1. Fig. 33-1

2. Fig. 33-2 ANCESTRAL PROTIST Common ancestor of all animals Calcarea and Silicea Eumetazoa Bilateria Cnidaria Lophotrochozoa Ecdysozoa Deuterostomia

3. Fig. 33-3-1 Calcarea and Silicea (5,500 species) A sponge Cnidaria (10,000 species) A jelly Acoela (400 species) Acoel flatworms (LM) 1.5 mm LOPHOTROCHOZOANS Platyhelminthes (20,000 species) A marine flatworm Ectoprocta (4,500 species) EctoproctsA brachiopod Brachiopoda (335 species) Rotifera (1,800 species) A rotifer (LM) A ctenophore, or comb jelly Ctenophora (100 species) A placozoan (LM) 0.5 mm Placozoa (1 species)

4. Fig. 33-3-2 An acanthocephalan (LM) Acanthocephala (1,100 species) Nemertea (900 species) A ribbon worm ECDYSOZOA Loricifera (10 species)Priapula (16 species) A loriciferan (LM) A priapulan 50 µm Cycliophora (1 species) Mollusca (93,000 species) A cycliophoran (colorized SEM) 100 µm An octopus Annelida (16,500 species) A marine annelid

5. Fig. 33-3-3 Tardigrada (800 species) Nematoda (25,000 species) Onychophora (110 species) Arthropoda (1,000,000 species) DEUTEROSTOMIA Hemichordata (85 species) Echinodermata (7,000 species) Chordata (52,000 species) Tardigrades (colorized SEM) 100 µm A roundworm An acorn worm A sea urchin An onychophoran A scorpion (an arachnid) A tunicate

6. Fig. 33-4 Azure vase sponge (Callyspongia plicifera) Spongocoel Osculum Pore Epidermis Water flow Mesohyl Choanocyte Flagellum Collar Food particles in mucus Choanocyte Amoebocyte Phagocytosis of food particles Spicules Amoebocytes

7. Fig. 33-5 Polyp Mouth/anus Body stalk Tentacle Gastrovascular cavity Gastrodermis Mesoglea Epidermis Tentacle Mouth/anus Medusa

8. Fig. 33-6 Tentacle Nematocyst “Trigger” Cuticle of prey Thread discharges Thread (coiled) Cnidocyte Thread

9. Fig. 33-7 (a) Colonial polyps (class Hydrozoa) (b) Jellies (class Scyphozoa) Sea wasp (class Cubozoa) (d) Sea anemone (class Anthozoa) (c)

10. Table 33-1

11. Fig. 33-9

12. Fig. 33-10 Pharynx Gastrovascular cavity Mouth Eyespots Ganglia Ventral nerve cords

13. Table 33-2

14. Fig. 33-11 Human host Motile larva Snail host Ciliated larva Male Female 1 mm

15. Fig. 33-12 Proglottids with reproductive structures Hooks Sucker Scolex 200 µm

16. Fig. 33-22 Epidermis Circular muscle Longitudinal muscle Dorsal vessel Chaetae Intestine Nephrostome Fused nerve cords Ventral vessel Metanephridium Septum (partition between segments) Coelom Cuticle Anus Metanephridium Crop Intestine Gizzard Ventral nerve cord with segmental ganglia Blood vessels Subpharyngeal ganglion Mouth Cerebral ganglia Pharynx Esophagus Clitellum Giant Australian earthworm

17. Fig. 33-23 Parapodia

18. Fig. 33-24

19. Fig. 33-15 Nephridium Visceral mass Coelom Mantle cavity Heart Intestine Gonads Stomach Shell Radula Mouth Esophagus Nerve cords Foot Gill Anus Mouth Radula

20. Table 33-3

21. Fig. 33-16

22. Fig. 33-17 (a) A land snail (b) A sea slug

23. Fig. 33-18 Mouth Anus Mantle cavity Stomach Intestine

24. Fig. 33-19

25. Fig. 33-20 Mouth Digestive gland Mantle Hinge area Gut Coelom HeartAdductor muscle Anus Excurrent siphon Water flow Incurrent siphon Gill Gonad Mantle cavity Foot Palp Shell

26. Fig. 33-21 Octopus Squid Chambered nautilus

27. Fig. 33-29 Cephalothorax Antennae (sensory reception) Head Thorax Abdomen Swimming appendages (one pair located under each abdominal segment) Walking legs Mouthparts (feeding) Pincer (defense)

28. Table 33-5

29. Fig. 33-27

30. Fig. 33-30

31. Fig. 33-31 Scorpion Dust mite Web-building spider 50 µm

32. Fig. 33-35 AbdomenThoraxHead Compound eye Antennae Heart Dorsal artery Crop Cerebral ganglion Mouthparts Nerve cords Tracheal tubes Ovary Malpighian tubules Vagina Anus

33. Fig. 33-37

34. Fig. 33-38 (a) Ghost crab (b) Krill(c) Barnacles

35. Fig. 33-39 Anus Stomach Spine Gills Madreporite Radial nerve Gonads Ampulla Podium Tube feet Radial canal Ring canal Central disk Digestive glands

36. Fig. 33-40 (a) A sea star (class Asteroidea) (c) A sea urchin (class Echinoidea) (e) A sea cucumber (class Holothuroidea) (b) A brittle star (class Ophiuroidea) (d) A feather star (class Crinoidea) (f) A sea daisy (class Concentricycloidea)