Content
- what is parasitism
- Types of parasitism
- Advantages of living as a parasite
- Disadvantages of living as a parasite
- examples of parasitism
Parasitism is one of the most widespread life strategies in the Animal Kingdom, with at least 20% of animal species being parasites of other organisms.
There are taxa composed only of parasitic beings, such as viruses and acanthocephali (parasitic worms). These types of organisms live at the expense of other living beings, either for their entire lifetime or for a short period of time.
In this article by PeritoAnimal we will learn the meaning of parasitism, the different types that exist, as well as understand the advantages and disadvantages of this lifestyle and also some examples.
what is parasitism
Parasitism is a type of symbiosis in which one of the organisms involved (host) is harmed, that is, don't get any benefit and it also suffers damage from the relationship. On the other hand, the parasite finds its survival mode in this relationship. This type of relationship continues until one of the two individuals (parasite or host) dies.
Within this relationship, each member belongs to a different species. The parasite must live in the host to obtain food, often genetic material to create its own proteins, and it also finds its habitat in the host, without which it could not live.
For all these reasons, parasites are organisms that need a close and continuous relationship with a host (of another species), which provides it with food, digestive enzymes or materials and encourages it to develop or reproduce.
Types of parasitism
There are several ways to classify the parasites, below we show the most 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: those parasitic species that are capable of living through a form of life other than the parasitic one.
- mandatory parasite: are those that cannot live outside the host, as they are totally dependent on it for any stage of development.
- accidental parasites: parasites that mistakenly end up inside an animal that is not its usual host and still manages to survive.
- erratic parasite: Parasites that live inside animals usually do so in a specific organ or tissue. A parasite that finds itself in an organ that is not its usual host is known as an erratic parasite.
Classification according to the location of the parasite within the host
- endoparasite: These are the parasites that need to live inside the host, such as the heart, lungs, liver or digestive tract.
- ectoparasite: they live in the host, but never inside it. For example, on skin or hair.
Classification according to the length of time the parasite keeps the host parasitized:
- Temporary parasites: the parasitic phase is temporary and occurs only on the surface of the animal (host), never inside. The parasite feeds on the host, its skin or its blood, for example.
- Periodic parasite: the parasite needs to pass one of its life stages (egg, larva, juvenile or adult) inside the host, after which it will live freely.
- Permanent parasite: the parasite must spend its entire life inside or outside the host if it is 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 certain point in evolution these animals acquired a parasitic lifestyle makes us think that they should receive some kind of benefit.
The first advantage that parasites find is that of habitat. Animals have mechanisms to maintain the homeostasis inside its body, which gives the parasite the possibility to live in an environment that has virtually no fluctuations.
On the other hand, they have an easy way to distribute your offspring over large areas quickly. For example, if the parasite releases eggs through its host's feces, it ensures that its offspring will develop elsewhere. For a parasite, the food it is always close and available, as it feeds on the host or part of the food he eats.
Disadvantages of living as a parasite
Not everything is an advantage for parasitic animals. The fact of living inside a body makes the parasitic congeners are far away, both in space and time, as they will live on other hosts, therefore sexual reproduction strategies must be found to match the genetic material.
As a general rule, guests do not want to be parasitized, so they will be hostile towards parasites and will try to get rid of them at all costs, for example through grooming. Also, the host can die, so the habitat doesn't last forever.
examples of parasitism
In this section we show some of the best known and most common parasitic relationships, many of which are also zoonoses.
- THE coccidiosis is a disease produced by a group of prosthetic parasites belonging to the subclass Coccidiasina. Coccidia are forced intracellular parasites, so they need a host to live, and they must be not only inside the animal, but inside its cells.
- THE echinococcosis or hydatid disease it is another serious disease caused by the relationship between a parasite of the Cestoda class and a mammal, usually cattle, pets or the human being. Cestoids 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, the parasites live on the animal and not inside it.
If you want to read more articles similar to Parasitism - what is it, types and examples, we recommend that you enter our Curiosities section of the animal world.