdom. The word mollusc (or mollusk) derives from the Latin word “mollis,” which means “soft.” There are an estimated 200,000 species of mollusk worldwide accounting for nearly a quarter of all marine life.

What are the two main parts in all mollusks?

Most mollusk have two organs that are unique to this phylum: a specialized feeding organ called a radula and a dorsal layer of tissue called a mantle. Mollusks are the first animals to have evolved organ systems for respiration and circulation.

How do mollusks move?

Most mollusks move with a muscular structure called a foot. The feet of different kinds of mollusks are adapted for different uses, like crawling, digging, or catching prey. Many mollusks have an organ called a radula (RAD you lah), which is a flexible ribbon of tiny teeth.

How do bivalves feed?

Most bivalves are filter feeders, using their gills to capture particulate food such as phytoplankton from the water. The protobranchs feed in a different way, scraping detritus from the seabed, and this may be the original mode of feeding used by all bivalves before the gills became adapted for filter feeding.

What are the 5 main classes of Mollusca?

The major classes of living mollusks include gastropods, bivalves, and cephalopods (Figure below).
  • Gastropods. Gastropods include snails and slugs. They use their foot to crawl.
  • Bivalves. Bivalves include clams, scallops, oysters, and mussels.
  • Cephalopods. Cephalopods include the octopus and squid.

Are sponges segmented?

Do sponges have segmented bodies? No. Sponges display a lower grade of body-plan organization than all other animal phyla (true metazoans). All animals that have segmented bodies (annelids, arthropods) also have internal body cavities (coelom) that are lined by mesodermal tissue.