1. Platyhelminthes
Flatworms

2. Phylum Platyhelminthes

4. Flatworms Phylum Platyhelminthes One opening (mouth) Flatworms
Tapeworms (parasite)
Flukes (parasite)
Planarians

5. Platyhelminthes Simplest animal with bilateral symmetry
Acoelomates – do not have a body cavity
Develops from three germ layers
Endoderm
Mesoderm
Ectoderm

6. Class Turbellaria Class Turbellaria = Planarians Home
Live mostly in the ocean
Some live in freshwater

7. Feeding Uses tube-like organ muscular organ = pharynx
Release enzymes from pharynx that begin to digest food
Food sucked into digestive tract
Finish digesting food in the gastrovascular cavity
Cells use endocytosis to get food

8. Respiration & Circulation
Occur by diffusion
Thin bodies allow for easy access for all cells to outside environment

9. Excretion Mouth expels solid waste
Flame cells = cells that collect and excrete excess water
Called flame cells because they look like candles
Cilia push water out of cell

10. Response Show cephalization Nervous system in head = Ganglia
2 nerve cords
Eyespots
Sensory cells

11. Movement Glide over surfaces on a mucus that they secrete
Swim with cilia

12. Reproduction & Regeneration
Sexual or asexual
Hermaphrodites
Regeneration – can regrow parts

13. Class Trematoda Nervous and excretory systems like turbellarians
Hermaphrodites
Have complex life cycles

14. Class Trematoda Are parasitic flukes
Have suckers on both ends of the body
Can live inside or outside of host

15. Flukes – Life Cycle

16. Class Cestoda Parasitic Tapeworms Long, ribbon-like bodies
Absorbs nutrients from host
Hermaphrodites

17. Tapeworm Anatomy Scolex – knob-shaped head with hooks and suckers.
Attach to intestinal lining of host and absorbs food
Proglottids – detachable sections
Eggs
Testes