1. Class Bivalvia 1 Phylum Mollusca Class Bivalvia

2. 2 Defining characteristics – Two-valved shell – Body flattened laterally This class contains clams, oysters, mussels, scallops, and shipworms

3. Class Bivalvia 3 Bivalves and You Many species are edible Also, an important food item for our commercially important fish Important to humans in their ability to strain harmful bacteria out of polluted waters

4. Class Bivalvia 4 Bivalve Locomotion? Most bivalves move by expansions and contractions of the foot Mussels usually are sessile and attach to substrate with threads

5. Class Bivalvia 5 Bivalve shells

6. Class Bivalvia 6 The Mantle

7. Class Bivalvia 7 Bivalve Feeding Bivalves are filter feeders – Ctenidia are used for feeding & respiration and are enlarged and folded to increase surface area

8. Class Bivalvia 8 Ctenidia Structure

9. Class Bivalvia 9 Ingestion & Digestion In the stomach food is wound on the crystalline style

10. Class Bivalvia 10 Bivalve Reproduction Dioecious The male sheds sperm into the water column – Sperm can enter the female or fertilization can occur in the water column Larvae develop from a trochophore larvae to a veliger

11. Class Bivalvia 11 Local Representatives Northern Quahog (Mercenaria mercenaria) Common Sand Clam (Tagelus plebeius) Eastern Oyster (Crassostrea virginica)