Small backyard ponds could be an interesting part of your garden. Building a miniature pond is a great way of bringing a whole new ecosystem into your garden. A healthy pond will quickly fill with plants and animals that are unique to the pondside lifestyle. You may see invertebrates like dragonflies, snails, and water boatmen hanging around your tiny pond. Some cool amphibians such as frogs and newts will visit your garden in the summer. You can even have goldfishes living in your backyard pond.
More interestingly, except for these plants and animals, there is an invisible world, alive with an amazing variety of microscopic organisms that you can only see under a microscope. You can find simple life forms like bacteria, great oxygen-producers like algae, all kinds of alien-like protozoans, and cute microscopic animals like water bears.
Common Microscopic Organisms in Your Pond Water
In this post, let’s talk about 10 common microscopic organisms you can find under a microscope in your pond water.
- Green algae
1. Green algae
Green algae are important nutrient-producers that can obtain the energy to grow through photosynthesis. Green algae serve as food sources for many other microscopic creatures. Some green algae grow in long filaments like a brush of green hairs, while others are free-floating single cells or clusters of many cells.
[In this figure] Filamentous green algae, Spirogyra under a microscope.
Diatoms are free-floating brown microalgae. A unique feature of diatom cells is that they are enclosed within a silica shell called a frustule. This shell gives diatoms colorful and shining appearances.
Euglena is a unique microorganism that shares both characteristics of plants and animals. Euglena contains chloroplasts; thus, they can make their own food, a characteristic of plants. In contrast, euglena can also move using its flagella and consume food through phagocytosis.
Amoeba is a group of primitive protists known for the way they move – a transformative crawling manner – through extension and retraction of “false feet”. Amoeba does not have a fixed shape – it constantly changes.
[In this video] The Microanatomy of Amoeba – Show you the secret of amoeba under a microscope!
Paramecium is a single-celled microorganism with a shape resembling a slipper. Paramecium can swim around by waving these tiny hairs (called cilia) covering its entire body. The cilia of Paramecium move like many tiny oars, propelling the organism through the water at a rate that is “four times its body length per second”. That said, if a paramecium is as tall as a human being, it can swim four times faster than Olympic gold medalist Michael Phelps.
Stentor, sometimes called trumpet animalcules, is a cousin of Paramecium. Its body is generally horn-shaped. A ring of cilia around its “mouth” sweeps in food and aids in swimming.
[In this video] Stentors under a dark-field microscope.
Rotifers are microscopic aquatic animals. Rotifers got their name from the corona: a rotating, wheel-like structure covered with cilia at their heads. Rotifers are filter-feeders that eat dead material, algae, bacteria, and other microscopic living organisms; therefore, they are very important components of aquatic food webs.
Planarian is one type of flatworm that is free-living and harmless. They have two eyespots that can detect the intensity of light and primitive brains and nervous systems. Planarian has a remarkable regeneration capability. For example, a planarian cut into three pieces (head, body, tail) will regenerate into three separate individuals. You can even create a three-headed planarian if you make two incisions on its head.
[In this figure] Planarian regeneration. (A) The most frequently used Planarian in high school and first-year college laboratories is the brownish Girardia tigrina. (B-C) Diagrams of the main planarian regeneration experiments.
Tardigrades, also known as water bears or moss piglets, are very interesting organisms. Tardigrades look like chubby, microscopic bears walking slowly with eight short legs. Of no doubt, tardigrades are the cutest tiny creatures you can find under a microscope. Tardigrades represent a very successful group of animals. They can survive in many extremely harsh conditions. Some of them even survived through a space trip!
Daphnia (also known as water flea) is a group of small crustaceans. The body of Daphnia is usually 0.2-3 millimeters long, which is pretty tiny compared to their cousins, such as crabs and lobsters.
[In this figure] Left: An illustration of body parts of a Daphnia pulex. Right: A dark-field microscopic picture of a Daphnia pulex.
Having a small pond in your backyard can be very interesting. Aside from plants and marine animals, you can also find interesting creatures like the 10 most common microscopic organisms discussed above. Examining these microorganisms can be very fun and educational. It can be a stress reliever too. So, what are you waiting for? Get that microscope and start collecting your specimen.