Phylum Mollusca Fig. 16.CO

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

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

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

Generalized Mollusc Anatomy mantle visceral mass foot

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

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

Mating Fig. 16.40

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

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)

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)

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)

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

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

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

A Pearl Among the Swine Fig. 16.5b

Gastropod Veliger Larva Mouth Velia Fig. 16.7 Shell

Veliger Zygote Trochophore Juvenile Spat Adult

Adult Abalone Fig. 16.15a

Class Gastropoda - Torsion Fig. 16.13

Gastropod Shell Coiling Fig. 16.14

Gastropod Gill/Mantle Cavity Evolution Fig. 16.17

Marine Gastropods Cowries Fig. 16.20b

Marine Gastropods Sea Hare – Aplysia sp Fig. 16.21

Marine Gastropods - Nudibranch Fig. 16.22

Squid are the largest Cephalopods

Nautilus Anatomy Fig. 16.36b

Direct Development in Cephalopods

Color & Morphology Changes for Camouflage