1. Coelomates Protostomes
Mouth develops from the blastopore
Cleavage is spiral and determinate
ALL HAVE A TRUE COELOM!

2. Mollusca Bilateral symmetry Open circulatory system
Soft bodied, with hard shell protection
Reduced or no segmentation
Radula; rasping tongue to sxrape food
True coelom
Many internal organs
Three body parts
Foot
Visceral mass
Mantle

4. Four Classes Polyplacophora Gastropods Chitons Cling to rocks
Live on rocky shores
Use muscular foot to grip
Gastropods
Snails, slugs, nudibranchs
Largest class
Shell protects body
Torsion leads to twisted body
Uses radula to scrape algae and graze on plants

5. Bivalves: Cephalopods Clams, oysters, mussels, scallops
Possess shell divided and hinged into two halves
Filter feeders
Sedentary lifestyle
Cephalopods
Squid and octopus and nautilus
Use jaws to bite prey
Mouth as base of foot (foot drawn into several tentacles)
Complex brains and capable of learning and moving fast
Mantle reduced or absent
Can get large, How?

6. Annelids SEGMENTATION! Closed circulatory system Alimentary canal
Five pairs of hearts
Gas exchange across skin
Metanephridia for gas exchange
Nitrogenous wastes exit from each segment through pores
Nervous system with ganglia and ventral nerve cords

7. Three classes: Oligocheates Polycheates: Hirudinea: Earthworms
Fanworms
Tube dwellers (marine)
Hirudinea:
Leaches
Used to treat bruised tissues and to stimulate circulation

8. Evolutionary trends in Annelids
Coelom
serves as hydrostatic skeleton
Developed complex organ system
Protects internal structures
Segmentation
Specialization of body segments

9. Arthropods Key characteristics: Jointed appendages Segmentation
Hard exoskeletons
Extensive cephalization
Open circulatory system
Gas exchange gills in water, book lungs or spiracles on land

10. Success vs. Limitations
Successes:
Exoskeleton, lets the thrive on land, but limited
Jointed appendages allowed for walking and then flying in some
More successful organization of segments
Limits:
Exoskeleton is shed
Limited brain size
Limited body size

11. Subphyla Trilobites Chelicerates Uniramia Extinct group
Show pronounced segmentation, with little variation in appendages
Early, primitive arthropods
Chelicerates
Includes the arachnids
1-2 body segments with 8 legs
Uniramia
Includes insects, milipedes and centipedes

12. Classes Arachnids Insects Crustaceans Scorpions, spiders, mites
1pair of antennae
6 legs
3 body segments
Crustaceans
Crabs, crayfish, lobsters, isopods (pill bugs)
2 or 3 body segments

13. Deuterostomes Radial indeterminate cleavage
Blastopore becomes the anus

14. Echinoderms Secondarily evolved radial symmetry
Unique water vascular system
Has mouth and anus
Has endoskeleton

15. Classes Aseroidea Ophiuroidea Echinoidea Holothuroidea Sea stars
Brittle stars
Echinoidea
Sea urchins and sand dollars
Holothuroidea
Sea cucumbers

16. To what phylum does this organism belong?
Phylum Annelida

17. To what phylum does this organism belong?
Phylum Cnidaria

18. To what phylum does this organism belong?
Phylum Mollusca

19. To what phylum does this organism belong?
Phylum Echinodermata

20. To what phylum does this organism belong?
Phylum Arthropoda

21. To what phylum does this organism belong?
Phylum Nematoda

22. To what phylum does this organism belong?
Phylum Platyhelminthes

23. To what phylum does this organism belong?
Phylum Porifera

24. What evolutionary innovation both led to and limited the success of the phylum to which this organism belongs?
. . . the exoskeleton

25. What type of symmetry does this organism exhibit?
. . . none

26. What evolutionary innovation does the phylum to which this organism belongs have over Nematoda?
. . . segmentation

27. . . . it is one way; having both a mouth and an anus
What is unique about the digestive system of this organism, and others that belong to the same phylum?
. . . it is one way; having both a mouth and an anus

28. . . . bilateral symmetry and celphalization
What two evolutionary innovations are common to the phylum to which this organism belongs?
. . . bilateral symmetry and celphalization

29. What type of symmetry does this organism, and others belonging to the same phylum, exhibit?
. . . radial symmetry

30. What evolutionary innovation is first exhibited by the phylum to which this organism (a giant squid) belongs?
. . . the coelom

35. Moth mimic and model

47. An open circulatory system limits the size of these animals

48. The closed circulatory system is much more efficient!