What is parasitism?

We explain what parasitism is and some examples of parasitism. In addition, the types that exist and what is social parasitism.

1. What is parasitism?

Parasitism is a biological relationship between two organisms of different species , one called a host (which receives or receives) and another called a parasite (which depends on the host to obtain some benefit). This process, in which one organism is used to cover the basic needs of another, allows to expand the survival capacity of some species.

Parasitism can happen throughout all phases of an organism’s life or only in specific periods. It can also happen that, as the parasite is still an organism, it hosts another specimen. These cases, in which the parasite hosts another parasite, are called hyperparasitism.

2. Examples of parasitism

Among the most common examples of parasitism are:

• Fungi . They usually stay in the feet, nails or skin of animals and feed on keratin, an abundant protein in the epidermis.
• The mites They usually lodge in the skin and feed on wastes such as kerantinocytes ( dead cells ) or secretions.
• Mistletoes They usually stay in several tree species in areas of Europe, America and Africa.
• Termites They usually stay in trees and woods used for housing construction. They have a great capacity for destruction.
• Bacteria and viruses . They are usually found in water and on earth, so they enter the body through food and stay in the digestive system of animals.
• Amoebas They usually stay in the intestines of animals . They feed on the host, so they can cause malnutrition and serious diseases.
• Earthworms They usually stay in various parts of the host’s organism and can take away their nutrients.

3. Types of parasitism

Parasitism is classified into two large groups according to the type of parasite:

• The ectoparasites. They are parasites that are outside the host’s organism and take advantage of what they find in the outermost layer of the dermis and even consume a little of their blood. For example, fleas and ticks.
• Endoparasites They are the parasites that are inside the host. Depending on the species of the parasite, some can cause mild damage and others, very serious. For example, worms that live in the intestines.

4. Social parasitism

Social parasitism refers to the type of association that some animal species make to obtain some benefit , but that does not directly impact their organism or biology but benefits it in their social development. For example, some birds lay their eggs in nests of other bird species, for the latter to raise.

Social parasitism within a community of people exceeds the strictly biological point of view mentioned above and refers to a derogatory type association, in which the parasite undermines the ethics and morality that prevails in the host society (i.e. , it does not obtain directly biological benefits). For example, in some regions, individuals living with and from their parents are considered “parasites” up to advanced ages of adulthood, obtaining as a benefit a life of comfort and minor concerns.