What is a sentence for mollusk?
1 Many mollusks have tentacles. 2 Limpets, snails and octopuses are mollusks. 3 There are two types of mollusk that are actively venomous. 4 Mollusks, like all living organisms, constantly adapt to changes in environmental conditions.
What class of mollusks is most diverse?
Fertilization is ectaquatic, the trochophore-like larvae are lecithotrophic. Gastropoda (limpets, snails, whelks, slugs) is by far the most diverse group of molluscs with about 100,000 species (0.5 mm to 100 cm long) that inhabit all marine, freshwater and terrestrial habitats.
What are the four most common and diverse classes of molluscs?
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.
What is the meaning of Mollusca?
: any of a large phylum (Mollusca) of invertebrate animals (such as snails, clams, or squids) with a soft unsegmented body usually enclosed in a calcareous shell broadly : shellfish.
How will you describe mollusk?
mollusk, also spelled mollusc, any soft-bodied invertebrate of the phylum Mollusca, usually wholly or partly enclosed in a calcium carbonate shell secreted by a soft mantle covering the body.
Which of the following represent classes of mollusks?
he phylum Mollusca is divided into five main classes: pelecypods, or bivalves (Pelecypoda, or Bivalvia), includes oysters, clams, mussels; gastropods (Gastropoda), snails, sea slugs; cephalopods (Cephalopoda), squids, octopuses; scaphopods (Scaphopoda), tooth shells; Polyplacophora, chitons.
Why are molluscs so successful?
If success is measured in terms of number of species and variety of habitats to which they have become adapted, then molluscs are one of the three most successful groups in the animal kingdom. Molluscs have evolved a distinctive and highly successful body plan that features a mantle, shell, muscular foot, and radula.
How do you classify Mollusca?
Mollusks can be segregated into seven classes: Aplacophora, Monoplacophora, Polyplacophora, Bivalvia, Gastropoda, Cephalopoda, and Scaphopoda. These classes are distinguished by, among other criteria, the presence and types of shells they possess.
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.
How do you spell Mollusca?
the phylum comprising the mollusks.
What are the special features of the phylum Mollusca?
The visceral mass, in its compact form, contains the vital organs of the body, taking the form of dorsal humps or dome. These are the special features of Mollusca. Phylum Mollusca is a very diverse group of mainly marine species (85,000 species), with a dramatic range of forms.
How many species of molluscs are there in the world?
Cornu aspersum (formerly Helix aspersa) – a common land snail. Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda. The members are known as molluscs or mollusks ( / ˈmɒləsk / ). Around 85,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000
What do we know about the taxa of the molluscs?
Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat.
How many pairs of gills do molluscs have?
Most molluscs have only one pair of gills, or even only a singular gill. Generally, the gills are rather like feathers in shape, although some species have gills with filaments on only one side. They divide the mantle cavity so water enters near the bottom and exits near the top.