1. Phylum Mollusca
Fig. 16.CO

2. Phylum Mollusca Large and diverse group of animals Tridacna gigas
Giant Clam
Tridacna squamosa
Fluted Giant Clam

3. Phylum Mollusca More than 500,000 known species Class Polyplacophora
Gastropoda
Class
Bivalvia
Class
Cephalopoda
chitons
Snails
Sea slugs
nudibranchs
Squid
Octopus
Cuttlefish
Nautilus
clams
More than 500,000 known species

4. Phylum Mollusca Soft Bodied Shelled Cephalization Body Divisions
Some without
Cephalization
Body Divisions
Visceral Mass- contains most of the internal organs
Muscular Foot- for movement
Mantle- houses gills
Fig. 16.1a
Tonicella lineata

5. Generalized Mollusc Anatomy
mantle
visceral mass
foot

6. Phylum Mollusca Complete digestive tract Digestive glands
Octopus briareus
Complete digestive tract
Digestive glands
Specialized feeding structures
Circulatory system
Heart (2 chambers)
Open system in most groups
Closed in cephalopods

7. Phylum Mollusca Advanced nervous system Excretory system Reproduction
Brain
Sensory organs
Eyes (simple and camera)
Sensory papillae
Excretory system
Kidney
Reproduction
Male or Female parts
Some are hermaphrodites
External & internal fertilization

8. Mating
Fig

9. Mollusc Taxonomy Polyplacophora Major classes Chitons
Chiton tuberculatus lives in the rocky intertidal zones eat algae with its radula
8 shell plates
Major classes
Polyplacophora
Chitons

10. Mollusc Taxonomy Gastropoda Major classes Subclasses: Prosobranchia
Atlantic triton’s trumpet (Charonia variegata)
Major classes
Polyplacophora
Gastropoda
Subclasses:
Prosobranchia
Sea Snails
Tiger cowrie (Cypraea tigris)

11. Mollusc Taxonomy Gastropoda Major classes Subclasses: Opisthobranchia
Spotted sea hare (Aplysia dactylomela)
Major classes
Polyplacophora
Gastropoda
Subclasses:
Prosobranchia
Opisthobranchia
Sea slugs (marine)
Phidiana hiltoni
zebra sea goddess (Hypselodoris zebra)

12. Mollusc Taxonomy Gastropoda Major classes Subclasses: Pulmonata
Helminthoglypta walkeriana
Major classes
Polyplacophora
Gastropoda
Subclasses:
Prosobranchia
Opisthobranchia
Pulmonata
Terrestrial snails/slugs
Freshwater snails
Giant banana slug (Ariolimax columbians)

13. Mollusc Taxonomy Bivalvia Major classes Polyplacophora Gastropoda
Bay scallop (Aequipecten irradians)
Major classes
Polyplacophora
Gastropoda
Bivalvia
Clams, oysters, mussels, scallops
Edible mussels (Mytilus edulis)
Ostrea edulis

14. Mollusc Taxonomy Major classes Cephalopoda Polyplacophora Gastropoda
Giant cuttlefish (Sepia latimanus)
Major classes
Polyplacophora
Gastropoda
Bivalvia
Cephalopoda
Octopus, squid, nautilus
Octopus sp
Nautilus sp

15. Mollusc Taxonomy Major classes Minor classes Polyplacophora Gastropoda
Bivalvia
Cephalopoda
Minor classes
Monoplacophora
Solenogastres
Caudofoveata

16. A Pearl Among the Swine
Fig. 16.5b

17. Gastropod Veliger Larva
Mouth
Velia
Fig. 16.7
Shell

19. Veliger
Zygote
Trochophore
Juvenile
Spat
Adult

20. Adult Abalone
Fig a

21. Class Gastropoda - Torsion
Fig

22. Gastropod Shell Coiling
Fig

23. Gastropod Gill/Mantle Cavity Evolution
Fig

24. Marine Gastropods
Cowries
Fig b

25. Marine Gastropods
Sea Hare – Aplysia sp
Fig

26. Marine Gastropods - Nudibranch
Fig

27. Squid are the largest Cephalopods

28. Nautilus Anatomy
Fig b

29. Direct Development in Cephalopods

30. Color & Morphology Changes for Camouflage