1. “The Microbial World” Unicellular Algae (Part 2)
Chapter 5
“The Microbial World”
Unicellular Algae
(Part 2)

2. Bell Ringer Compare and Contrast Osmoconformers vs Osmoregulators
What is the correct way to write a Taxonomic Binomial Name?

3. MARINE BIOLOGY Essential Question:
What are the examples of unicellular organisms?
Learning Goals:
Learn different unicellular organisms
Agenda:
Bell Ringer
Review quiz
Finish Chapter 5 (1)
Start/Finish Chapter 5 (2)
CNN/10 (3rd and 7th only)
Upcoming:
Chapter 6
Exam on 4.3, 4.4, 5, & 6 (11/14 – 11/15)

4. Unicellular Algae
Algae are a diverse group of Eukaryotes who are, mostly, aquatic and photosynthetic organisms (There are exceptions)
Photosynthesis takes place in chloroplast (Green, Brown, Red)
The colors of algae results from the concentration of their pigments
Algae are NON-flowering plants, and do NOT have true leaves, stems, or roots.
They have SIMPLE reproductive structures & non-reproductive cells

6. Unicellular Algae (cont.)
Unlike plants, however, Algae have structures similar to animals.
Some species of algae use flagella to swim
Some species eat food particles like animals
Some species are claimed in kingdom Animalia and Plantae.
Protists (“Protiston”: first of all ones): Diverse group of microorganisms comprised of algae, protozoans, and fungi.
Can be found in all moist/wet environments.
Can be autotrophic or heterotrophic.
Originally classified as Kingdom Protista.
Kingdom Protista NO-LONGER exists! But we still use it to identify.

7. Diatoms Diatoms (6000 species are Marine) Mostly Unicellular
Phylum: Heterokontophyta
Mostly Unicellular
Can aggregate into chains or star-like groups
Enclosed by cell walls made of GLASS! (SiO2)  Most notable feature!
Frustule (Glass Shell): two tight-fitting halves with perforations and ornaments (spines and ribs).
Glass allows passage of light for photosynthesis
Perforations allow gas exchange.

9. Diatoms (cont.) Buoyancy Photosynthesis Mobility Pathology
Water column decent is slowed by microdroplets of oil within their cells and spines on the frustules.
Photosynthesis
Yellow-Brown Carotenoid pigment containing Chlorophyll a & Chlorophyll c
Produced large amounts of Oxygen and serve as food for primary consumers!
A few species are heterotopic (with NO photosynthetic ability)
Mobility
Mostly Planktonic but some have stalk for attachment to surfaces.
Ex. Brown scum in mudflats or glass aquarium = millions of diatoms!
Pathology
Some produce Domoic Acid, which accumulates in shellfish and plankton consuming organisms.
Domoic Acid affects the Central Nervous System and can be fatal!

10. Diatoms (Cont.) Reproduction Blooms Death Asexual & Sexual
Periods of rapid reproduction due to highly favorable conditions.
Produces progressively smaller diatoms due to asexual reproduction and depletion of silica in the water.
Death
Upon dying, their glass frustules sink and contribute to biogenous sediment
Diatoms contribute to Diatomaceous Ooze which adds to diatomaceous earth.

11. Dinoflagellates Dinoflagellates
Phylum: Dinoglagellata
All dinoflagellates have two flagella.  Most notable feature!
One wrapped around a groove along the middle of the cell
One trailing free
Cell wall
Plated appearance
Composed of cellulose (similar to seaweed and land plants)

13. Dinoflagellates (Cont.)
Metabolism
Autotrophic (Photosynthetic) and Heterotrophic
Mobility
Planktonic with preference to warm water
Blooms
Periods of rapid reproduction due to highly favorable conditions
Forms Red Tides (can be Reddish-Brown or Yellow)
Some species release harmful toxins during blooms!
Other species produce light during blooms!

16. Dinoflagellates (Cont.)
Zooxanthellae
Golden-Brown Dinoflagellates that live in close association with other animals
Ex. Sponges, Sea Anemones, Giant Clam, and Coral!
They fix carbon and release organic matter used by coral to help them form their exoskeleton.
Pfiesteria
Parasitic dinoflagellate dubbed “Phantom Dinoflagellate”
Spends life mostly in “Cyst” stage in the sediment
When conditions are adequate Pfiesteria blooms can cause sores by feeding on fish and harm crabs, oysters, clams, and humans too (memory loss)

18. Other Unicellular Algae
Silicoflagellates
Star-shaped Exo-Skeleton (Silica)
Two flagella (different Lengths)
Coccolithophorids
Flagellated & Spherical
Covered in Calcium Carbonate Coccoliths (“Buttons-Like”)
Cryptophytes
Two Flagella
No skeleton
Contains Chloroplast within cell INSIDE the cryptophytic cell.

19. Protozoans
Protozoans (“Protos”: first; “Zoion”: Animal): structurally simple and diverse eukaryotic organisms that are traditionally “animal-like”
Only real commonality is being composed of a single cell (some colonize)
50,000 different species of protozoans (Grouped into “Protists”)
Metabolism
Heteroprophic (Some contain Chloroplast and photosynthesize)
Supercells
Can carry out many of the complex functions delegated to different cells in a multicellular organism.

20. Foraminiferans Foraminiferans Shell (“Test”) Feeding
Phylum: Granuloreticulosa
Shell (“Test”)
Composed of Calcium Carbonate (CaCO3) like coral and will grow with age.
Test can grow to 2 inches and contribute to Foraminiferan Ooze when they aggregate as biogenous sediment. (ex. Pink Sand Beaches)
Feeding
Long, thin and retractable pseudopodia (extensions of the cytoplasm) that protrude through pores in the test.
Pseudopodia are used to trap food (diatoms)

22. Radiolarians Radiolarians Shell (“Test”) Feeding Phylum: Polycystina
Composed of Glass (SiO2) like Diatoms but with radiating spines.
Colonies can be 9 feet in length and contribute to Radiolarian Ooze (in deeper waters) when they aggregate as biogenous sediment.
Feeding
Long, thin and retractable pseudopodia (extensions of the cytoplasm) that protrude through pores in the test.
Pseudopodia are used to trap food (diatoms)

23. Ciliates Ciliates Feeding & Locomotion Unusual Habitat Loricas (Test)
Phylum: Ciliphora
Feeding & Locomotion
Hair like cilia (like Paramecium)
Unusual Habitat
Clam gills, Urchin intestines, Fish Skin, other unusual places.
Loricas (Test)
Vase like shell structure built by Tintinnids (Common Ciliates) from sand grains, etc.

24. Fungi Fungi Metabolism Parasite Symbiosis Kingdom: Fungi
500 known species
Metabolism
Heterotrophs
Decompose detritus (mangrove)
Parasite
Affect important seagrass, fish, sponges, and shellfish.
Symbiosis
Lichens: combination of fungi with algae
Fungi filament provide support for algae growth.