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Trematodes



Schistosoma Mansoni: Example of Tramatode

What are

Trematodes are parasitic worms belonging to the phylum Platyhelminthes. They are scientifically classified as Trematoda Class.

Main characteristics of trematodes

- They have simple body.

- They are acelomated worms (mesoderm-coated embryonic cavity)

- They have a flat-shaped body.

- They are parasitic animals of humans and other animals.

- It has two suction cups (one around the mouth and one in the belly), used to fix your body on the host.

- They have bilateral symmetry.

- They have no circulatory and respiratory system.

- Presence of protective film on the epidermis.

- Have incomplete digestive system.

Life cycle (example: Schistosoma Mansoni)

Adult (female) trematodes produce eggs that are placed in the definitive host (male).

The eggs mix up the feces in the human intestines. These, when eliminated with the feces and come into contact with water, hatch, giving birth to larvae.

Larvae can enter snails (genus biomphalaria) and reproduce, giving rise to thousands of other larvae called cercariae. These can leave the snail (intermediate host) and penetrate the human skin, reaching the bloodstream and the hepatic system, where they will develop into the adult and sexual phase.

Trematode Examples

- Schistosoma Mansoni: A parasite that causes a disease called schistosomiasis in humans. They live mainly in the gut region of the hosts.

- Liver fasciola: parasite that lives in the liver of sheep.