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How do Paramecia Move?

Mary McMahon
Mary McMahon
Mary McMahon
Mary McMahon

Paramecia move with the assistance of small hairs called cilia that project from all sides of their bodies. The single-celled organisms use these hairs like oars, beating them against the water to move around in pursuit of food and to avoid predators. The movements are sometimes quite interesting to watch, as they are incredibly fast, considering their size. Almost any sample of still water will contain some paramecia. They are just visible with a magnifying glass, and sometimes with the naked eye, but can be seen in some detail with a microscope at around 100 X magnification.

Paramecium Movement

Three paramecia.
Three paramecia.

The way paramecia move is quite straightforward; usually, they will travel in a straight line until they bump into something and navigate around it. They may, however, change course to reach food, and it is believed that the creatures may have chemical sensors to alert them to potential sources of nutrition. Watching one move around large obstacles can remind people of navigating into small parking spaces, as it moves forward, backs up, turn, moves forward, and so forth until it in the clear again.

Paramecia.
Paramecia.

The cilia on a paramecium move in two directions. The creatures move forwards by beating their cilia at a backward angle, to thrust themselves through the water. To back up, they beat forwards. They also spin as they swim through the water, allowing them to collect food, which is pushed by the cilia into the mouth. A paramecium can look like a twirling top as it spirals through the water.

How Cilia Work

Paramecium use small hairs called cilia for movement purposes.
Paramecium use small hairs called cilia for movement purposes.

Many other single-celled organisms use cilia for propulsion, and some use a flagellum — a single, long, whip-like appendage. The two are quite similar in design, and operate in the same way. Although they appear to be just simple hairs, their structure is in fact quite complex.

A cilium consists of a hollow, flexible cylinder, made from nine pairs of tiny tubes known as microtubules. Another pair of microtubules runs through the center, connected to the surface by spokes. Each pair of microtubules has two protein molecules, known as dynein arms, attached to it at intervals along its length. These act like tiny motors, using adenosine triphosphate (ATP) as a source of energy. To achieve movement, they push in unison against the neighboring microtubule pair, causing it to bend in the desired direction.

Paramecia may be observed under a microscope.
Paramecia may be observed under a microscope.

This happens very quickly, and the combined action of these little motors causes the cilium as a whole to bend one way or the other, as required. Together, the coordinated action of many cilia can propel a paramecium at quite a speed, often making them difficult to observe clearly. The fine details of cilia cannot be seen with an ordinary microscope — their structure was revealed by examining cross sections using powerful electron microscopes. The study of cilia may help with the design of useful nanomachines.

Observing Paramecia

Paramecia can usually be obtained from pond or ditch water, especially near decaying vegetation such as dead leaves, which provide a rich food source in the form of bacteria and other microorganisms. A drop of this water placed on a microscope slide, with a cover slip on top, will usually reveal these little creatures. To see the cilia well, a magnification of perhaps 300-400 times is best, and it may be necessary to adjust the lighting to highlight these tiny, transparent structures.

A common problem with observing paramecia, especially at higher magnifications, is that they simply move too fast for their detailed structure to be clearly seen. Scientists, therefore, sometimes resort to various methods of slowing them down. These include using viscous fluids, and providing food, such as yeast, which they will graze upon, reducing their movements.

Interesting Paramecium Facts

A paramecium is shaped roughly like a shoe or slipper, with a covering of cilia and a groove that acts as a mouth. The beating of the cilia, aside from providing propulsion, also creates currents in the water that drive food particles into the “mouth.” Despite being single celled, the organism is quite complex, with a nucleus containing genetic material, and easily identifiable organelles — miniature organs.

Among these are one or more contractile vacuoles, which gather and expel excess water. Food particles, once “swallowed,” form food vacuoles: little “bags” that surround the food and through which nutrients are absorbed. By feeding paramecia yeast stained with a dye, the formation and progress of these vacuoles can be followed. Like most other single-celled organisms, paramecia usually reproduce by simply dividing in two — the nucleus splits first, duplicating the DNA. They are also capable of conjugation: a primitive form of sexual reproduction in which two organisms temporarily fuse together and exchange genetic material before dividing.

Frequently Asked Questions

What mechanism do paramecia use to move?

Paramecia move using tiny hair-like structures called cilia that cover their entire surface. These cilia beat in coordinated waves, propelling the organism through water. This movement, known as ciliary locomotion, allows paramecia to swim forward, backward, and rotate, giving them remarkable maneuverability in their aquatic environments.

Can paramecia change direction, and if so, how?

Yes, paramecia can change direction by reversing the beat of their cilia. When they encounter an obstacle or unfavorable conditions, they can perform an avoidance reaction, where they briefly reverse the direction of ciliary beating, back up, and then pivot to move away in a new direction, effectively navigating around impediments.

How fast can paramecia move?

Paramecia are relatively swift for their size. They can travel up to several times their body length per second. For instance, a typical paramecium can cover a distance of 2.5 millimeters per second. This speed is quite efficient for escaping predators or moving towards favorable environments in their microscopic world.

Do paramecia have any specialized structures for movement?

Aside from the cilia, paramecia possess an oral groove that aids in feeding and can also affect movement. The oral groove's ciliary action can create water currents that help draw food into the cell mouth. While primarily for feeding, these currents can also contribute to subtle shifts in the paramecium's movement.

How do paramecia respond to environmental stimuli when moving?

Paramecia exhibit a behavior known as taxis, where they move in response to environmental stimuli. For example, they can perform chemotaxis, moving toward or away from certain chemicals, or phototaxis, moving in response to light. These responses are crucial for survival, helping them find food or avoid harmful conditions.

Is the movement of paramecia affected by the viscosity of the water they inhabit?

The movement of paramecia can be influenced by the viscosity of the water they inhabit. In more viscous environments, their cilia must exert greater force to achieve movement, which can slow them down. Conversely, in less viscous water, paramecia may move more easily and rapidly, demonstrating the adaptability of their locomotion to different conditions.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...
Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a AllThingsNature researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

Learn more...

Discussion Comments

ButterPecan

Watching videos of paramecia moving is surprisingly mesmerizing.

anon304506

How do they move with their hair?

pleonasm

@MrsPramm - Even if someone can't afford that kind of microscope and camera, you can still check out paramecium on Youtube. It's a good way to answer the question of how do paramecium move without having to actually imagine it.

It can be difficult to figure out movement from a textbook description. And, unfortunately, even simple microscopes tend to be very expensive.

MrsPramm

@anon88643 - You might not have been using a strong enough magnification. Without being able to see the cilia you can't really see the "spinning" effect. It's also difficult to see it in general because you're looking down on the paramecium, rather than from a different angle.

The best way to see it (and a wonderful resource for schools in particular) is to get a video microscope set up so that the paramecium can be viewed on a large screen TV.

My father was head of technology at my high school when I was younger and he had that kind of set up. It was really amazing the kinds of things you could see with it.

anon227892

How does a paramecium communicate with others?

anon133159

That's exactly what I saw! Great confirmation.

anon88643

they don't look like they spin while viewed under a microscope.

anon55818

what are paramecium? besides being a unicellular organism.

anon40689

what type of nervous control is found in the paramecium ?

wendy1

What type of nervous control is found in the Paramecium?

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    • Three paramecia.
      By: micro_photo
      Three paramecia.
    • Paramecia.
      Paramecia.
    • Paramecium use small hairs called cilia for movement purposes.
      By: Matthew Cole
      Paramecium use small hairs called cilia for movement purposes.
    • Paramecia may be observed under a microscope.
      By: kasto
      Paramecia may be observed under a microscope.