Phylum MolluscaPhylum Mollusca

There are 5 classes:There are 5 classes:

Class Amphineura – Chitons, 8 shellsClass Gastropoda – ‘Stomach foot’Class Bivalvia – 2 valves/shellsClass Scaphopoda – ‘tooth-shaped’ shellsClass Cephalopoda – ‘head attached to foot’

All members of the Phylum All members of the Phylum Mollusca have:Mollusca have:

Muscular footMantleShell

Visceral Mass

Class AmphineuraClass AmphineuraChitonsChitons

Have 8 shells This diagram – dorsal

surface

Ventral muscular surfaceVentral muscular surface

Muscular portion: foot

Class GastropodaClass Gastropoda

‘Stomach-foot” Movement done on

‘muscular foot’

Class Gastropoda - SnailsClass Gastropoda - Snails

Snail DiagramSnail Diagram

Gastropods - Sea Gastropods - Sea slugs/nudibranchsslugs/nudibranchs

Class BivalviaClass Bivalvia

2 shells Clams Oysters Mussels

Typical Shell/ValveTypical Shell/Valve

Class ScaphopodaClass Scaphopoda

Tooth or tusk shaped shells

Scaphopoda DiagramScaphopoda Diagram

Class CephalopodaClass Cephalopoda

Cephalopods have a ‘head’Cephalopods have a ‘head’

Cephalopods include:Cephalopods include:

Octopi Squid Cuttlefish Nautiluses

Have internal shells Swim with jet

propulsion