Domain Eukarya/Straminopiles/ Diatoms
Link to diatom image directory
Eukaryotic, photosynthetic organisms with
chlorophylls a and c. Mostly unicellular though some form filaments
and loose colonial aggregations. Their walls are made of silicon
and consist of two parts that connect together like a pill box.
The face-view of a cell encompassing an entire part is a valve-view, a view showing
where these parts overlap is a girdle-view. These organisms
are the most important primary producers in the world's waters.
Are bilaterally symmetrical in valve-view.
Many are motile when in contact with a substrate, and live in
sediments, on rocks ect. and, hence, are important primary producers
in shallow waters.
Are radially symmetrical in valve-view. Are
typically part of the planktonic community, hence, are important
producers in deep waters such as ocean environments.