Diatoms: Diatoms are a major group of algae specifically micro algae. They're a single-celled alga which has a cell wall of silica. Many kinds are planktonic, and extensive fossil deposits have been found. They are most commonly found in oceans, waterways, and soils of the world.
Cyanobacteria: Also called blue-green algae, they are photosynthetic microscopic organisms found in all types of water. They are similar to bacteria but they use the sunlight to produce their own food.
Radiolarian: A single-celled aquatic animal that has a spherical amoeba-like body with a spiny skeleton of silica. Their skeletons can accumulate as a slimy deposit on the seabed.
Bacteria: Unicellular biological cell/microorganism that has cell walls but lacks a nucleus and organelles. Typically a few micrometers in length, bacteria have a number of shapes, ranging from spheres to rods and spirals. They were among the first life forms to appear on Earth, and are present in most of its habitats.
Foraminiferan: They are a single-celled planktonic animal with a perforated chalky shell through which slender protrusions of protoplasm extend. Most kinds are marine, and when they die, their shells form thick ocean-floor sediments. Is a member of a phylum or class of amoeboid protists.
Dinoflagellates: A single-celled organism with two flagella, occurring in large numbers in marine plankton and also found in fresh water. Some produce toxins that can accumulate in shellfish, resulting in poisoning when eaten.
Phaeophyta: Brown algae in the class phaeophyceae. A large group of multicellular algae, including many seaweeds located in colder waters within the Northern Hemisphere. Most brown algae live in marine environments, where they play an important role both as food and as habitat.
Rhodophyta: Red algae, or Rhodophyta, are one of the oldest groups of eukaryotic algae. The Rhodophyta also comprises one of the largest phyla of algae. They have specialized pigments, no flagellate structure, and no sexual process.
Chlorophyta: Chlorophyta or Prasinophyta is a taxon of green algae informally called chlorophytes. They are autotrophic, reproduce both sexually and asexually, and are mostly aquatic.