Exploring Zooplankton: Amoeba and Paramecium in Action

1. Kingdom Protista sometimes called the “Junk drawer” contains animal-like, plant-like and fungus-like organisms Plankton (zoo-/phyto-/myco)

2. Characteristics of Protists: • Eukaryotic cells • Most are unicellular, but some are “colonial” (many identical cells) • Most are motile (some sessile) • Most are aquatic (some terrestrial) • Reproduce asexually (some conjugate)

3. Animal-like Protists • Zooplankton (Protozoans) • All are heterotrophic • Classified based on how they move: • Sarcodines – move by changing their shape • Ciliates – move by rhythmic beating of cilia • Flagellates – move by long flagella

4. Zooplankton • Sarcodines – • Ciliates -

5. Zooplankton • Flagellates -

6. Zooplankton • We will study 2 examples of Zooplankton • Amoeba (sarcodine) • Paramecium (ciliate)

7. Sarcodines • Amoeba proteus • Phylum Sarcodina • Movement – formation of Pseudopods • - cytoplasm is in constant motion, pushing against the plasma membrane

8. Amoeba in Action

9. Amoeba • Food – heterotrophic and feed by Phagocytosis • Reproduction – Binary fission • Special structures • Pseudopods – “false feet” • Contractile vacuole – maintain homeostasis • Food vacuole

10. Amoeba

11. Ciliates • Paramecium caudatum • Phylum Ciliophora • Movement – swim by beating cilia • Paramecium movement • Food – ingest food using the following structures • Oral groove – cilia – cytostome – gullet – food vacuole • Paramecium feeding

12. Paramecium • Reproduction – Binary fission • - Conjugation – 2 paramecia line up their oral grooves and swap micronuclei.

13. Paramecium • Special structures: • Macronucleus – controls metabolism • Micronucleus - involved in conjugation • Contractile vacuoles – maintains (here it is) homeostasis • Ingestion structures • Anal pore – excretion of wastes • Trichocysts – defense mechanism

14. Paramecium