Kingdom: Protista Animal-like Protozoans (protists)

Characteristics Eukaryotes Hetertrophic-feed off other organisms Most are microscopic 27,000 species Have endoskeletons and exoskeletons

Habitats 1. Aquatic Habitats: fresh and saltwater Zooplankton-hetertrophic protozoa that live in the ocean 2. Moist soil: upper layer of soil can include 40,000 species 3. Body tissue, plants, and animals

Nutrients Obtain nutrients directly from environment Oxygen, potassium, and other dissolved substances pass through cell membrane by diffusion-moving from greater concentration to lesser concentration Also expel waste such as carbon dioxide, ammonia, and other molecular wastes through diffusion Some protozoa can engulf large food particles through phagocytosis

Relationships & Classification: Protozoa can live independently or in symbiosis Protozoa can live by means of parasitism, mutualism, commensalism Protozoa are motile organisms-use energy to move freely Nonmotile (sessile) protozoa are parasites that live in rich food supplies such as the bloodstream Protozoa are classified according to their method of movement

Phylum: Sarcomastigophora Have flagella, pseudopodia or both Subphylum Mastigophora –One or more flagella –Volvox, Giardia, Trypanosoma, Euglena Subphylum Sarcodina –Pseudopods –Amoeba, Radiolarians

Phylum Apicomplexa Parasitic Apical complex – penetrates host cells Plasmodium, Toxoplasma

Phylum Ciliophora Lots of cilia Heterotrophs Macronucleus and micronucleus Paramecium, Stentor, Euplotes, Vorticella

Zooplankton There are protists that can be found in plankton samples. The three most common all have shells. Their shells are often found in marine sediments.

Tintinnids Tintinnids are marine protists that secrete a vase-like shell or lorica that protects them when they withdraw.They are filter feeders.

Foraminifera Forams are amoeba like organisms that have a calcareous shell. These shells are very important in marine sediments.

Radiolaria Radiolarians are amoeba like organisms with a skeleton formed of silica. They are common in colder waters where their shells can dominate the sediments.