What is Parasitism?
The relationship between two species where one organism which is called the parasite lives on or within the body of the other organism which is called the host, this relationship is known as parasitism. Parasites cause some kind of harm to the body of the host. In order to increase the fitness of its own, a parasite tries to gain food or shelter in the host’s body and reduces its fitness.
Types of Parasites
On the basis of where parasites live, they have been classified into three categories-
Ectoparasites- The parasites that live upon the surface of the body of the host are known as ectoparasites. Examples of ectoparasites are fleas, ticks, etc.
Endoparasites- The parasites that live inside the body of the host are known as endoparasites. Examples of endoparasites are- roundworms, protozoa in blood, etc.
Meso Parasites- The parasites that enter the host body through an opening and embed themselves are known as meso parasites. An example of mesa-parasites is a copepod.
Parasites on the Basis of the Life Cycle
Parasites can be distinguished on the basis of their life cycles into two categories-
Obligate Parasite- The parasites which require the bodies of their host in order to survive are known as obligate parasites.
Facultative Parasite- The parasites which do not require the bodies of their hosts in order to complete their life cycle are known as facultative parasites.
Parasites on the Basis of their Strategies
Parasites are classified on the basis of their strategies into three categories-
Directly Transmitted Parasites- The parasites that reach the body of their hosts on their own are known as directly transmitted parasites. Examples are fleas and mites.
Trophically Transmitted Parasites- The parasites which are entered in the body of hosts when they eat them are known as trophically transmitted parasites. Examples are trematodes and roundworms.
Vector Transmitted Parasites- The parasites which are dependent on the intermediate host which will take them to their definitive host are known as vector transmitted parasites. Example- Protozoan that causes sleeping sickness that is transported by insect bites.
Other Types of Parasites:
Brood Parasitism- Parasitism in which young parasites are raised by the hosts is known as brood parasitism. Example- Cuckoo.
Klepto Parasitism- The parasitism in which the food of the host is stolen by the parasite is known as kleptoparasitism. Example Skuas stealing food
Sexual Parasitism- The type of parasitism in which the males are dependent on the females for survival is known as sexual parasitism. Example- anglerfish
Advantages of Having Parasites Around
Since parasites spread harm to the body of their hosts, it is believed that they are dangerous and should be eradicated. Yet, on the other hand, parasites are very useful for the ecosystem in the following ways-
Parasites control dominant species.
They allow competition and diversity.
Parasites help in the transferring of genetic material between the species.
Conclusion
Parasites are present in every biological Kingdom such as animals, plants, fungi, protozoa, bacteria, viruses, etc. Some of the parasites are roundworms, mosquitos, all viruses, and malaria-causing protozoans. Students can achieve good marks on this topic by practicing from Vedantu.
FAQs on Parasitism
1. What are some diseases spread by parasites?
Parasites are usually found in contaminated water, food or unhealthy environments. Parasites can cause harm to the body of the host in many ways. Some of the diseases spread by parasites are as follows-
Parasites are responsible for vector-borne diseases such as Malaria, Chagas Disease, etc.
Parasites are also responsible for some water-borne diseases such as amoebiasis, guinea worm, and giardiasis.
Parasites can also cause infection in the stomach such as in ascariasis.
2. How are parasitic infections spread?
Parasitic infections can be spread via three types of organisms-
Protozoa- Single-celled organisms which live and multiply inside the body. It can enter your body through drinking contaminated water.
Helminths- Multi Celled organisms that can survive in or outside the body of the host. They mostly include worms that can enter the body through contaminated soil.
Ectoparasites- Organisms that live on or feed off of the skin of the host. They can find their way to the host themselves such as fleas and mosquitoes.
3. What are some symptoms of parasitic infections?
The symptoms of parasitic infections vary according to the organisms-
A sexually transmitted infection, known as Trichomoniasis, is caused by a parasite and shows no symptoms. However, in some cases, it may cause itching, redness, and irritation in the genital area.
Some symptoms of giardiasis might include diarrhea, gas, or dehydration.
Symptoms of Cryptosporidiosis might include stomach cramps, weight loss, fever, dehydration, vomiting, etc.
Other symptoms of parasitic infections may include swollen lymph nodes, muscle aches, or severe body pains.
4. What are the differences between a parasite and a pathogen?
Parasite | Pathogen |
A parasite can live in or outside the body of its host. | Pathogens can cause sickness or diseases to their hosts. |
Protozoa, Helminths, and Ectoparasites are three main types of parasites. | Bacteria, Fungi, Viruses, Protozoa, Rickettsia, and Helminth are six main types of pathogens. |
All parasites are not harmful and do not spread disease to the body of the host. | All pathogens are harmful to the host body and can cause harmful diseases. |
Parasites are macroscopic. | They can either be microscopic or macroscopic. |
To learn about the differences between Parasites and Pathogen, students can visit Vedantu’s study material where the difference between them is explained in detail.
5. How can Parasitic infections be diagnosed?
There are many ways parasitic infections can be diagnosed. Some of these are endoscopy or colonoscopy, fecal tests, X-Rays, Magnetic Resonance Imaging (MRIs), CT Scans, Computerized axial tomography (CAT), and so on. Doctors can also diagnose the infections by taking blood samples, urine samples, sputum samples, etc. Doctors can also take samples of the tissue which might contain the parasite, such procedures are known as a biopsy.
