1. Zoology Phylum Mollusk

2. I. Intro to Mollusks A. Mollusk  soft bodied B. 2 nd largest phyla 1. small  large 2. fast movers  slow movers 3. intelligent  non-intelligent 4. Deep seas  mountain tops C. Ex: squid, clam, oyster, octopus, snail, slugs, etc. D. Used as a food source 1. clams, oysters, etc. E. Used for jewelry (pearls) F. All have a “foot”  specialized muscular organ

4. II. Cephalopods A. Facts 1. Cephalo = head / poda = foot 2. Includes…squid, octopus, nautilus 3. Active predators 4. shell  nautilus 5. no shell  octopus + squid

5. B. The Nautilus

6. 1. Locomotion -”foot” acts as a siphon  pushes water out -gas filled chambers 2. Nervous System -intelligent -chemoreceptor cell  used to camouflage 3. Others -60 to 90 tentacles (no suckers) -sexual reproduction -radula  tongue like structure i. 250,000 teeth ii. Conveyor belt

8. C. The Squid

9. 1. Locomotion -same as nautilus 2. Nervous System -exceptional eyes -chemoreceptor cell 3. Others -sepia  ink sac; helps hide from enemies -8 arms / 2 tentacles -pen  acts as backbone of squid -beak – used to break up food

11. D. The Octopus

12. 1. Locomotion – same as squid 2. Nervous System -great eye sight -extremely intelligent (can be conditioned) -chemoreceptor cells 3. Others -sepia -pen -8 arms – all with suction cups -beak – used to break up food

14. III. Gastropods A. Facts 1. gaster = stomach / poda = foot 2. Largest group of mollusks (50,000) 3. Ex: snails and slugs 4. Dioecious (individual sexes) or monoecious (both sexes) 5. can be terrestrial (gills or lungs) 6. Sluggish or slow moving 7. Usually feed on algae or plankton 8. Occupy a shell for protection

15. B. Conus 1. active predator 2. uses worm-like tongue to lure in prey -fish bites…proboscis fires…injects venom…paralyzes fish 3. lethal sting to humans

16. IV. Class Pelecypoda (Bivalves) A. Facts 1. pelecy = hatchet / poda = foot 2. Ex: mussels, clams, scallops, oysters 3. Filter Feeders 4. no radula 5. Dioecious

17. B. The Clam 1. External Anatomy a. Umbo – oldest part of the shell b. Hinge Ligament – keeps the 2 shells connected c. Growth Rings

18. Growth Rings 1. 2. Umbo Anterior Side Ventral Side 3. Hinge Ligament

19. 2. Internal Anatomy a. Siphons -incurrent  takes water + food into clam -excurrent  removes waste b. Mantle – tissue that covers the organs of the clam -similar to skin c. Palp – guide food into the mouth d. Heart -3 chambered -beats slow (0.2 – 30 times/min.)

20. e. Kidneys -filter blood -U shaped -Nephridial Tubules – connect to the kidney f. Ganglia -3 pairs -poorly developed g. Muscles -anterior adductor -posterior adductor -both close the shell -Extremely strong