Parasite Definition

Introduction

A parasite is an organism that lives within or on the body of another species, usually at the expense of the host species. A parasite is a plant or an animal that lives on, with, or inside a larger species to extract nutrients from the larger species. In some cases, the parasite can cause harm to the host, while in other cases, it is completely harmless to the host. Generally speaking, parasites can be divided into three categories, namely ectoparasites, endoparasites, and mesoparasites.

Parasites

Ectoparasites are parasites that can survive outside of the host and cause itching and rashes in the area where they are present. Endocrine parasites are parasites that live inside the body of their host, usually in the bloodstreams of the host or in the muscles, digestive system, and other organs. A type of parasite known as a mesoparasite is one that enters the host through an opening in the body and embeds itself partially within the host.

Parasitic infections can be brought on by a wide range of organisms, ranging from protozoa and helminths to arthropods. For example, giardia is a parasitic infection of the intestine that is caused by the giardia parasite.

The word “parasite” is derived from the Greek word meaning “one who eats at the table of others,” and it is believed to have originated around 5900 BC.

Host-cell parasites are an incredibly diverse group of organisms that live within the cells of their hosts. They are smaller in size than their host organism and reproduce more quickly as a result of the greater amount of damage they cause to the host. They are provided with a variety of benefits by the host, including food and shelter. Their size ranges from microscopic single-celled organisms to worms that can grow to be 20-30 metres in length.

Examples include tapeworms, which are flat, segmented worms that live in the intestines of animals, where they feed on the nutrients that the host provides.

Parasitic Symbiosis

Symbiosis is a term that refers to a long period of interaction between two different species of plants or animals. Mutualism is a term used to describe situations in which both species benefit from a particular interaction. Because the larger organism is the one on which the smaller organism is dependent in a symbiotic relationship, the larger organism is referred to as the host. The smaller organism is referred to as a symbiont because it lives within the larger organism.

Partial symbiotic relationships or long-term relationships between any two species, whether plants or animals are referred to as parasitism or symbiosis. In this case, the parasite receives benefits from the host, which causes the host to suffer harm without killing it.

Parasites such as leeches, fleas, ticks, and lice are examples of parasites that do not normally cause disease in humans or animals. Their only method of feeding is to suck blood from their host without causing harm to the host.

The Different Types of Parasitism

The following are the different types of parasites based on their size, characteristics, and relationship with the host:

1. Endoparasites

2. Ectoparasites

3. Mesoparasites

• Endoparasites are parasites that live within the body of their host. Examples include Plasmodium falciparum, a parasite that causes malaria in humans, and other diseases.

• Ectoparasites are parasites that live outside the body of their host. For example, bedbugs are a parasite that can cause skin irritation and itching.

• Mesoparasites are parasites that enter the body of a host through a small opening and embed themselves only partially. It is also possible that these parasites will transmit pathogens that cause disease to other species of animals.

A typical parasite’s life cycle includes several developmental stages that are common to all parasites. When a parasite lives and moves through one or more hosts, it undergoes two or more changes in its body structure, which can be quite dramatic. The fact that the number of parasites outnumbers the number of free-living organisms indicates that the parasitic lifestyle has proven to be a successful one over time.

Parasitic Symbiosis Examples

Listed below are some illustrations of parasitic symbiosis:

Fasciola hepatica

This is also referred to as the Liver Fluke. Initially, it attaches itself to the liver, from where it makes its way to the tissue and bile.

Plasmodium

Plasmodium is a parasite that is picked up by mosquitoes and transmitted to different people, resulting in Malaria. There are several different species of Plasmodium that cause Malaria.

Hirudinea

To complete their life cycle, leeches are typically reliant on a variety of animals. Freshwater fish, slugs, snails, mice, bears, and other small animals are among the animals on which leeches rely.

Taenia solium

It can survive in the human gastrointestinal tract for years at a time. It seeps into undercooked pork and spreads. More than three metres in length, these are enormous!

Conclusion

A parasite is an organism that lives on or in a host organism and obtains its food either from or at the expense of the host organism in which it lives. When it comes to parasites that can cause disease in humans, there are three main categories to consider: protozoa, helminths, and ectoparasites.