1. Eumetazoa - animals with tissue
Phylum Platyhelmenthes (the flatworms)
General characteristics
Eumetazoa - animals with tissue
Bilateria - have bilateral symmetry
Head end-cephalization
Tail end
Right and left side
Top (dorsal) and bottom (ventral)
triploblastic -ectoderm, mesoderm, endoderm.
Protostomia - a group of animals whose mouth develops from the blastopore, and the mesoderm forms from an area near the blastopore.
Acoelomata - They have a true mesoderm which fills the original blastocoel between the outer epidermis and digestive tract.

2. Integumentary- Rhabdites and one cell layer epidermis in Turbellaria and usually ciliated; syncytial tegument in other classes.
Skeletal - hydrostatic
Muscle - longitudinal, transverse, and circular muscles are present.
Digestive - incomplete with intracellular and extracellular digestion; no system in Cestoda.

3. Excretory - flame cells, or excretory tubes in Cestoda.
Respiratory - no system, diffusion
Circulatory - none, diffusion.
Nervous - anterior ganglia, ventral ladder-like system (two lateral cords with transverse cords).
a bilobed anterior ganglial mass (brain)

4. Protonephridia-a series of flame cells
that aid in excretion

5. Endocrine - hormones produced by nervous system
Reproductive - monoecious in most
Well developed reproductive organs, mostly internal fertilization.
Two of the parasitic classes have complex life cycles
Trematoda -
Cestoda -

6. Class Turbellaria-
~5000 species, mostly free-living
~Dugesia- free living planarian
Branched gut

7. Reproduction-
asexual- fission
sexual - monoecious
Diversity-land planarian- Bipalium

10. Gone fission

12. Branched gut
eyespots

13. Class Trematoda--flukes
~parasitic
endoparasitic
ectoparasitic
~tegument=body wall
~suckers
~feed on host cells, tissue fluids, mucus (yuk!) and blood
~life cycle
monogenic flukes
digenic flukes

14. Opisthorchis - Human liver fluke

15. Schistosoma --- swimmer’s itch

17. Class Cestoda = tapeworms
Proglottids-
Head-scolex

18. Scolex
proglottid

19. Proglottid- note interconnection

20. Scolex

21. Life cycle

24. Phylum Nemertina- ribbon worms
Proboscis can be extruded to capture food

25. General characteristics-
~tube within a tube body plan- a complete digestive tract
~Acoelomate
~eversible proboscis, within a rhinocoel above the gut
~feeding-stylets and toxins
~closed circulator system, a single dorsal vessel with two lateral
vessels
~paired lateral longitudinal nerve cords

26. ~asexual reproduction by fragmentation
dioecious
free-swimming larva in some marine species
Advanced Features-
~anus
~closed circulatory system
~dorsal nerve cord in some
~complex excretory system in close association with circulatory system
~mesodermally derived blood vessels & mesodermally lined
rhinocoel may provide links to higher phyla