Download presentation
Presentation is loading. Please wait.
1
Flatworms Phylum Platyhelminth
2
Endoparasite
3
Exoparasite / Ectoparasite
4
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
5
Clonorchis
6
Flatworms Name means flat worm
7
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
8
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
9
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
10
Class Turbellaria Planarians Free living
Most often found in fresh water Eyespots sense light
11
Some can split asexually by fission
12
Planarian
13
Planarian Pharynx is responsible for obtaining food
Extends out and releases proteolytic enzymes (breaks down protein) External digestion
14
Class Trematoda Parasitic flukes Generally endoparasites
Poorly developed sense organs Generally have suckers but no hooks
15
Life cycle of the liver fluke
16
Fluke
17
Paragonimus westermani
The lung fluke parasite Causes paragonimiasis
18
Clonorchis
19
Clonorchis Common in the Orient Can cause cirrhosis of the liver
20
Schistosomiasis
21
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
22
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
23
Tapeworms Completely lack a digestive system and sense organs
Generally have more than one host
25
Tapeworm cyst in the liver
26
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
28
Dog Tapeworm
29
Pork Tapeworm - Taenia solium
30
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.
32
You need: Planaria – digestive or plain Clonorcis Schistosome Taenia
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.