1. Trematode

2. Trematode Trematode is a class in phylum Platyhelminthes.
There lifecycle is complex, so they require two or three host for reproduction.
species.

3. Anatomy
There length varies from millimeters to centimeters i.e. 1 mm- 7 cm.
Two suckers are present, one is close to mouth and other is present dorsal side.
Tegument form the protective layer so, which provide protection against digestive enzymes in host.
No respiratory organ is present.
Mouth is attach with pharynx and esophagus and intestinal and no anus is present so waste material excreted out through mouth.
Excretory system is present which mainly concerned with osmoregulation.

4. Cont. 3 pairs of ganglia are present in brain.
No sensory organs are present.
Reproductive system contains two testes and ducts from which sperm come out and also contain storage sacs for sperms.
Mostly single ovary is present. Egg pass from it to oviduct which is attach with uterus.

6. Liver fluke These also called flatworms and shape is like a leaf.
These are the parasites of liver of various mammals including humans.
Life cycle required 2- 3 hosts.

7. Life Cycle

9. Eggs

10. Paragonimus westermani
These causes lung infection in humans i.e. Paragonimasis.
Unembryonated egg pass through feces or sputum.
Life cycle consist of two hosts.

12. Life cycle

13. Eggs

14. Fasciolopsis buski
It’s causes intestinal infection known as fasciolopsiasis.
Humans and pigs.
Size is 7 cm long and width is about 2.5 cm.
27000 egg per days.

17. Life cycle

18. Eggs

19. Schistosoma Japonicum
Causes schistosomasis.
Infection by schistosomes is followed by an acute Katayama fever. 
Most common in China, Philippine and Srilanka
If left untreated, it will develop into a chronic condition of hepatosplenic disease and impaired physical and cognitive development.  
Neurological diseases in schistosomes due to the migration of schistosome eggs to the brain.

21. Life cycle

22. Egg