Protista Paramecium: Habitat & Importance

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

Paramecium are members of the Kingdom Protista, and some of the first organisms a biology student encounters in the laboratory. This lesson will describe Paramecium in nature and explain why they are so popular in biological teaching and research.

What Are Paramecium?

If you've ever taken an introductory biology class, you may have encountered a laboratory exercise that involved studying Paramecium under a microscope. They are one of the most commonly used organisms in biology laboratories.

Paramecium are members of the Kingdom Protista and the genus Paramecium. When referring to the genus as a whole, we capitalize and italicize the word. When we are casually referring to a group of organisms, such as a population in a laboratory, we can call them paramecia. Paramecium are unicellular, meaning the entire organism is made up of just one single cell. All Paramecium are eukaryotic; the cell contains specialized compartments, including a defined nucleus in a membrane. The largest individuals are around 0.5 mm in length, so they're relatively big for a unicellular organism.

Paramecium Body Structure

You already know a little bit about the Paramecium body structure: paramecia are single-celled and usually smaller than 0.5 mm in total length. As eukaryotes, the cell has specialized compartments within it. These specialized compartments in the cell are called vacuoles, and each vacuole has a job to do to keep the cell functioning.

For example, when food enters the body through the mouth-like area called the gullet, it enters a food vacuole. The food vacuole functions like the digestive system in more complex organisms and breaks the food down into nutrients to be used by the cell. The food vacuoles move around the cell to deliver nutrients as needed.

Paramecium also have a contractile vacuole to control the amount of water in the cell. The contractile vacuole stores water and expels excess water from the cell by contracting (easy to remember, right?). Vacuoles and other structures are surrounded by a jelly-like substance called cytoplasm in the cell.

Where Do Paramecia Live?

Paramecia are hearty organisms found living in almost all types of water bodies. Paramecium species are found in both fresh and salt water, and some can live in moist soil or even in other organisms.

Paramecia cells are ringed with tiny, hair-like projections called cilia. The cilia sway back and forth, propelling the cell through the water. They can also help guide food particles to the gullet. Most of the time, paramecia are attached to the substrate, like rocks, pebbles, or even a plant, at the bottom of a body of water, but if they decide to move, they can use cilia and currents to find a new location.

Paramecium viewed through a microscope.

Paramecia in Teaching and Research

Paramecium are some of the most commonly studied organisms in biology, but why is this? There are couple of reasons. First, paramecia are very easy to find in nature because they are so widespread. They can easily be collected and moved to a laboratory. Once in the lab, they are easy to keep alive and happy. It doesn't take long to grow a population in the lab.

Paramecia reproduce through a process called binary fission. This means that one organism (comprised of a single cell) can split in half to form two independent organisms. This type of reproduction can easily occur in a Petri dish on a lab bench.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account