Platyhelminthes flatworms Cestoda tapeworms w Turbellaria free living

Platyhelminthes: flatworms Cestoda: tapeworms w Turbellaria: free living flatworms like Planaria w Trematoda: flukes like Schistosoma w

Platyhelminthes w Have bilateral symmetry w Can be free living or parasitic w Have 3 germ layers and are acoelmate (lacking a cavity between gut and outer wall) w Move by using cilia or by contracting their muscles

Platyhelminthes: fluke life cycle w. Schistosoma Life Cycle- Sheep liver fluke

Tapeworm: Cestoda w Tapeworm scolex tapeworm

Turbellaria; planaria (free living)

More turbellarians

Flatworm videos http: //www. youtube. com/watch? v=vo. MKJe a 91 gg free living flatworm w http: //www. youtube. com/watch? v=Ich 4 Y_ K 6 Gu. M&feature=Play. List&p=E 9 E 109312 4 E 2 F 9 C 9&playnext=1&index=11 planaria eating w http: //www. youtube. com/watch? v=T 6 p. Af. Q Inf 2 c tapeworm in intestine w

Phylum Rotifera Are tiny animals that mainly inhabit fresh water, although some live in the sea or in damp soil. w Have bilateral symmetry and are truly multicellular. w “Rotifer, ” derived from Latin, means “wheel-bearer”—a reference to the crown cilia that draws a vortex of water into the mouth. w Pseudocoelomate w http: //www. youtube. com/watch? v=OSo. Fw. Ck. Tbj 0&feature=related

Phylum Rotifera Have specialized organ systems—including a complete digestive tract: with a separate mouth and anus. w Perform a type of reproduction called parthenogenesis (virgin birth): females producing more females from unfertilized eggs. w

Nematoda: roundworms Complete digestive tract w Pseudocoelomate w Hydrostatic skeleton under pressure which means only one shape is possible w Longitudinal muscles allow for wriggling, but no circular muscles w

Phylum Nematoda Reproduction is usually sexual—females are generally larger than males. w Fertilization is internal, and a female can deposit 100, 000 or more fertilized eggs per day. w The zygotes of most species are resistant cells capable of living in harsh conditions. w Hookworm

Roundworms Pinworm Ascaris: intestinal roundworm 1, 000 cases in USA: 1. 2 billion worldwide Heartworm

Ascaris life cycle

Removal of Guinea Worm http: //www. youtube. com/watch? v=m. Uz 9 gq. Lmy. Q 0

nematodes http: //www. youtube. com/watch? v=JBLem M 3 tz. RM soil nematodes w http: //www. youtube. com/watch? v=gm. FHn QKb. SM 8 lymphatic filariasis (elephantiasis) 1 billion worldwide w

Annelida: segmented worms Eucoelomate w Segmented body plan w Closed circulatory system w Protostome w

Annelida: key structures Metanephridia: kidney like structures w Setae/ parapodia w Clitellum w Aortic arches w

leeches Fused segments to allow for blood storage w Blood thinner released to help sucking w

http: //www. youtube. com/watch? v= DZig 6 EL 5 B 6 A&feature=Play. List &p=F 648 EFCC 1 BE 6 AAA 3&playn ext=1&index=10 Earthworms in Australia Earthworms are hermaphroditic. They fertilize each other with the clitellum secreting a mucus sack to collect the eggs and sperm. This sack is then placed into the ground until babies are developed.