1. Diatoms

2. Diatoms! Diatoms are a major group of eukaryotic algae Diatoms are the most common type of phytoplankton They are unicellular Some diatoms form simple colonies & chains Diatoms are encased with a unique cell wall made up of silica This wall consists of two symmetrical sides with a split between them Diatoms have an extensive fossil cord going back to the Cretaceous

3. Things to know! Diatoms are completely abundant in both fresh water and salt water marine ecosystems. 25% of all carbon fixation is carried out by diatoms. Diatoms contain chlorophyll Diatoms are a major food resource for marine and fresh water organisms and animal larvae Diatoms are a major source of atmospheric oxygen Not all diatoms are free floating, some cling to surfaces such as aquatic plants, mulloscs, crustaceans, and even turtles.

4. Some more things to know! Diatoms only construct new cell walls during cell division After the cell divides, the epitheca and hypotheca separate, and new valves are laid down between them. There are more than 200 genera of living diatoms, and it is estimated that there are approximately 100,000 extant species Diatoms belong to a large group called the heterokonts, including both autotrophs