The article tells about what parasitism is, what are its forms. In addition, the issue of similarities and differences between this phenomenon and predation is considered.
Life
Life on our planet exists for about 4 billion years. And during this time, a huge number of biological species managed to appear, develop, and disappear on it. And this process is likely to continue. Despite this, any form of life, even the simplest and smallest, is very amazing from a scientific point of view. However, as well as some forms of existence of species. One of them is parasitism. This phenomenon is quite common. So what is parasitism, what forms does it take, what are its features? We will look into this further.
Definition
Parasitism is one of the main types of coexistence of organisms. Unlike the others, it is characterized by the fact that two or more living beings that do not have a genetic connection between themselves and in general are heterogeneous, live together for a long time, but at the same time remainantagonists. This is a kind of relationship between different biological species. One of them is a parasite. It uses another (host) as a source of nutrition. At the same time, it imposes on it, in whole or in part, the relationship with the environment. Now we know what parasitism is.
If we talk about the groups in which this type of coexistence occurs, 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 are highly dependent on obtaining the biological resources necessary for these actions. If we talk about the degree of parasitism, then the longer the organism exists at the expense of the host, the less it eventually causes harm to the latter. The victim always adapts. What is parasitism, we now know. But let's take a closer look at its main varieties.
Shapes
If we talk about what forms of this phenomenon exist, they are also very diverse. Parasites are both animal and vegetable. They differ in that they use different sources to obtain resources: representatives of fauna and flora, respectively. Plants according to the official classification are 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 former, the creature resides outside its master and is somehow connected to it.skin or other coverings. The most striking example of this is ticks or fleas. Both need people or animals to live. They hide either in the hairline or bite into the skin.
In the case of endoparasitism, the organism lives inside a being that provides it with all the necessary biological resources. These forms include protozoa, parasitic worms, and others. Oddly enough, but it is the second species - life inside the host - that is much more common than ectoparasitism. According to biologists, this is due to the fact that it is easier and easier to live inside, since it is very difficult to detect a pest. You won’t accidentally crush it, you won’t brush it away like the same tick or flea.
As a rule, parasites that live inside the host use passive propagation mechanisms. For example, the 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 host due to a 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 a reason. Their distinguishing features are not in size or distribution methods. The thing is that they parasitize, being themselves such. Such a creature lives off the pest that resides in the animal. And it is called a parasite of the second kind. In very rare casesyou can meet similar "impudent" of the third and fourth order!
Predation and parasitism
The classification distinction between pure predation and parasitism is quite debatable. And it often causes confusion. Sometimes this definition is understood as any eating of one organism by another, and without killing. Simply put, it is the relationship between parasite and host. But we will still try to figure it out.
As with classic animal predation, the parasite damages the external or internal structure of the host organism. Only the goals of the uninvited invasion differ. If we consider the similarities and differences between predation and parasitism, then the pest, as a rule, lives on one host throughout its life. He has no interest in his death. True, this is not always the case. Some types of parasites, although they live inside, but their ultimate goal is to devour the victim. For example, this is what the larvae of some Diptera do.
Science also knows some animals that can combine a parasitic lifestyle with a predatory one. Such qualities are possessed by bugs of the Predator family. They can feed on both other insects and the blood of humans or other warm-blooded animals.
What are the similarities between predation and parasitism?
For all their differences, of course, there is a similarity. Both parasites and predators live at the expense of others. It's just that the latter do it, periodically going hunting. Solions, tigers, panthers, and so on. Others, due to their small size, are forced to eat carefully, emphasizing ste alth.
