Difference Between Endoparasites and Ectoparasites

The key difference between endoparasites and ectoparasites is that the endoparasites are parasitic organisms that live inside the host organism while ectoparasites are parasitic organisms that live outside of the host, mainly on the skin.

A parasite is an organism that lives on or in another organism known as the host. The parasite obtains nutrients from the host. Parasitism is the relationship that exists between host and parasite. Parasites always depend on a host, and they cannot live without the host. This relationship is harmful to the host, but it is beneficial to the parasite. This may cause severe diseases to hosts. Sometimes parasites may even kill the host. Many parasites have complex life cycles that need several hosts for growth and reproduction. For that, they have acquired many unique adaptations that can alter the behavior of the host and make them more vulnerable to their predators. This process enables the transmission of parasite stages from one host to another. Depending on the living environment of parasites, they can be classified as endoparasites and ectoparasites.

CONTENTS

1. Overview and Key Difference
2. What are Endoparasites  
3. What are Ectoparasites
4. Similarities Between Endoparasites and Ectoparasites
5. Side by Side Comparison – Endoparasites vs Ectoparasites in Tabular Form
6. Summary

What are Endoparasites?

Endoparasites are parasites that live inside the body of the host. We also call them internal parasites. They occur in many different phyla of animals and protists. These parasites can live in either intracellular or extracellular environments within a host. Intracellular parasites live inside the cell bodies (eg: malaria parasite in human red blood cells). Extracellular parasites may live in body tissues (eg: Trichinella lives inside muscle tissue) or in body fluids (e.g: Schistosoma lives in blood plasma) or in the alimentary canal (eg: Taenia and Ascaris). Normally, intracellular parasites such as protozoa, bacteria, or viruses need a third organism, which is generally called a carrier or vector.

Endoparasites are transmitted mainly by the fecal-oral route through contaminated foods. As a result, many kinds of diseases such as diarrhea, weight loss, anemia, poor production, poor reproduction, etc occur in animals.

What are Ectoparasites?

Ectoparasites are parasites that live on the body surface of the host organism. They are also known as external parasites. These parasites can be often found in both plants and animals. Ectoparasites either suck blood (animal parasites) or juices (plant parasites) or feed on living tissue. Most ectoparasites lack wings. Furthermore, they are less harmful compared to endoparasites. But, they cause several conditions such as anemia, hypersensitivity, anaphylaxis, dermatitis, skin necrosis, irritability, low weight gains, focal hemorrhages, blockage of orifices, exsanguination, secondary infection, etc.

Moreover, ectoparasites also work as vectors for some pathogens. Some of the most common examples of human ectoparasites are lice, rat flea, ticks, and itch mite.

What are the Similarities Between Endoparasites and Ectoparasites?

• Both endoparasites and ectoparasites maintain parasitism between host and parasite.
• Also, both parasites benefit at the expenses of the host.
• Similarly, both cause harm to their host organisms.
• Furthermore, both are heterotrophs.

What is the Difference Between Endoparasites and Ectoparasites?

Endoparasites live within or inside the body of their hosts while ectoparasites live on the body surface of their hosts. Hence, this is the key difference between endoparasites and ectoparasites. Generally, endoparasites are extremely specialized and have many adaptations than ectoparasites. Thus, this is also a significant difference between endoparasites and ectoparasites. Furthermore, endoparasites normally cause severe damages to their hosts than ectoparasites do.

Moreover, a further difference between endoparasites and ectoparasites is that the respiration of endoparasites is anaerobic while the respiration of ectoparasites is aerobic. Also, an additional difference between endoparasites and ectoparasites is that the endoparasites are holoparasites while ectoparasites can be either hemiparasites or holoparasites. Worms such as roundworms, tapeworms, and trematodes and protozoans such as Plasmodium and Amoeba are endoparasites while mosquito, leech, mite, flea, tick, and louse are ectoparasites.

The below info-graphic on the difference between endoparasites and ectoparasites list the differences comparatively.

Summary – Endoparasites vs Ectoparasites

A parasite is an organism that lives on or inside another living organism (host) in order to obtain nutrient at the other’s expenses. Endoparasites and ectoparasites are two types of parasitic organisms. Endoparasites live inside the host organism while ectoparasites live on the external surface of the host organism. Compared to endoparasites, ectoparasites are less harmful. Furthermore, many ectoparasites do not possess wings while endoparasites do not possess a digestive tract. Thus, this is a summary of the difference between endoparasites and ectoparasites.

Reference:

1. “Endoparasite.” NeuroImage, Academic Press, Available here.
2. “Ectoparasite.” NeuroImage, Academic Press, Available here.

Image Courtesy:

1. “Ascaris Larva (hatched on Slide)” By SuSanA Secretariat (CC BY 2.0) via Flickr
2. “Soft tick” By dr_relling (CC BY 2.0) via Flickr