About the Book
Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 28. Chapters: Actinocyclus normanii, Asterionella, Attheya, Attheya arenicola, Attheya armata, Attheya decora, Attheya flexuosa, Attheya gaussii, Attheya longicornis, Attheya septentrionalis, Auxospore, Bacillaria, Bacillariaceae, Bacillaria paxillifer, Bacteriastrum, Bacteriastrum delicatulum, Biddulphiophycidae, Briggera, Chaetoceros, Chaetoceros diadema, Chaetoceros furcellatus, Chaetoceros pseudocurvisetus, Chaetocerotaceae, Clepsydra (genus), Coscinodiscaceae, Coscinodiscophyceae, Coscinodiscophycidae, Craspedodiscus (protist), Craspedodiscus elegans, Craticula, Diatom, Didymosphenia geminata, Eupodiscaceae, Fragilariophyceae, Frustule, Hyalodiscus, Navicula, Naviculales, Nitzschia, Odontella, Odontella aurita, Pennales, Phaeodactylum tricornutum, Pinnularia, Pseudo-nitzschia, Rhizosoleniophycidae, Stilus, Tabellaria, Terpsinoe, Thalassiosira pseudonana, Thalassiosira weissflogii, Triceratiales. Excerpt: Diatoms are a major group of algae, and are among the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons (e.g. Fragilaria), fans (e.g. Meridion), zigzags (e.g. Tabellaria), or stars (e.g. Asterionella). Diatoms are producers within the food chain. A unique feature of diatom cells is that they are encased within a cell wall made of silica (hydrated silicon dioxide) called a frustule. These frustules show a wide diversity in form, but are usually almost bilaterally symmetrical, hence the group name. The symmetry is not perfect since one of the valves is slightly larger than the other allowing one valve to fit inside the edge of the other. Fossil evidence suggests that they originated during, or before, the early Jurassic Period. Only male gametes of centric diatoms are capable of movement by means of flagella. Diatom communities are a...
