Flatworms Phylum Platyhelminth. Endoparasite Exoparasite / Ectoparasite.
-
Upload
lambert-potter -
Category
Documents
-
view
230 -
download
0
Transcript of Flatworms Phylum Platyhelminth. Endoparasite Exoparasite / Ectoparasite.
Flatworms
Phylum Platyhelminth
Endoparasite
Exoparasite / Ectoparasite
Life cycles
Most parasitic worms have more than one organism in their life cycle: An intermediate host (the first), usually a mollusk Sometimes there are multiple intermediate hosts A final (definitive host), usually a vertebrate These hosts are where sexual reproduction occurs
Clonorchis
Flatworms
Name means flat worm
Flatworm advancements
First animals to show bilateral symmetry First animals to have 3 well defined germ
layers (called tripoblastic) Are considered acoelomate (no body
cavity) Simple sense organs with eye spots in
some
Advancements, continued
First animals to show cephalization – having a clear and defined head with most of the important structures found there
First to have an excretory system First to have a circulatory system with
blood
Characteristics
Oral and genital structures found mostly on the ventral surface
Digestive system incomplete Simple sense organs Nervous system with a central processor (brain) Most organisms monoecious, some with
complicated life cycles
Class Turbellaria
PlanariansFree livingMost often found in fresh waterEyespots sense light
Some can split asexually by fission
Planarian
Planarian
Pharynx is responsible for obtaining food Extends out and releases proteolytic
enzymes (breaks down protein)External digestion
Class Trematoda
Parasitic flukes Generally
endoparasites Poorly developed
sense organs Generally have
suckers but no hooks
Life cycle of the liver fluke
Fluke
Paragonimus westermani
The lung fluke parasite Causes paragonimiasis
Clonorchis
Clonorchis
Common in the Orient Can cause cirrhosis of the liver
Schistosomiasis
Schistosomiasis
Blood fluke 200 million people infected Causes severe dysentery, anemia,
bladder inflammation and brain damage There is also a kind that infects birds that
causes “swimmer itch” a rash
Class Cestoda
Tapeworms Long flat bodies made up of an attachment
head with hooks and suckers, called scolex
The scolex is followed by MANY reproductive segments called proglottids
Tapeworms
Completely lack a digestive system and sense organs
Generally have more than one host
Tapeworm cyst in the liver
Beef Tapeworm
Larvae shed from the human host are eaten by cattle
Larvae hatches and encysts in the muscle People eat un- or undercooked meat and
the larvae hatches in the intestines
Dog Tapeworm
Pork Tapeworm - Taenia solium
Question……
What is the world's longest parasite? The world's longest parasite is the tapeworm so the
next question is 'What is the world's longest tapeworm?'
The longest tapeworm ever removed from a human came out of Sally Mae Wallace on September 05, 1991.
In all, doctors pulled 37 feet of tapeworm out of Sally Mae Wallace's body
If you find all of this disgusting, be glad you're not a whale as tapeworms in whales can grow up to 120 feet long.
You need:
Planaria – digestive or plain Clonorcis Schistosome Taenia