1. Kingdom: Animalia Phylum Mollusca Body Plan: Two Main Regions *Head*Foot mouthLarge muscle used sensory organsfor locomotion *Visceral mass contains heart, organs of digestion, excretion, and reproduction *Mantle - layer of epidermis covering the visceral mass

2. Phylum: Mollusca Class: Gastropoda Stomach Foot Conch, snails, abalones (single shell) Slugs and nudibranchs (no shell) Open Circulatory System – no blood vessels –Organs are bathed in blood Torsion: during larval development the visceral mass twists around 180 degrees *allows animal to withdraw inside shell as an adult

4. mantle secretes calcium carbonate shell Protects gills Ganglia - paired clusters of nerve cells Radula - flexible, tongue-like strip of tissue covered with tough, abrasive teeth

5. Phylum: Mollusca Class: Pelecypoda Hatchet Foot Clams, oysters, and scallops Bivalves (two shells) Adductor muscles that open and close the shell Open Circulatory Filter feeders

6. Shell (consists of three layers) 1.Outer layer protects against acidity of water 2.Middle layer of calcium carbonate strengthens the shell 3.Inner prismatic layer protects the animals soft body *Pearl - grain of sand between the mantle it gets coated with the inner layer

7. Clam Cilia on gills create water current –incurrent siphon –excurrent siphon Hinge Umbo Muscle Scars Mantle Scar Foot Visceral Mass - organs Gills Digestive Gland - green Pedipalps-reproductive organ

8. Phylum: Mollusca Class: Cephalopoda Free swimming, predatory existence Circle of tentacles with powerful suction cups Beak Brain-largest of all invertebrates Closed Circulatory System Chromatophores-pigment cells Head Foot Octopuses, squids,cuttlefish, and chambered nautilus

9. Class: Cephalopoda (Squid) Ten tentacles - longest two used for capturing prey Muscular mantle propels squid with jet propulsion The giant squid: Architeuthis may reach 43 feet Worlds 2 nd largest invertebrate Ink Sac Siphon Male/Female Pen (internal skeleton-remnant of shell) Beak

10. Class: Cephalopoda Octopus and Chambered Nautilus Octopus eight tentacles jet propulsion more likely to crawl along bottom no shell Chambered Nautilus only cephalopod with external shell shell with gas-filled chambers for buoyancy

11. Kingdom: Animalia Phylum: Annelida Earthworms, leeches, etc.

12. Characteristics and Classification Bilaterally symmetrical Segmented worms – allows for efficient movement (shortening & lengthening of the body) Setae – external bristles Parapodia – fleshy protrusions # of setae and presence or absence of parapodia divide the phylum into 3 classes

13. Class Oligochaeta “few bristles” Live in soil or in fresh water No parapodia Few setae on each segment Ex: earthworm

14. Earthworm: Lumbricus terrestris Nocturnal Structure and Movement More than 100 segments Circular and longitudinal muscles Setae grip the ground Feeding & Digestion Pharynx  esophagus  crop  gizzard  long intestine  anus Crop – temporarily stores food Gizzard – grinds soil up to remove nutrients Maintain fertility of soil Aerate soil and loosen soil

15. Closed circulatory system Ventral & Dorsal blood vessel Aortic arches – five pairs of muscular tubes Respiration Oxygen and carbon dioxide diffuse directly through the skin (moist) Excretion Nephridia – excretory tubules in each segment except first 3 and the last one

16. Chain of ganglia connected by a ventral nerve cord Several ganglia are fused in the anterior segments to form the cerebral ganglia (brain) process simple senses – light, touch, chemicals, moisture, T, and vibrations Reproduction Hermaphrodites (can’t fertilize own eggs) Clitellum – thickened region secretes mucus Sperm is secreted into the mucus and travels to the Seminal receptacles (stored)

17. Class Polychaeta “many bristles” Numerous setae & parapodia Parapodia function in gas exchange Antennae and specialized mouthparts Most live in marine habitats Some are free-swimming predators Others feed on sediment as they burrow for food

18. Class: Hirudinea (leeches) Live in calm bodies of fresh water or moist vegetation No setae; no parapodia Sucker at each end of their bodies used to attach to surfaces Some are parasitic – can secrete an anesthetic and an anticoagulant so they can feed on blood Can ingest 10X their own body weight