Designs of Nature: The Architectural Marvels of The Diatoms Showcased by Scanning Electron Microscopy (Sem)

drelayaraja By drelayaraja, 9th Jul 2010 | Follow this author | RSS Feed
Posted in Wikinut>News>Environment

As a marine/estuarine ecologist, I was always astonished by the shapes of diatoms that I collected from various water bodies. The diatoms, when studied under a scanning electron microscope (SEM), would take us to a different world of shapes and patterns. Here is a short scientific note on their shape and pattern.

What are diatoms?

Diatoms are unicellular (made up of single cell) algae, which forms the major group of the eukaryotic (with true nucleus) phytoplankton. They form the producers of the ocean. They are widely distributed throughout the upper layers of the oceans and are also found in fresh water or moist environments. Many of these diatoms exist in colonies and therefore appear to be made up of many cells. The shape of a colony can be filaments, ribbons, fans, zigzag and stellate.

Diatoms are encased with in a silicate cell wall, which are also called frustules or tests and their two valves typically overlap one other like the two halves of a petri dish. These frustules exhibit diversity in shape and pattern. There are over 80,000 recognized diatom species under 200 living genera, with many more being constantly identified.

Classification

Scientific Classification

Domain : Eukaryota
Kingdom : Chromalveolata
Phylum : Heterokontophyta
Class : Bacillariophyceae
Orders : Centrales, Pennales

Diatoms are traditionally divided into two orders:

Centric diatoms (Centrales): These are radially symmetric.

Examples: Actinoptychus heliopelta, Biddulphia aurita

Pennate diatoms (Pennales): These are bilaterally symmetric.

Examples: Navicula sp., Ceratium sp.

Designs of Nature

Diatoms are usually microscopic, but some species of diatoms can reach up to 2 millimetres in length.

The siliceous wall of the diatom can be highly patterned with a variety of pores, ribs, minute spines, marginal ridges and elevations. These features help us to identify different genera and species.

The cell itself consists of two halves, each containing an essentially flat plate or valve and marginal connecting or girdle band. Diatom morphology varies, typically though the shape of the cell is circular, although, some cells may be triangular, square or elliptical.

Hope you have enjoyed the beauty of nature's creation. There are thousands of such spectacular designs that has paved way for many great ideas.

© 2010 Dr.P.Elayaraja

Tags

Algae, Biology, Centric, Design, Diatom, Drelayaraja, Ecology, Elayaraja, Electron Microscope, Marine, Pennate, Phytoplankton, Plankton, Producer, Sem, Water

Meet the author

author avatar drelayaraja
I am an Instructional designer engaged in e-learning content development. I have a passion for photography and poetry.

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Comments

author avatar Jenny Heart
17th Jul 2010 (#)

Excellent!

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author avatar Retired
6th Aug 2010 (#)

thanks for the share, excellent.

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