What is a mollusc and its taxonomy

1
What is a mollusc and its taxonomy
A soft bodied invertebrate with a calcium
carbonate shell
Kingdom- Animalia Phylum- Mollusca Class Caudofov
eata Aplacophora Polyplacophora-
chitons Monoplacophora Bivalvia- clams,
mussels, scallops, oysters Scaphopoda- tusk
shells Gastropoda- snails, slugs, abalone,
limpets, cowries, conch Cephalopoda- octopuses,
squids, nautilis Rostroconchia-
extinct Helcionelloida- extinct Bellerophontidae
- extinct
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General anatomy of five molluscan classes
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Where do different molluscs live ?

• Polyplacophora-. rocky shores, intertidal, stuck
  to rocks
• Monoplacophora- deep water
• Bivalvia- benthic, some burrow
• Scaphopoda- burrow in deep sea water sediments
• Gastropoda- benthic and live on all types of
  surfaces
• Cephalopoda- pelagic

4
What do each group of mollusc eat?

• Polyplacophora- feed on small particles of algae
  on the rock surface which are scraped off using
  the radula
• Monoplacophora- graze on microorganisms and
  algae
• Bivalvia- filter feeders
• Scaphopoda- feed on detritis and small organisms
• Gastropoda- herbivorous and scrape algae
• Cephalopoda- predators

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Basic molluscan body plan

• Mantle tissue that secretes the calcium carbonate
  shell
• A body divided into three regions, the head,
  foot, and visceral mass
• Radula, structure made of chitin used for feeding
  
• Foot used to move, to dig etc..

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How do molluscs move around and How are they
able secure themselves?

• Have a muscular foot for movement which is
  modified into tentacles for squid octopus
• Byssal threads- protein strands used to anchor
  mussels to something

7
How do molluscs mate and grow to maturity?

• Separate sexes and sexual reproduction
• Some lay eggs and some bear live young
• Some with internal and external reproduction

8
How do molluscs relate with their environment

• Primary and secondary consumers

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How are mollusks harmful
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Human and Mollusc Interaction

• Source of food
• Shells are a source of calcium for some birds
• Crushed shells are used to kill agricultural
  pests. Mollusks also nourish humans culturally.
• Mollusk shells served as money in some early
  cultures
• Monitoring water pollution.