Types of Parasites with 21 Examples

The parasite is any organism that derives nourishment and other benefits from others.

Here, the organism giving benefit is called the host, and the one receiving is called the parasite.

The host is the loser, while the parasite is the gainer.

Hence, the host may be severely affected due to parasites.

Parasites are present in both plant and animal kingdoms.

Few plants, microbes, and many animals act as parasites.

A parasite can infect plants, animals, or even microbes.

Many parasites cause severe diseases in humans.

Types of parasites

l. Ectoparasites

These are the parasites that live outside the body and derive nutrition.

Ex: Head louse, Bed mites, leech, etc.

They do not cause diseases in humans but can help spread diseases like plague and cause irritation to the body.

2. Endoparasites

These are the ones that live inside the host body. So they can be more dangerous and life-threatening.

Based on where they live inside the body, they are further classified as

a. Cytozoic parasites

These parasites live within the cells of the host.

This mostly includes protozoan parasites, viruses, and a few bacteria.

They are the best examples of the single-celled parasites.

Types of parasites
Plasmodium inside Red Blood cells (By: Ed uthman/flickr)

Ex: Malaria at protozoal parasite resides inside the red blood cells and live cells.

b. Inter-cellular parasites

As the name indicates, these parasites live between the spaces of host body cells.

Entameoba in intestine tissue
Entameoba in intestine tissue: www.cdc.gov

Ex: Entamoeba hystolytica, which causes diarrhea.

c. Coelozoic parasites

These parasites live in the body cavities.

Ex: Tapeworms and worms live in the intestines of humans.


They derive the nutrition from the intestine and reside there for years if untreated.

3. Obligate parasites:

These parasites exist only as parasites. i.e., they can live only on other living organisms.

Once they are out of the body of the host, they die.

Examples: HIV virus, tapeworms, etc.

4. Facultative parasites:

These parasites are organisms that can live independently if no host is available.

Ex: Leeches, mosquitoes.

5. Hyper parasites:

These are a special type of parasites.

They are parasites that live on another parasite.

Ex: Bacteriophage viruses like tobacco mosaic virus live on bacteria like E-coli.

6. Pathogenic parasites:

These are parasites that induce severe adverse effects on the host.

They tend to release toxins, take up essential nutrients, or bring about abnormal changes in the host body.

Ex: Epstein bar virus infection in humans can lead to Hodgkin lymphoma (a type of cancer).

7. Non-pathogenic parasites:

These parasites rely on the host body for nutrition and other requirements.

However, the host body is unaffected or very minutely affected by the parasite. Ex: tapeworms.

8. Intermittent parasites:

These parasites rely on the host only at times when nutrition is required.

Types of Parasites

They are not constantly attached to the host. They visit the animals and leave often.

Ex: insects like mosquitoes, bed bugs, etc.

9. Monogentic parasites:

These are the parasites that complete their life cycle in a single host.

For example, flatworms are monogenetic flukes on fish.

The larvae are hatched in the water, and when they come in contact with the fish surfaces, they stick to them and never move.

10. Digenetic parasites:

These are parasites that complete their life cycle in two hosts: malaria, which lives in both mosquitoes and humans.

Tapeworms live in pigs and humans.

They take up different morphological forms in different animals.

The mosquito parasite exists as a cyst in mosquitoes before entering the human blood.

Then, in human blood, it converts to another form called schizont.

Parasites based on the organism class


a. Plants: A few plants also act as parasites. Ex: Sandalwood tree. 

b.Bacterial: Many bacteria act as parasites and cause potential diseases

Ex: Cholera bacteria (vibrio cholera), Tuberculosis bacteria.


Fungi are multi-cellular organisms, and some of them act as parasites.

Examples: Candida, Aspergillus.

They cause many external and internal diseases in humans and animals.

However, some fungi are used for disease control in plants.

d.Protozoans: These single-celled organisms are parasites, Ex, Entamoeba, Plasmodium

e. Insects: Mosquitoes, lice, bed bugs.

f. Worms: Leeches, Roundworms, hookworms, etc.

Frequently Asked Questions and Answers

How is parasitism different from other types of symbiosis?

Parasitism causes loss and suffering (disease) to the host. Meanwhile, symbiosis contributes to mutual benefit and promotes health.

Can intestinal parasites be transmitted sexually?

No, they can’t be transmitted as the route of elimination is different.

Can alcohol kill parasites?

Alcohol at high concentrations, above 70% or more, can be harmful to (kill) parasites, but at low doses cannot be harmful to parasites.

Can fasting kill parasites?

Fasting can boost immune cells, and these cells can kill parasites.
But, at the same time, a lack of sufficient diet can decrease protein content in the body and cause immune deficiency, further promoting parasite virulence.



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