The article talks about what is parasitism, what are its forms. In addition, the issue of similarities and differences of this phenomenon with predation is considered.
A life
Life on our planet has been around for 4 billion years. And during this time, a huge number of biological species managed to appear, develop, disappear on it. And, probably, this process will continue further. Despite this, any form of life, even the simplest and smallest, is very surprising from a scientific point of view. However, like some forms of the existence of species. One of them is parasitism. This phenomenon is quite common. So what is parasitism, what forms does it have, what are its features? In this we will understand further.
Definition
Parasitism is one of the main types of coexistence of organisms. Unlike the others, it is characteristic of him that two or more living creatures that do not have a genetic connection between themselves and are generally heterogeneous, live together for a long time, but at the same time remain antagonists. This is a type of relationship between different species. One of them is a parasite. He uses the other (the host) as a power source. At the same time, he lays on him in whole or in part the relationship with the environment. Now we know what parasitism is.
If we talk about in which groups this kind of coexistence occurs, then they are very diverse: animals, protozoa, fungi, bacteria. As a rule, the physiological actions of the parasite are often subordinate to the host. And its life cycle and reproduction strongly depend on obtaining the biological resources necessary for these actions. If we talk about the degree of parasitism, then the longer the body exists at the expense of the owner, the less harm it ultimately causes to the latter. The victim always adjusts. What is parasitism, we now know. But we will analyze in more detail its main varieties.
Forms
If we talk about what forms of this phenomenon exist, then they are also very diverse. Parasites are both animal and plant. They differ in that they use different sources to obtain resources: representatives of fauna and flora, respectively. According to the official classification, plants are commonly called phytoparasites. Most often, these are small fungi, a little less often - bacteria. Now consider the forms of parasitism. There are only two of them.
There are so-called ectoparasitism and endoparasitism. In the case of the first, the creature lives outside its master and is somehow related to its skin or other integuments. The most striking example is ticks or fleas. Both need people or animals for life. They hide either in the hairline or bite into the skin.
In the case of endoparasitism, the body lives inside the creature, which provides it with all the necessary biological resources. Such forms include protozoa, parasitic worms and others. Oddly enough, but it is the second species - life inside the host - that occurs much more often than ectoparasitism. According to biologists, this is due to the fact that living inside is easier and easier, since it is very difficult to detect a pest. You will not accidentally crush it, you will not brush it away like the same tick or flea.
As a rule, parasites that live inside the host use passive propagation mechanisms. For example, larvae are laid in the grass, then the animal eats them together with the vegetation, and already inside it they hatch. And ectoparasites use active methods to spread. There are also necrotrophic parasites. They differ in that they cause the death of their carrier due to lack of nutrients. Or he dies due to toxic substances released by pests in the course of their life.
Superparasites
Superparasites were named so for good reason. Their distinguishing features are not in size or distribution methods. The thing is that they parasitize, being themselves so. Such a creature lives off of a pest in the animal. And it is called a parasite of the second kind. In very rare cases, you can find such "impudent" third and fourth order!
Predation and parasitism
The classification distinction between pure predation and parasitism is quite controversial. And often causes confusion. Sometimes by this definition is meant any eating of one organism by another, without killing. Simply put, this is the ratio of the parasite to the host. But we still try to figure it out.
As in the case of classical animal predation, the parasite damages the external or internal structure of the host organism. Only the objectives of the uninvited invasion differ. If we consider the similarities and differences between predation and parasitism, then the pest throughout his life, as a rule, lives on one host. He is not interested in his death. True, this is not always the case. Some species of parasites, although they live inside, but their ultimate goal is to devour the victim. For example, the larvae of some dipteran insects do this.
Also, science knows some animals that can combine a parasitic lifestyle with a predatory one. The bugs of the Predator family possess such qualities. They can feed on other insects, as well as on the blood of humans or other warm-blooded animals.
What is the similarity between predation and parasitism?
For all its differences, there are, of course, similarities. Both parasites and predators live at the expense of others. Just the latter do it, periodically going hunting. So do lions, tigers, panthers and so on. Others, due to their small size, are forced to eat carefully, focusing on secrecy.