Phylum Mollusca

Phylum Mollusca

1. Anatomy

   • Mantle: Thin layer of tissue that covers body like a cloak
   • Shell: Made by glands in the mantle that secretes calcium carbonate
   • Visceral mass: Beneath the mantle and consists of internal organs
   • Muscular foot: Used for crawling, spade-shaped for burrowing and tentacles for capturing food

2. Reproduction

   • Mollusks are primarily of separate sexes
   • Some are hermaphrodites
   • Eggs and sperm are released into the water and fertilization occurs there by some species
   • Many mollusks develop into free-swimming larvae

3. Cephalopoda

   • Can change color due to chromatophores, pigment cells within its skin
   • Soft-bodied with head attached to the foot which is divided in tentacles
   • Swim by using jet propulsion method
   • Squids and Octopuses have beaks that are similar to a birds beak
   • Shown having observational skills

4. Bivalvia

   • Clams, oysters, mussels and scallops
   • Have 2 shells that are held together by powerful muscles
   • The only Mollusks that do not have a radula
   • Feed by siphoning and filtering large particles of water
   • Starfish and sea birds feed on them

5. Gastropoda

   • Snails, slugs and sea hares
   • "Stomach Foot"
   • Slugs and Sea hares lack a shell
   • Can be found in gardens, woodlands, deserts, rivers, lakes and oceans
   • Coiled shell and have a operculum that is a trap door to close the body in the shell

6. By Madelene Eaton-Nelson