Animals are parasites. Types of parasitism

Some of the animals are born and die, they live in the organisms of other fauna. The former use the second as power sources. Animals-parasites can be found on the body of another animal, and feed on its blood. For example, fleas and lice live on the owner's skin (the so-called organism, through which parasites exist). Some animal parasites can provide themselves with food in the intestines, blood vessels, other organs, causing great harm to their owners. Death may not cause this, but it leads to a general and global weakening of the body. They can also cause diseases transmitted from some fauna-to-human species.

Parasitism

The very word "parasite" has Greek roots and is literally translated as a "parasite". Large and small, "spongers" feed on lymph and blood, tissues and digested food, permanently or temporarily use other organisms as their habitat. Parasitism is one of the ways of co-existence of different species of animals. It can be internal, external and nested.

Internal

Such animal parasites (their names are counted in hundreds) penetrate into the internal organs of various animals, live there, reproduce, give birth to a myriad of offspring, causing various poisonings by the products of their vital activity, and also certain types of diseases. A person, as a rule, can catch them by eating animal meat that has not undergone sufficient heat treatment.

Protozoa

These animal parasites are so small that they can be confused with bacteria. On a structure are unicellular organisms. They may or may not have a shell, reproduce sexually or asexually, be static or move around. As a rule, they live on mucous membranes, in blood, glands. Of especially dangerous for humans, we can distinguish the causative agent of toxoplasmosis Toxoplasma gondii and the causative agent leishmaniasis - Leishmania donovani. These parasites of animals and humans are usually transmitted with food.

Helminths

The dimensions of the parasitic worms are different and range in length from a few millimeters to several meters. Can cause helminthiases. They are divided into three groups: trematodes, nematodes and cestodes.

Trematodes

Attached with suction cups and have an elongated body without segments, which resembles a leaf. For example, the hepatic fluke, which lives in the bile duct of the sheep, but can also be transmitted to humans. It reaches a centimeter in width, and in length - up to three.

Cestodes

These animal parasites are called "shadows", or tapeworms. They can parasitize in the adult stage in the intestines of both humans and animals. And in the larval - are in some organs of fish, insects, mammals. They have a flat segmented body, of various shapes. They feed diffusely, with the help of osmosis, since they are devoid of digestive organs. For example, ekinokokk can parasitize in the intestines of dogs, and the chain-tail (sometimes its length reaches five meters) - in the adult stage in the intestines of a person. The larval stage of the chainworm passes in the muscles of the pig, and, consuming such meat without sufficient heat treatment, people can also become infected.

Nematodes

These roundworms (for example, Trichinella spiralis) have a length of up to three millimeters. Adult forms parasitize in the intestines of animals and humans, larvae can be found in the muscles. When consuming pork, infected with larvae, a person, as a rule, also becomes infected with nematodes.

Arthropod animals parasites

Examples: mites, lice, fleas and mosquitoes. Of ticks, which are intermediate hosts and carriers of a variety of pathogens - a whole family of ixodids (Ixodidae). And the family Sarcoptidae also includes a variety of mites that cause scabies in humans. Parasites penetrate into the intradermal passages in order to lay eggs, or live on the surface of the skin. They refer to external parasites.

Mosquitoes

They are also external parasitic animals. Examples of their "nahlebnicheskoy" activities - food with blood. On the human body or animals, they do not live, but parasitize, using as food the blood (ectoparasitism). It is interesting that the individuals of the mosquito of both sexes, as a rule, feed on nectar and plant juice. However, in many species (in Russia there are more than one hundred), there are devices of the mouth to pierce the skin of the victim. The female receives nutrients from the blood and acquires the ability to lay more eggs. And there are both food options: both blood and nectar. But from the blood, the female receives proteins as building materials for her eggs. Males use only nectar as food, refraining from parasitism. It is proved by science that some types of mosquitoes can use the blood of birds, reptiles and even fish as food!

Leeches

These relatives of the earthworm also prefer blood as a meal. Sucking it, they parasitize at the expense of other organisms. Leeches detect the victim by body temperature or by smell. Then they suck in, biting the skin with three jaws. Their saliva is so adapted by nature that it gives an anesthetic effect and prevents blood clotting.

Lamprey

They are freeloaders of fish. With his mouth, the lamprey sucked into the body of the fish, ripping off the skin. So she has the ability to suck blood and other fluids from the wound. When the process of saturation occurs, the lamprey falls off the wound and sinks to the bottom until it gets hungry again.

What animal parasites still exist in nature? To them can be attributed to the isopod crustaceans. They bite, as a rule, the skin or shell of sea inhabitants and feed in this way, "riding" on their master.

Nesting parasitism

Strangely enough, birds are also animal parasites. The names of these flying "spongers" number about eighty species and five families. The most famous representative is the cuckoo. She puts her eggs in someone else's nest, this way causing other species of birds (for example, woodpeckers) to grow cuckoos. A cuckoo, hatching, throws the eggs of a woodpecker from the nest, eliminating competitors.

Some fish and insects also engage in similar nesting parasitism, using other animals to grow their offspring.