Parasitism - Definition, types and examples

Parasitism is one of the most widespread life strategies in the Animal Kingdom, being at least 20% of the parasitic animal species of other organisms.

There are taxa only composed of parasitic beings, such as viruses and acanthcephals (parasitic worms).These types of organisms live at the expense of other living beings, either during their entire life or for a short period.

In this article of Animals and Pets Online we will learn the definition of parasitism, the different types that exist, we will understand what advantages and disadvantages this style has of life and we will know some examples.

What is parasitism?

Parasitism is a type of symbiosis in which one of the organisms involved (host) is harmed, that is, it does not obtain any benefit and also suffers damage derived from the relationship.On the other hand, the parasite find in this relationship its survival mode.This type of relationship is maintained until one of the two individuals (parasite or host) dies.

Within this relationship, each member belongs to a different species.parasito needs to live in the host to get food, often genetic material for the creation of their own proteins and, in addition, finds in the host their habitat, without which they could not live.

For everything this, parasites are organisms that need a close and continuous relationship with a host (of another species), which provides food, digestive enzymes or materials and stimulates them to develop or reproduce.

Types of parasitism

There are several ways to classify parasites, then we show you the best known or used:

Taxonomic classification: taxonomically, parasites are classified as phytoparasites when they parasitize plants and zooparasites when they infect animals.In parasitology, a science that studies parasites, only zooparasites are treated.

Classification according to the level of dependence the parasite has on the host:

• Optional parasite: are those species of parasites that are capable of living through another form of life in addition to the parasitic.
• Mandatory parasite: they are those that cannot live outside the host, they depend totally on it for any stage of development.
• Accidental parasite: they are the parasites that, by mistake, end up inside an animal which is not their usual host and, despite this, gets Survive.
• Erratic parasite: parasites that live in e The interior of the animals usually do so in a specific organ or tissue.A parasite that is in an organ that is not normal is known as an erratic parasite.

Classification according to the location of the parasite within of the host:

• Endoparasite: are the parasites that need to live inside the host, such as the heart, lungs, liver or digestive tract.
• Ectoparasite: they live on the host, never inside.For example on the skin or hair.

Classification according to the period of time that the parasite keeps the host parasitized:

• Temporary parasites: the parasitic phase is temporary and only occurs on the surface of the animal (host), never inside.The parasite is fed on the host, its skin or blood, for example.
• Periodic parasite: the parasite needs to pass one of the stages of his life (egg, larva, juvenile or adult) inside the host, then he will live freely.
• Permanent parasite: the parasite must spend his entire life inside or outside the guest if he wants to survive.

Advantages of living as a parasite

In the beginning, the animals we know today as parasites had a free lifestyle in the past.The fact that at a given moment in evolution these animals acquired a parasitic lifestyle, it suggests that they should get some kind of benefit.

The first advantage that parasites find is that of habitat.Animals have mechanisms to keep homeostasis inside their body, which gives the parasite the possibility of living in a medium that barely has fluctuations.

On the other hand, they have an easy way of distributing their offspring over large areas quickly.For example, if the parasite releases eggs to through the feces of his host, it is certain that his offspring will develop in other places.For a parasite the food is always close and available, because it feeds on the host itself or part of the food that it eats.

Disadvantages of living as a parasite

Not all are advantages for parasitic life animals.The fact of living inside a body makes the parasitic congenres far away, both in space and time, since they will live in other guests, Therefore, strategies for sexual reproduction must be found in order to combine genetic material.

As a rule, guests do not want to be parasitized, so they will be hostile to parasites and try to get rid of them.at all costs, for example, through grooming.In addition, the guest may die, so the habitat is not forever.

Examples of parasitisms

In this section we show you some of the most known and common parasitic relationships, many of them, are also zoonoses.

• Coccidiosis is a disease caused by a group of protist parasites belonging to the subclass Coccidiasina.Coccidia are obligate intracellular parasites, so they need a host to live, they must also be found not only inside the animal, but inside their cells.
• Echinocosis or hydatidosis is another serious disease caused by the relationship that occurs between a parasite of the Cestoda class and a mammal, usually cattle, pets or the human being itself.Cestodes are endoparasites of the digestive tract like tapeworms.Their larvae can travel through the blood to other organs such as the liver, producing hydatid cysts.
• Fleas and lice are other good examples of parasitism.In this case, parasites live on the animal and not inside it.

If you want to read more articles similar to Parasitism-Definition, types and examples , we recommend that you enter our Curiosities section of the animal world.

Bibliography

• Palacios, JT, Chiaretta, A.,&Lovera, H.(2006).Parasitism: An Interspecific Association.Argentina: National University of Rio Cuarto.
• Posada, JOA (2014).Description of the most common intestinal parasites in canines taken to the Lasallian Veterinary Clinic Brother Octavio Martinez Lopez.Journal of Agriculture and Animal Sciences, 2 (1).
• Taylor, MA,&Catchpole, J.(1994).Coccidiosis of domestic ruminants.Applied Parasitology, 35 (2), 73-86.