The Foraminifera are single celled, mainly benthic, marine to brackish water protozoans that are amoeboid in shape (1A) but produce mainly calcareous tests (3 & 4) (some aggregate sediment particles in a hardened mucus (2)) through which extensions of the ectoplasm form parapodia (2, 3, 6 & 9). These extensions are used for motility, anchoring to the sediment and to capture prey (diatoms and bacteria). The taxonomy of this group is disputed as they are possibly grouped with radiolarians and cercazoans in the Infrakingdom Rhizaria. All of these groups are important in carbon recycling as their tests sink carbon to the ocean floor from the atmosphere.
Radiolarians are a group of marine protozoa (single celled eukaryotes) which have intricate siliceous skeletons (blue structures). The skeletons both seperate the cell into two distinct inner and outer regions (7) (endo/ecto-plasm) and create long pseudopodia which increase surface area and aid in buoyancy. The endoplasm usually contains the nucleus (n) and other organelles whilst the ectoplasm often utilises gas filled vacuoles and lipid deposits to increase buoyancy (2). The ectoplasm also often have symbiotic algae (Gz) which photosynthesise to produce food for the radiolarian (2 & 3). The taxonomy of this group is disputed as they are possibly grouped with foraminiferans and cercazoans in the Infrakingdom Rhizaria. All of these groups are important in carbon recycling as their tests sink carbon to the ocean floor from the atmosphere.
The old phylum of Protozoa is recognised to be a paraphyletic group containing a diverse range of taxa grouped together only because of their simple body plan lacking complete tissues and being somewhat heterotrophic. As such the clade Protozoa is now considered to be a paraphyletic kingdom containing meany phyla which are both related and un-related. The phylum Ciliophora contains many large complex protozoans which utilise the beating of hair like structures called cilia to create movement of either themselves or the medium which carries their food to them.