1. Kingdom: Animalia Phylum: Mollusca
Body Plan: Two Main Regions
*Head *Foot
mouth Large muscle used
sensory organs for 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. Killer Cone Snail

6. 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

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

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

9. Clam vs. The World

10. Phylum: Mollusca Class: Cephalopoda
Head Foot
Octopuses,
squids,
cuttlefish,
and chambered nautilus
Free swimming Predators
Circle of tentacles with powerful suction cups
Beak
Brain - Largest of all Invertebrates
Closed Circulatory System
Chromatophores – pigment cells

11. Class: Cephalopoda 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

12. Octopus vs. Shark

13. 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 2nd largest invertebrate
Ink Sac
Siphon
Male/Female
Pen (internal skeleton - remnant of shell)
Beak

14. Colossal Squid
Worlds Largest Squid Species: 46 feet

15. Sudden Death Cuttlefish

16. Phylum: Annelida Earthworms, leeches, etc. Segmented Worms
Kingdom: Animalia
Phylum: Annelida
Earthworms, leeches, etc.
Segmented Worms

17. Characteristics 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

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

19. Earthworm: Lumbricus terrestris
Nocturnal
More than 100 segments
Circular and longitudinal muscles
Setae grip the ground

20. Feeding & Digestion
Pharynx esophagus  crop  gizzard  long intestine  anus
Pharynx – muscle in front that sucks in food
Crop – temporarily stores food
Gizzard – grinds soil up to remove nutrients
Maintain fertility of soil
Aerate soil and loosen soil

21. 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

22. 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)

23. 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

24. Class: Hirudinea (leeches)
No setae; no parapodia
Live in calm bodies of fresh water or moist vegetation
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