2.  Flatworms › Phylum-  Platyhelminthes › Class-  Turbellaria, Cestoda, Trematoda, Monogenea › Families-  102 variations  Roundworms › Phylum-  Nematoda › Class-  Adenophorea, Secernentea, › Families-  A LOT (Pseudoceros bimarginatus) (Enterobius vermicularis)

3.  Flatworms: › Scientists don’t really know › Parasitic flatworms probably evolved from free-living animals  Roundworms: › Scientists believe the roundworms lived somewhere in the Proterozoic Era (1+ billion years ago)

6.  Flatworms:  Bilaterally symmetrical  3 germ layers – ecto-, meso-, endo-, -derms that press against each other  Gastrovascular cavity-gut with 1 opening  Acoelomates- lack a hollow body cavity  Roundworms:  Bilaterally symmetrical  Pseudocoelomates-have a hollow fluid filled cavity lined by mesoderm outside and endoderm inside

7.  Flatworms:  Varying structural systems including proglottids or sections, tegument or an outer layer of proteins and carbohydrates  Roundworms:  Hydrostatic skeleton

8.  Flatworms:  Turbellarians, monogeneans, and trematodes have a digestive system, but cestodes don’t  Mouths are on the front or side of the head  Turbellarians are always non- parasitic, while monogeneans, trematodes and csetodes are parasites, usually found on or inside an organism  Flatworms eat small worms, insects and microscopic matter  Roundworms:  Can be herbivores, omnivores, or carnivores  Mouth to pharynx to intestine to anus

9.  Flatworms:  No formal circulatory system  Cilia & muscles  Roundworms:  Use muscles and the fluid in their pseudocoelum to make a “hydrostatic skeleton”  Aquatic worms use these muscles to swim, while terrestrial worms thrash around  No formal circulatory system

10.  Flatworms:  No formal respiratory system  Being extremely thin, flatworms can exchange gases, mainly oxygen and carbon dioxide, directly with their environment through diffusion  Roundworms:  No formal respiratory systems  Oxygen is diffused through the environment

11.  Flatworms:  Excretion & eating both use the same opening  Protonephredia and flame cells regulate water balance  Water balance or osmoregulation is maintained by protonephridia, which terminate in specialized flame cells  Roundworms:  Fecal matter exits through the anus

12.  Flatworms: › Sexual:  Fertilization is internal  Eggs are ectolecithal; the ova are provided with yolk cells and the egg mass is surrounded in a capsule. › Asexual  Very frequent  Turbellarians reproduce by fragmentation or binary fission.  Roundworms: › Sexual:  Males have testes, where females have ovaries  Fertilization is internal

13.  Flatworms: › Organizaton of ganglia is a central region of nerve processes. › Nerve cords are usually arranged in symmetrical pairs.  Roundworms: › Consist of a large circumesophageal commissure -nerve ring. › There are commissures that interwoven the ventral nerve cord with the lateral or dorsal nerves › Lateral nerves are primarily sensory. › The dorsal and ventral nerve cords are motor.

14.  Flatworms: › They are studied for their regenerative abilities. › Cause pathological troubles or difficulty in marine ornamental fishes.  Roundworms: › Parasitic adenophoreans aid plants in receiving diseases. › cause dehydration and loss of nutrition in plants. › Help to cycle carbon and nitrogen

15.  Starnes, Robert (2002). Flatworms and roundworms. Retrieved April 11, 2009, from Essortment Web site: http://www.essortment.com/all/flatwormroundwo_rmhm.htmhttp://www.essortment.com/all/flatwormroundwo_rmhm.htm  Flatworms. Retrieved April 11, 2009, from Flatworm Web site: http://www.mcwdn.org/Animals/Flatworm.html http://www.mcwdn.org/Animals/Flatworm.html  Klaus Rohde, C. G. Goodchild, "Platyhelminthes", in AccessScience@McGraw-Hill, http://www.accessscience.com, DOI 10.1036/1097-8542.527600  (2006). University of Winnipeg EVOLUTION ECOLOGY AND BIODIVERSITY. Retrieved April 11, 2009, from PHYLUM NEMATODA Web site: http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb5pg8.htm http://kentsimmons.uwinnipeg.ca/16cm05/16labman05/lb5pg8.htm  Preisner, Thadd R. (2007, February 5). Flatworms. Retrieved April 11, 2009, from PENN STATE UNIVERSITY Web site: http://www.personal.psu.edu/users/t/r/trp2/flatworms.htmlhttp://www.personal.psu.edu/users/t/r/trp2/flatworms.html  "Turbellarians: Turbellaria." Grzimek's Student Animal Life Resource. Ed. Catherine Judge Allen, Arthur V. Evans, Melissa C. McDade, Neil Schlager, Leslie A. Mertz, Madeline S. Harris, et al. Vol. 9: Corals, Jellyfishes, Sponges, and Other Simple Animals. Detroit: UXL, 2005. 78-87. Gale Virtual Reference Library. Gale. VERNON HILLS HIGH SCHOOL. 11 Apr. 2009 http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182  "Roundworms: Adenophorea." Grzimek's Student Animal Life Resource. Ed. Catherine Judge Allen, Arthur V. Evans, Melissa C. McDade, Neil Schlager, Leslie A. Mertz, Madeline S. Harris, et al. Vol. 9: Corals, Jellyfishes, Sponges, and Other Simple Animals. Detroit: UXL, 2005. 132-136. Gale Virtual Reference Library. Gale. VERNON HILLS HIGH SCHOOL. 11 Apr. 2009 http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182http://go.galegroup.com/ps/start.do?p=GVRL&u=vern39182  Postlethwait, John H. (2006). Modern Biology. Austin, TX: Holt, Rinehart and Winston.