Radiolarians

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.