Polyplacophora Gastropoda Bivalvia Scaphopoda Cephalopoda Phylum Mollusca Polyplacophora Gastropoda Bivalvia Scaphopoda Cephalopoda Phylum Mollusca

Molluscs Have adapted to a wide variety of habitats Terrestrial, marine, benthic, and accomplished swimmers. Phylum Mollusca

The Molluscan Body Plan The body plan is similar and distinct from all other phyla The Mollusca body plan includes: A large muscular foot A radula Mantle and mantle cavity Usually a small head Soft unsegmented body A hard non-living calcareous shell Phylum Mollusca

The Foot Phylum Mollusca

The Radula Radula Some molluscs have a rod of digestive enzymes (crystalline style) in the stomach Phylum Mollusca

The Mantle The mantle is the body wall that enclose the body cavity Phylum Mollusca

The Mantle Cavity Houses the viscera and comb-like molluscan gills Ctenidia are respiratory in function and can collect food particles Mantle cavity also is the site for reproductive, excretory, and digestive systems Phylum Mollusca

Taxonomic Summary Phylum Mollusca Class Polyplacophora Class Gastropoda Subclass Prosobranchia Subclass Opisthobranchia Class Bivalvia Class Scaphopoda Class Cephalopoda Phylum Mollusca

Class Polyplacophora Defining characteristics Chitons Shell forms as a series of 7 to 8 separate plates Chitons Phylum Mollusca

Chiton Lifestyles Found close to shore mainly in the intertidal where they live on hard substrates Phylum Mollusca

Chiton Anatomy Phylum Mollusca

Ingestion and Digestion Radula is used to scrape algae from the rocks Mouth is anterior and anus is posterior; linear digestive tract Phylum Mollusca

Reproduction Reproduction Sexes are separate with fertilization occurring in the water column Trochophore larvae Free swimming which settles and metamorphoses into an adult Phylum Mollusca

Local Representative Eastern Beaded Chiton (Chaetopleura apiculata) Occurs subtidally on old shells Phylum Mollusca