1. Parazoa no true tissues
Radiata
Bilateria
Eumetazoa
Parazoa no true tissues
Multicellularity

2. Quiz (Champaca) What is the literal meaning of Platyhelminthes?
A muscular tube used to suck food into the gastrovascular cavity.
Platyhelminthes depend on what process to respire?
What is the term used to describe the three germ layers?
True or False: Platyhelminthes can be parasitic.

3. Phylum Platyhelminthes Flatworms
with tissues  organ systems
triploblastic
bilaterally-symmetric
with cephalization
acoelomates
Pseudocerus sapphirinus
Pseudobiceros bedfordi
Phrikoceros sp.
Acanthozoon sp.
Marine flatworms of the Philippines from

4. Phylum Platyhelminthes Feeding in free-living flatworms
carnivores or detritivores
incomplete digestive system
highly-branched GVC
pharynx
external  internal digestion, diffusion

5. Phylum Platyhelminthes Feeding in parasitic flatworms
feed on blood, tissue fluids, pieces of cells within host
no need for complex digestive system
Clonorchis sinensis (human liver fluke)
Taenia saginata (beef tapeworm)

6. Phylum Platyhelminthes Respiration, circulation, excretion
diffusion
flame cells - remove nitrogenous metabolic wastes and excess H2O

7. Phylum Platyhelminthes Response
ganglia
nerve cords (ladder-like)
eyespots
sensory cells

8. Phylum Platyhelminthes Movement
Muscles
Ventral epidermal cilia + mucus

9. Phylum Platyhelminthes Reproduction
Free-Living
Fission and regeneration
Hermaphroditism and cross-fertilization

10. Phylum Platyhelminthes Reproduction
Parasitic
Complex life cycles with both asexual and sexual reproduction
(Schistosoma japonicum)

11. Phylum Platyhelminthes
Class Turbellaria
free-living flatworms
Dugesia
Class Trematoda
flukes
Schistosoma
Class Cestoda
Tapeworms
Taenia
Diphyllobothrium

12. Tapeworm structures Long, flat, parasitic worms Structure
Scolex: head w/ suckers, hooks
Proglottids: body segments that produce both sperm and egg

14. Phylum Nematoda Roundworms
with tissues  organ systems
“tube within a tube”
triploblastic
bilaterally-symmetric
with cephalization
pseudocoelomates ,

15. Phylum Nematoda Feeding in nematodes
carnivores/ detritivores or parasites
complete digestive system
internal digestion, diffusion

16. Phylum Nematoda Respiration, circulation, excretion
diffusion through epidermis and cuticle
with an excretory canal and pore

17. Phylum Nematoda Response
circular nerve ring  primitive brain
dorsal and ventral nerve cords

18. Phylum Nematoda Movement
muscles
hydrostatic skeleton

19. Phylum Nematoda Reproduction
Sexual: Internal fertilization
Asexual: Parthenogenesis
unfertilized egg develops into an adult organism without sperm fertilization

20. Phylum Nematoda Reproduction
Parasitic
Complex life cycles (Trichinella spiralis)

21. Phylum Nematoda Reproduction
Parasitic
Complex life cycles
Filarial worms
(Brugia malayi)
threadlike
blood and lymph vessels of birds and mammals
vector: biting insects
with symbiotic bacteria Wolbachia

22. Phylum Nematoda Reproduction
Parasitic
Complex life cycles
Ascaris spp.
causes malnutrition in >1B people

23. Phylum Nematoda Reproduction
Parasitic
Complex life cycles
Hookworms
Infects ~1/4 of the world’s population