How is the mollusk mantle related to its shell?

1 Answer

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Mantle or Palladium only secretes shell. It's an adaptation for protection .
Shell here works as exoskeleton & is calcareous by nature.
Calcareous suggests partly or completely composed of calcium carbonate .
All Mollusks have this exoskeleton.

Exceptions:

  • Most of the members of Cephalopods do not have shells (as they respire through general body surface)
  • The shell of the Sepia (Cuttle fish) is not well-formed