Platyhelminthes
Kim Paul
Emelie Poirier
Chloe Raitt
Hailey Reagh
Introduction
 Platyhelminthes
 Flatworms
 20,000+
known species
 Range in length
 Feed on animal material, algae
 Bilaterally symmetrical
 3 cell layers
 Mostly hermaphroditic
 Live everywhere
 Moist environments
Evolution
 Soft,
small bodies don’t produce a well
fossilized record.
 Schistosome larvae, oldest subspecies
found, discovered in Egyptian Mummies.
 Nothing concrete found before them.
 Believed to have first appeared around
550 MYA.
Evolution
 Biochemical
aspects used to determine
Tree of Life.
 Still discrepencies in Tree of Life with taxon
relationships.
 Parasitic subgroup (Trematoda,
Monogenea, and Cestoda) are believed
to be monophyletic
 Acoela are believed to have a different
ancestor.
Classification
 Phylum
– Platyhelminthes
 Greek words
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Platy for flat
Helminthes for worm
 Classes
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Cestoda (parasitic tapeworms)
Trematoda (parasitic flukes)
Turbellaria (free living Planaria)
Major Subgroups
Turbellaria
Trematoda
Cestoda
Turbellaria
 Free-living
group
 Mostly benthic and marine
 Over 4000 species
Trematoda
 Group
of parasites
 9000 species have been
discovered
 Worm-like or flattened
oval
 Human liver flukes and
blood flukes
Cestoda
 Parasites
 5000
known species
 Long and flat bodies
Characteristics
 Unsegmented
bodies
 Lack of skeletal system
 Lack of circulatory system
 Lack of body cavity
 Locomotion
 Nervous system
 Digestive system
Fun Facts!

Both salt water and freshwater

Tolerant of pollution

Come in great lengths

Withstand starvation

Simplest form of the worm

Regenerate

Reproduce sexually and asexually
References
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Platyhelminthes. Gerlinger, Friedrich. Web.
http://home.arcor.de/gerber.7/platyhelminthes.htm
Flatworm – Parasites. O’Shea, Lorraine. Web.
http://poster.4teachers.org/view/poster.php?poster_id=379778
Ramel, Gordon (n.d). The Phylum Platyhelminthes. Earthlife. March 4, 2013, from
http://www.earthlife.net/inverts/platyhelminthes.html
Target Informatics Pvt. Ltd. (2013). Platyhelminthes. Target Study. March 4, 2013,
from http://targetstudy.com/nature/animals/platyhelminthes/
http://www.ucmp.berkeley.edu/platyhelminthes/platyhelminthes.html
http://www.naturwissenschaften.be/en/institute/associations/rbzs_website/bjz/
back/pdf/BJZ%20131%28s1%29/Volume%20131%28s1%29,%20pp.%203546.pdf http://www.cisnerosheredia.org/infotrans/usfq/zoologia/pdfs/rohde2001.pdf
Campbell, A. 2001. "Turbellaria" (On-line), Animal Diversity Web. Accessed
March 06, 2013 at
http://animaldiversity.ummz.umich.edu/accounts/Turbellaria/
Myers, P. 2001. "Trematoda" (On-line), Animal Diversity Web. Accessed March
06, 2013 at http://animaldiversity.ummz.umich.edu/accounts/Trematoda/
Myers, P. 2001. "Cestoda" (On-line), Animal Diversity Web. Accessed March 06,
2013 at http://animaldiversity.ummz.umich.edu/accounts/Cestoda/
McDarby, Michael. (2001-2013). Flatworms(Platyhelminthes). An Online
Introduction to the Biology of Animals and Plants. March 6, 2013, from
http://faculty.fmcc.suny.edu/mcdarby/animals&plantsbook/animals/03Flatworms.htm
Photos
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http://species.wikimedia.org/wiki/Platyhelminthes
http://planet.uwc.ac.za/nisl/biodiversity/loe/page_20.htm
http://quizlet.com/4357176/platyhelminthes-nematodes-rotifers-flash-cards/
http://skepticalsquirrel.wordpress.com/2012/07/28/backwards-before-we-goforwards/
http://egy-king.blogspot.ca/2012/09/ancient-egyptian-mummies.html
http://www.rzuser.uni-heidelberg.de/~bu6/Introduction11.html
http://www.elasmodiver.com/images/flat-worm.jpg
http://sharonapbio-taxonomy.wikispaces.com/Animalia-Platyhelminthes
http://www.richardseaman.com/Underwater/Philippines/Nudibranchs/index.html
http://www.starfish.ch/c-invertebrates/flatworms.html
http://biodidac.bio.uottawa.ca/thumbnails/filedet.htm?File_name=Trem054p&Fil
e_type=gif
http://eol.org/pages/2885/overview
http://www.rzuser.uni-heidelberg.de/~bu6/pow.html
http://www.dscc.edu/bwilliams/biology%201120/biol_1120_lab_animals
http://fineartamerica.com/featured/a-beautiful-flatworm-feeds-on-algae-terrymoore.html
http://www.darwinsgalapagos.com/animals/platyhelminthes_flatworms.htm
http://www.waterworxbali.com/flatworms.shtml
http://www.tranquil-seas.com/?_escaped_fragment_=portfolio