Learn about the kinds of parasites out there. One of the most interesting relationships in biology is parasitism. In this kind of interaction, one member can stand alone while the other leeches off what it needs to live from the independent member. Parasites are usually smaller than the host. The classification of the kinds of parasites is made in accordance with the way they interact with host, and also the progression from early life stages to adulthood.
When the parasite lives on the surface of the host and causes discomfort such as itching, the interaction is known as ectoparasitism. Unlike the other kinds of parasites, ectoparasites can thrive even when exposed to the external environment with little or no protection. A good example is Pediculus humanus capitis, also known as head lice. Unwashed or infrequently washed scalp skin is the ideal environment for head lice. They live on the scalp and can transfer from one host to another by crawling. Using another person’s comb when that other person is infected can lead to transfer of parasites. Lice cannot fly but they can crawl from one host to another.
These are the most common among the different kinds of parasites. Endoparasites thrive inside a closed environment, which is the host’s body. Examples of these include parasitic worms in humans and animals. Endoparasites are further classified into intercellular and intracellular kinds of parasites. Intercellular parasites thrive in spaces and do not affect individual cells, while the opposite is true for intracellular parasites. Intracellular types include bacteria and viruses that destroy cells and invade the body with the help of a vecto. One good example is how viruses are transferred between humans by mosquitoes or flies.
The life cycle of epiparasites is unique compared to other kinds of parasites because this type preys on other parasites. This is a good example of hyperparasitism. In this case, a parasite already inhabiting the host may in turn be inhabited by another smaller parasite. For example, fleas are inhabiting the body of a canine animal, and the fleas themselves harbour protozoans in their gut.
Some kinds of parasites deserve to be in their own class because of the way they behave. Social parasites are opportunists that take advantage of unsuspecting hosts to get what they need. One example is kleptoparasitic critters that steal food from the stores of brood organisms such as ants. Some birds like the cowbird may also be social parasites because they deposit eggs on nests of other birds so that the host bird can take care of their young in their stead.
When the host is related taxonomically to the parasite, this may be considered adelphoparasitism. Members of the same genera or families can show this kind of parasitic relationship.
Among different kinds of parasites, parasitoid infestation may be the most detrimental to the host. Like a true parasite, parasitoids spend important phases of its life cycle depending on the host. However, once the parasitic organism has passed these phases, the host may be subjected to injury. In some cases, the parasitoid can render the host sterile.