Mollusca
- Invertebrate
- Bilateral symmetry
- Protosome- during embryonic development the first opening, blastopore, forms the mouth
- Coelomates- has true coelom- a fluid filled cavity in the body that contains the digestive tract and other organs.
- Open circulatory system- blood is not contained, blood mixes with other body fluids; or Closed circulatory system- blood is completely contained, blood does not mix with body fluids
- Head-foot- functions for locomotion and contains sensory organs
- Visceral mass- contains internal organs
- Mantle- a specialized tissue that surround the visceral mass and secretes calcium carbonate to build the shell of mollusks
- Radula- acts like tongue, scrapes up food, made of chitin
- Includes three diverse classes
- Gastropods (stomach foot)- slugs and snails, open circulatory system
- Bivalves- clams,oysters, mussels, scallops, two shells hinged together, suspension feeder (no radula), open circulatory system
- Cephalopods (head foot)- squids, octopi, cuttlefish, closed circulatory system