We often hear about diseases caused by parasites. But have you ever wondered what is a parasite?
We've all studied about the ecological relationships and how living beings are related. When we talk about parasites, we are talking about a well-known ecological relationship: the parasitism.
In this relationship, which is established between organisms of different species (interspecific relationship), one of the individuals involved installs itself on the other's body to remove food. The organism that removes the food is the parasite, while what is being parasitized is the host.
In parasitism, only one of the organisms involved is benefited and the other is harmed. This type of relationship does not result in the host's death, as the longer it lives, the longer the parasite will have to feed. For this, it is essential that the parasite does not remove many nutrients from the host's body, as the host would be very debilitated and would end up dying, which would also lead to death for the other organism.
The parasite can live both outside and inside the host's body. If it lives outside it is known as an ectoparasite, but if it is inside an organism it is an endoparasite. You lice and ticks, for example, are examples of ectoparasites, as they live on the surface of the body of animals. As for nematodes, such as worms, live in the intestine of the host and are, therefore, endoparasites.
Do not stop now... There's more after the advertising ;)
It is important to highlight that it is not only animals that have parasites, all living organisms can be parasitized. Even a bacterium can be the target of this type of relationship, as is the case of virus bacteriophages that reproduce within these organisms.
There is also a case of parasitism that is known by many biologists as parasitism. In this relationship, it is observed the host death, a fact that, in general, does not occur in cases of parasitism. As a classic example of parasitoidism, we can mention wasps, which lay their eggs inside some arthropods. After hatching, the larvae feed on the host still alive. After some time, they kill the host and emerge from its interior.
Important: Parasitology is the science that studies parasites, their hosts and the relationship between these organisms.
By Ma. Vanessa dos Santos
Would you like to reference this text in a school or academic work? Look:
SANTOS, Vanessa Sardinha dos. "What is a parasite?"; Brazil School. Available in: https://brasilescola.uol.com.br/o-que-e/biologia/o-que-e-parasita.htm. Accessed on June 27, 2021.
