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Phylum Annelida (segmented worms). OMG! (gosh) A COELOM. Very successful phylum. ANYONE SEEN THESE SCUBA DIVING? Polychaete s . Let ’ s start with what we know- EARTHWORMS. Developmental Stages. What does it mean to say that an earth worm is a protostome? Develops mouth first.
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Phylum Annelida (segmented worms) • OMG! (gosh) A COELOM
Very successful phylum ANYONE SEEN THESE SCUBA DIVING? Polychaetes.
Developmental Stages • What does it mean to say that an earth worm is a protostome? • Develops mouth first. ONLY BILATERAL ANIMALS CAN BE CLASSIFIED AS PROTOSTOME OR DEUTEROSTOME
http://www.google.com/imgres?hl=en&client=firefox-a&hs=y32&sa=X&rls=org.mozilla:en-US:official&biw=1252&bih=559&tbm=isch&prmd=imvns&tbnid=G0SSnPzx0rKmmM:&imgrefurl=http://home.sandiego.edu/~gmorse/2011BIOL221/biol221_studyguide3.html&docid=GI44bgG4dKVU_M&imgurl=http://home.sandiego.edu/~gmorse/2011BIOL221/biol221_studyguide3/coelom.jpg&w=420&h=505&ei=yQwVT6ybCemWiAKRoNilDQ&zoom=1&iact=rc&dur=244&sig=101830522278361665895&page=1&tbnh=156&tbnw=130&start=0&ndsp=10&ved=1t:429,r:9,s:0&tx=43&ty=97http://www.google.com/imgres?hl=en&client=firefox-a&hs=y32&sa=X&rls=org.mozilla:en-US:official&biw=1252&bih=559&tbm=isch&prmd=imvns&tbnid=G0SSnPzx0rKmmM:&imgrefurl=http://home.sandiego.edu/~gmorse/2011BIOL221/biol221_studyguide3.html&docid=GI44bgG4dKVU_M&imgurl=http://home.sandiego.edu/~gmorse/2011BIOL221/biol221_studyguide3/coelom.jpg&w=420&h=505&ei=yQwVT6ybCemWiAKRoNilDQ&zoom=1&iact=rc&dur=244&sig=101830522278361665895&page=1&tbnh=156&tbnw=130&start=0&ndsp=10&ved=1t:429,r:9,s:0&tx=43&ty=97
Advantages of a Coelom - independent movement of body wall and enclosed organs - more space for complex organs and organ systems- storage area for eggs and sperm. -It also contains fluid that protects internal organs, and can provide oxygen and nutrients to cells, collect wastes, and function as a hydrostatic skeleton.
Movement via Setae (also called Chaetae) • The worms anchor the Setae to create friction. They then elongate and contract accordingly. http://tolweb.org/Annelida
Digestion http://www.google.com/imgres?hl=en&client=firefox-a&sa=X&rls=org.mozilla:en-US:official&channel=np&biw=1252&bih=586&tbm=isch&prmd=imvns&tbnid=Pi_hsie8XXSkVM:&imgrefurl=http://www.tutorvista.com/content/biology/biology-iv/animal-nutrition/holozoic-nutrition.php&docid=r4fIVUC2U-V1gM&imgurl=http://images.tutorvista.com/content/animal-nutrition/digestive-tract-earthworm.jpeg&w=341&h=275&ei=wIocT6_nJMWqiAKjstDHCA&zoom=1&iact=hc&vpx=934&vpy=170&dur=1745&hovh=202&hovw=250&tx=140&ty=111&sig=101830522278361665895&page=1&tbnh=110&tbnw=136&start=0&ndsp=22&ved=1t:429,r:7,s:0 • Mouth Pharynx Esophagus Crop Gizzard Intestine Anus • More evolved digestive system.
Circulation • First heart that we have seen • Simple closed circulatory system • Along with nematodes, annelida have developed hemoglobin. In these animals it floats freely in the blood and is not attached to cells.
Blood is pumped by the 5 hearts through the Ventral Vessel and then returns via the dorsal (back) blood vessel. http://sciencenotes.wordpress.com/2012/01/21/traces-of-evolution/
Respration • DIFFUSION through body wall • Must keep its cuticle moist!
Reproduction Get a Room!
Reproduction • Even though worms are hermaphroditic most reproduction is sexual. • They align their Clitellum's • clitellum secrets mucus ring to release sperm fertilization. Eggs are then transported to the sperm.
Excretion • Nephridia- coiled tubes • The tubule opens to the outside through the body wall. Filtration of the blood across the tubule wall can occur because of the close association between capillaries and the nephridium.
Reading • Hand out earthworm labelling sheet
Dissection time • A reminder of vocabulary for dissection.