Microorganisms in Pond Water

Don't let the still waters of a pond fool you. Every drop of water in ponds and lakes is teeming with such various life forms that it would be difficult for one to even conceive unless he sees it with his own eyes. Besides the various pond insects that we all are so familiar with, there are a large number of microorganisms in pond water. Let us take a look at this world in the liquid environs of pond water that eludes the naked eye.

Microorganisms in Pond Water

Bacteria
Bacteria is a large group of single celled organisms that are found in every corner of the earth, be it land, air or water. There are approximately 5×10³⁰ bacteria on the earth that form a major part of the biomass. These are prokaryotes that lack a nucleus and membrane bound organelles. They come in different shapes and sizes. Cyanobacteria are very commonly found microorganisms in water. The bluish-green color water in pond or ditches is attributed to these organisms. Nostoc and anabaena are common cyanobacteria that are found in pond water. Spirochaete bacteria is another group of bacteria commonly found in pond water that unlike cyanobacteria have numerous hair like structures that make them fast movers.

Protozoa
Protozoans are unicellular eukaryotes that in contrast to prokaryotes have a nucleus that encloses the genetic material. Their cells also have membrane bound cell organelles. Euglena is a microorganism in ponds that moves with the help of flagella. Amoeba forms another group of protozoa that move with the help of pseudopodia or false feet. Ciliates like paramecium, vorticella and ophrydium move in water with the help of their numerous small hair like structures called the cilia.

Algae
Algae are another diverse group of plants that may be unicellular or multicellular but are essentially autotrophic, that is they manufacture their own food through the process of photosynthesis. Some of the common algae found in pond water are chlamydomonas, euglena and spongomonas. While chlamydomonas is a free swimming flagellate, spongomonas use their flagella to collect food instead of moving around, and live in a gelatinous matrix. Volvox is an alga that lives in colonies. Diatoms, spirogyra, oedogonium, cladophora, zygnema and porphyridium are some filamentous types of alga that are common microorganisms found in water. Read more on what is spirogyra.

Rotifers
Rotifers are a type of multicellular micro-animals that are most commonly found in fresh water, although some forms are also adapted for life in salty waters of the seas and oceans. These animals get their name from the tuft of cilia that is present at the front of the body around their mouth. They use their cilia to propel themselves and also direct food into their mouth. However, not all rotifers are dependent on cilia for locomotion. Most free-living forms have two toe like structures in their posterior end with which they attach themselves to the substrate while feeding. Rotifers' diet include algae, dead bacteria and waste of fishes.

Hydra
Hydra is another fresh water animal that is most commonly found in pond water. This animal belongs to the class hydrozoa the members of which live mostly in marine water. Hydra is a predatory animal that hunts its prey with the help of specialized stinging cells called cnidocytes. These stinging cells are present in the tentacles that surround the mouth. On the other end of the tubular body of the hydra is a basal disc or foot with which the hydra attaches itself to the substratum.

Identifying Microorganisms in Pond Water

The best method of identifying microorganisms in pond water is to collect some pond water and observe it under a microscope. The materials required for this activity are:

• Compound microscope
• Microscope slides
• Cover slips
• Eye Dropper
• Pond water

Collect some pond water in a jar. Pour one drop of this water in a microscope slide. Cover the drop gently with a cover slip. Do not press the cover slip on the slide with your finger. Now place the slide under the lens of the microscope and observe the microorganisms in pond water. It is always best to use a fresh sample of pond water.

The various microorganisms in pond water along with all the other larger forms play specific roles in the pond ecosystem. This was less than a trailer of the spectacular movie that the world in a drop of pond water is. To see all of it you will have to collect some pond water and observe it more than just once.