1. What you already know (I hope)

2. Early Eukaryotes Kingdom Protista –Most diverse Kingdom Polyphyletic Should be split into multiple Kingdoms Many have sexual reproduction Autotrophs and heterotrophs

3. Acoelomates Key Features Three germ layers –Ectoderm, endoderm, mesoderm –Mesoderm forms muscle and mesenchyme Organ-system level of organization –Cephalization –Excretory system –Some have circulatory and one-way alimentary canal

4. Acoelomates Body Plan

5. Phylum Platyhelminthes Specialized Cells –Rhabdites - secrete mucous sheath –Tegument - outer covering of syncytial cells –Flame cells – Osmoregulation –Some have endolecithal egg cells – yolk contained within egg cell

6. Platyhelminthes Cross Section

7. Tegument Syncytium –Apical cell membrane missing

8. Flame Cell Osmoregulation –Beating flagella creates negative pressure to draw fluid into chamber –Water is directed through channels then through an external pore

9. Major Classes of Platyhelminthes Class Turbellaria –Planaria – free living Class Trematoda –Liver flukes – endoparasites Class Monogenea –Fish ectoparasites Class Cestoda –Tape worms – endoparasites

10. Class Trematoda Similar in structure to Turbellaria Special adaptation for endoparasitic life style –Cyst glands –Suckers and hooks for griping host Digenetic – complex life cycle with multiple hosts

11. Liver Fluke

12. Liver Damage Caused By Flukes Scar tissue Blocked bile ducts

13. Flukes in Liver Section

14. Fasciolopsis - Anterior End

15. Schistosoma mansoni Blood fluke Male and female are dioecious

16. Schistosoma cercaria

17. Class Cestoda Tapeworms - endoparasites Key Features –Lack a digestive system –Composed of reproductive units called proglottids –Adult tegument covered in microvilli-like projections – increases surface area, non- ciliated

18. Tapeworm New proglottids are added just behind the scolex

19. Tapeworm Tegument Microvilli help with food adsorption Sensory cells – no other sense organs

20. Mature Proglottid Reproductive unit Mature proglottids are either shed or produce shelled embryos Each proglottid has both male and female organs

21. Tape Worm Life Cycle

22. Taenia solium Pork tapeworm

23. Taenia Cyst in Muscle

24. Phylum Nematoda Found everywhere Use pseudocoel as a hydrostatic skeleton –Collagen cuticle –Longitudinal muscles Free living and parasites Dioecious

25. Nematode Body Plan

26. Muscle Structure Longitudinal muscles –Parallel to ventral and dorsal nerve cords –Muscle cells form processes to associate with nerve cells –Muscles act against the hydrostatic skeleton

27. Muscle/Nerve Structure

28. Digestion and Metabolism Pharynx –Radial muscles Intestine –Single cell layer with no muscles –Body movement and ingestion moves food Parasitic nematodes often lack complete aerobic respiration

29. Arthropods Adapted to aquatic and terrestrial environments Probably first animals on land and in air Most diverse animal phylum

30. Segmentation Pair of appendages per segment –Reduced number for most arthropods –Specialized – locomotion, feeding, defense… Fused segments – tagmata –Head, thorax, abdomen

31. Exoskeleton Composition –Chitin – cross-linked polysaccharides –Protein and lipids –Calcium salts – very hard Advantages –Protection –Muscle attachment –Joints –Wings

32. Ecdysis

33. Respiration Terrestrial – trachea (network of breathing tubes) Aquatic – gills High oxygenation = high metabolic rate

34. Sense Organs Compound eye –Ommatidia Photoreceptors Lens Pigment cells Nerve fiber Antennae –Tactile, chemosensitive

35. Compound Eye

36. Subphylum Chelicerata No mandibles – mostly suck food Two tagmata –Cephalothorax –Abdomen Six pairs of appendages –1 pair chelicera –1 pair pedipalp –4 pair walking legs

37. Class Arachnida Spiders, mites, scorpions, ticks Terrestrial and marine Chelicera often develop into fangs or pincers Most feed by sucking fluid from prey or host Specialized organs –Excretory system - Malpighian tubles Allows conservation of water –Book lungs or book gills

38. Uniramia Key Features –Legs do not branch –Specialized feeding mandibles –Tracheal system of gas exchange –Malpighian tubules –Single pair of antennae

39. Insecta Over one million species Found all over the world –Not found in marine environment – dominated by crustaceans Structural Features –Tagmata – head, thorax, abdomen –Legs only from thorax –Wings

40. Insect Flight Muscles

41. Figure-8 Pattern Upstroke –Leading edge faces up Downstroke –Leading edge faces down

42. Flight Muscle Control Synchronous –One impulse = one stroke –Dragonflies, butterflies Asynchronous –One impulse = multiple strokes –Flies, bees, midges

43. Basic Anatomy

44. Digestive System Foregut –Mouth, esophagus, crop, gizzard –Grinding and storage Midgut –Stomach and gastric ceca (increases surface area) –Digestion and most absorption Hindgut –Intestine, rectum, anus

45. Excretion Malpighian Tubules –Extensions off of the intestine –Project into the haemocoel –Exchanges waste with haemolymph

46. Metamorphosis Holometabolous –Complete – example: butterfly –Egg  Larva  Pupa  Adult –Many larval tissues disintegrate during pupa stage

47. Metamorphosis Hemimetabolous –Partial – example: roach –Egg  Nymphs  Adult –Nymphs are similar to adults