Fun Science - World in Pond Water

Explore microscopic life in a local pond, marsh, or stream. A cup of water can contain millions of microorganisms. Seeing tiny single celled organisms through a microscope really brings home to kids the concept of cells and the idea that there are living things too small to see with the naked eye.

Watching the tiny little creatures in a drop of water can be endlessly fascinating. So many tiny forms of life that humans never knew about before microscopes were invented only about 400 years ago.

What do you need?

Jar of Water - Take a jar to a local pond, marsh, or stream and fill it with water.

Microscope - A basic compound microscope is all you need.

Slides and Slide Covers- Most microscopes come with some blank slides or you can buy them separately. For this you will need well slides, these have a small dip in the center.

Eye Dropper - For dropping a tiny bit of water onto your slide.

For help using a microscope either look in your microscopes instruction guide or check one of the links under How to Use a Microscope Links.

Common Microscopic Organisms

Protists:

Protists are single celled eukaryotic microorganisms (eukaryotic cells are those with a nucleus). Protists used to all be classified as a Kingdom but more recently that classification has proven to be incorrect, scientists are still working out where various types of protists such as protozoa (animal-like), algae (plant-like), and fungus-like protists belong in the tree of life.

Flagellated Protozoa - These protozoa move using a flagellum, a long tail-like structure.

Amoebas - These protozoa move and capture food by changing their body shape, reaching out psudopods (meaning false feet).

Ciliates - These protozoa are covered with tiny hair-like structures call cilia, they move by "rowing" with the cilia.

Algae - Algae are plant-like single celled organism that sometimes live in groups. They produce their food using photosynthesis just like plants (in fact many forms of algae are sometimes classified as plants).

Diatoms - Diatoms are a very interesting class of single celled algae. They form hard, rigid, cell wall out of silica (the same stuff a lot of sand and glass is made from).

Animals:

Crustaceans -The crustaceans are a large group of arthropods. Lobsters, crabs, shrimp, and barnacles are familiar crustaceans but many are also microscopic. Most crustaceans live in the water, either fresh water or salt water. They have segmented bodies and are the closest relatives of insects.

Worms - The name worm is used for many unrelated animals that evolved a slender elongated body shape.

Insect larva - Many insects lay their eggs in water, when they hatch these larva usually look nothing like the adult insects.

Rotifers - Rotifers are microscopic multicellular animals, and among the most ancient and primitive of all animals.

Plants

You are likely to see many tiny aquatic plants in your pond water, along with broken bits of larger plants such as leaves and roots, dependign on the time of year you many also see tiny seeds or pollen.

Bacteria:

Bacteria are the oldest known forms of life and comprise their own Kingdom. Most are barely visible under a microscope but some are large enough to see.