Diatoms Facts

A major group of algae is recognized as diatoms. Most diatoms are unicellular organisms. Filament, fan, zigzag or ribbon shaped colonies of diatoms also exist and they can be noticed easily in freshwater and marine environment. For instance, fragillaria, meridion, tabellaria, etc.

Facts About Diatoms

Diatoms are microscopic, single-celled or colonial plant-like organisms whose cell walls are composed of silicon dioxide (silica). There are numerous holes or areolae on diatom shells (or tests) which are visible under a light microscope.

They are found on damp surfaces, in the oceans, in freshwater, in lakes, streams, estuaries, puddles, wet rocks and in soils, almost anywhere where there is water and light. Most Diatoms are microscopic but some species are as long as 2 millimeters. They usually do not move, but some do move via flagellation.

From diatoms classification, we know that they belong to the class Bacillariophyceae and there are more than 200 genera of living diatoms. They are classified as either protists or chromists. According to the estimates there are approximately 100,000 existing diatom species. Two types of diatoms, the round centrales and long or pen-shaped pennales are well-known.

The characteristic property of diatoms which makes them unique forms of algae is that they grow a silica shell that is preserved in underwater sediments after they die. The diatom shell is known as frustule which is different for each species, so you can identify them by observing through a microscope. These frustules exhibit two asymmetrical sides with a split between them. Because of this the group is known as diatoms. They are mostly yellowish or brownish and they have chlorophylls a and c and the carotenoid fucoxanthin contained in plastids. They produce food by photosynthesis. They are great suppliers of oxygen.

Diatoms reproduction is a wonderful phenomenon. They undergo asexual reproduction as they reproduce by cell division. The diatom becomes smaller with each round of replication. Read more on organisms that reproduce asexually. Diatoms facts reveal that very small diatoms may follow a sexual mode of reproduction which allows for growth of a relatively large zygote. Thus, they have a solution for an ever-shrinking asexual mode.

As they die they drop to the bottom. Diatom shells, not being subject to decay accumulate in the ooze and finally form the material known as diatomaceous earth which is also known as kieselguhr. Diatomaceous earth found in the form as a soft, chalky, light-weight rock is called diatomite which is used as an insulating material to absorb both heat and sound. It is used to manufacture dynamite and other explosives and also for filters, abrasives, etc. It is sometimes used in gardening as a pest control.

One of the most amazing diatoms facts is that they play an important role in the structure of the earth as the limestone layers are deposited by them and much petroleum is also of diatom origin. Diatoms communities provide a tool for monitoring past and present environmental conditions. They are useful in studies of water quality. Studies show that different diatom species prefer different temperatures. Therefore, scientists can estimate the temperature of the water they live in. Diatoms present in greater number and their size help indicate lateral water movement and how well the water is mixed.

The world of diatoms is just amazing and study of microorganisms can be really fascinating for those interested in it, as it throws light on different geologic ages.