1. Phylum Mollusca

2. Attributes of the molluscs Segmental Trochophore larvae Head, foot and body component Shell is secreted by mantle –Periostracum –Prismatic –Mother of pearl==nacreous Radula in the mouth cavity Have pairs of feather like gills--ctenidial gills Paired excretory organs

3. Classes Monoplacophora Polyplacophora Gastropoda Bivalvia Cepahalopoda Scaphopoda

4. Monoplacophora Neopilina-- Missing links= Architype==theoretical construct Homeobox genes

5. Polyplacophora Chitons Chitin--a complex mucopolysaacharide Pieces of eight=shell is in eight pieces Foot looks segmental Paired gills in the mantle cavity

6. Gastropoda All mollusk characteristics Shell –Simple –Coiled shell –Lacking Torsion –Veliger –Walter GarstangWalter Garstang

7. Cephalopoda Head is surround by the foot in the form of arm/tentacles Radula is present but vestigial, chitin jaws Muscular mantle and siphon allows for jet propulsion Paired ctenidial gills Have a partially closed circulatory system with visceral and gill hearts Very efficient digestive system

8. Kinds of cephalopodscephalopods Nautiloids Chamber Nautilus –The Chambered Nautilus PoemThe Chambered Nautilus Poem Squid (calamari) shell reduced replaced by chitinous pen Cuttlefish octopus

9. Bivalvia (Pelcypoda) Shell of two halves Mantle is often produced into a siphon –Incurrent/excurrent Gill is sheet-like (lamellibranch) Foot may be extensible or small or lacking –Gooeyduck, mussel, scallop Most are filter feeders –Osphraedia in incurrent siphon detect the nature of the incoming stream

10. Scaphopoda Shell elongate, hollow tube Foot works similar to that of bivalves only circular in nature, with tentacle-like structures around Lacks gills Mantle cavity tubular Wampum