1. Worms- Ch. 14,15, 16Phylum Platyhelminthes
Link to video Link to video

2. Flatworms - General Information
Symmetry: Bilateral
Cephalization- head end concentrated with sense organs and nervous control
Tripoblastic- has a middle germ layer (mesoderm) as well as ectoderm and endoderm
Parasitic in nature
Examples of Flatworms include: planaria, flukes, and tapeworms
4 Classes : Turbellaria(Planarians), Trematoda (Flukes), Monogenea and Cestoda(Tapeworms)

3. Class: Turbellaria - Body Form
Ciliated epidermis
Rod- shaped Rhabdites- swell and form a protective mucous sheath around the body
Dual gland adhesive organs in the epidermis

5. Class Monogenea, Tremotoda, and Cestoda – Body form
Parasitic
Non-ciliated body covering
Ciliated covering is lost once a host is contacted

6. Digestive System: Includes a mouth, pharynx, and an intestine
GVC- Gastrovascular cavity present
Mainly carnivorous – feed on small crustaceons, nematodes, rotifers, and insects
Flatworms have a system called: protonephridia/ can be used for osmoregulation or excretion
System is mainly osmoregulatory ( regulates the water inside and outside of the body)
Flame Cells- cup shaped cell that has flagella extending out

7. Flame cells act like a kidney, filtering and removing waste materials
Flame cells act like a kidney, filtering and removing waste materials. It is the simplest form of an excretory system.

8. Nervous System-
Simple nervous system (found in turbellarians) – Subepidermal Nerve Plexus similar to the nerve net in cnidarians
May also have one to five pairs on longitudinal nerve cords lying under the muscle layer
Have ganglia and neurons
SENSE ORGANS:
Ocelli: light sensitive eyespots
Tactile Cells -touch
Chemoreceptive cells
Statocysts for equilibrium
Rheorecptors- sensing direction in water currents

9. Cerebral ganglion is the brain, organizing sensory-, motor- and inter- neurons.

10. Reproduction and regeneration:
Reproduce both sexually and asexually (fission) same as budding like the hydra
Almost all flatworms are monoecious
Some have spiral determinate cleavage typical of protostomes

11. Class Turbellaria – extra information
Often distinguished on the basis of the form of the gut ( present or absent? , simple or branched?, pattern of branching? )
Creeping forms that combine muscular with ciliary movements to move

12. Class Trematoda All parasitic flukes Leaflike in form
Penetration glands / organs for adhesion to hosts like suckers and hooks
Increased reproduction capacity
Sense organs are poorly developed
EX: Liver Fluke in Humans ( common in regions of east Asia, especially China, Southeast Asia, and Japan; also common in cats, dogs, and pigs.)
Blood Fluke (causes schistosomiasis)

13. Life cycle of a fluke

14. Class Monogenea
Are all parasites ( on fish, frogs, turtles, and one on the eye of a hippopotamus)
Cause little damage to hosts
Can be serious if many hosts are crowded together (farm- raised fish)

15. Class Cestoda- Tapeworms Long, flat bodies
Has a scolex(for attachment to host)- has suckers/ tentacles for attachment , and proglottids ( linear series of reproductive units)
No digestive system
Well-developed muscles
Excretory system is similar to other flatworms as well as nervous system
No special sense organs
No head

18. Examples of Cestoda : Beef Tapeworm, Pork Tapeworm, Fish tapeworm, Dog Tapeworm

19. Often called ribbon worms
Phylum Nemertea
Often called ribbon worms
Long muscular proboscis
Bilateral
Triploblastic
1000 species; all marine
Complete digestive system

20. Ribbon worm, using proboscis, swallowing prey.

21. Rotifera (rotifers)
Free-living aquatic animals. Many attach to substrates with their “foot”.
Pseudocoelomate
Complete digestive system, excretory system and reproductive system all empty into cloacal bladder.

22. Acanthocephala Spiny-headed worms. Cylindrical, spined proboscis
Parasitic
Excretory system
No digestive tract
Dioecious

23. Annelids link

24. Ch. 17 P. Annelida
Segmented Worms – Each segment contains similar components of all major organ systems
Annuli- Circular Rings that give this phylum their name
Setae- Chitinous bristles ( exception: leeches) Eww!
Freshwater dwelling – Oligochaetes (Earthworms and Leeches)

25. Body Plan Two part head region - Prostomium and Peristomium
Terminal portion: pygidium which contains an anus
Each segment contains: 1) circulatory, 2) respiratory, 3) nervous, 4) Excretory 5) coelom
Peritoneum lines the body wall of each compartment
Hydrostatic Skeleton: coelom is filled with fluid

26. Triploblastic- 3 Germ Layers
Coelom well developed
Bilateral symmetry
Nervous System: double ventral nerve cord, ganglia, Brain
Sensory system: Tactile (touch) organs, taste buds, photoreceptor cells

27. Reproduction Methods Asexually by fission Can completely regenerate
Sexually- Monoecious – having both male and female organs
2 Classes have Clitellum( region of body) which aids in sexual reproduction

28. 3 Classes: 2) C. Hirundinida –Leeches
1) C. Oligochaeta
2) C. Hirundinida –Leeches
3) C. Polychaeta ( paraphyletic group) What does THAT mean?
Groups 1 and 3 share a common feature:
Reproductive structure called a clitellum

29. Environments:
Marine, Freshwater, and Land (terrestrial)