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Diatoms. By: Jared Williams Andre Pierre-Louis Chris Terrell. Appearances.
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Diatoms By: Jared Williams Andre Pierre-Louis Chris Terrell
Appearances • Diatoms can form small colonies, and filaments have been seen to measure over two feet. The size of these very diverse micro-organisms varies greatly. There is a yellow tint that can be seen due to photosynthetic plastids. When observed as larger masses, the color takes on a darker color, often deep brown or black. Some diatoms also have a blue or green color, but these are the exceptions.
Habitat • Diatoms are found in both fresh water and salt water. There in fresh water habitats mostly in the spring and fall months. Not only do diatoms live in streams, lakes and other bodies of fresh water, but they can be found on the rocks, plants, and mud that is nearby or at the borders of the water.
Ocean Location • Ocean Location:Diatoms can be found within the range of the tides and water that covers the ocean bottom regions. They are classified as either pelagic (existing within the water column) or benthic (existing on the seafloor).
Microscopic Appearance • Cell Wall: The cell wall is composed mostly of silica (SiO2). This term refers to the frustules and the organic stuff that covers the valves and girdle. • Frustules: The frustules contain two valves that fit within each other (one valve is smaller than the other. The frustules can have all different shapes symmetrical as well as asymmetrical. • Epitheca: This term is used to refer to both the larger older valve of the frustules as well as the girdle elements that are connected with it.
Growth • The different manners in which diatoms grow and live are definitely an sign of their diversity. Some diatoms grow by there self, while others may grow as a group or filaments that anchor them to surfaces. Some grows on another plant upon which it depends for mechanical support but not for nutrients , while others exist as parasites. Though some diatoms may be sessile, there are many that are free due to structures that allow movement. Those diatoms that do form colonies are usually liked by siliceous, mucilage, or polysaccharide structures.