Chapter 6 Marine Microbes

(organisms invisible to the naked eye)

• Include viruses, one-celled organisms, and fungi.• Microbes play many different roles in marine

ecosystem. (structure leads to function)• Phytoplankton-planktonic algae• Zooplankton-larvae of small animals-ex fish, jellyfish• We will discuss 3 of these in detail that you will be

accountable for1. Diatoms2. Dinoflagellates3. Forams

Diatoms

• Most distinctive of plankton samples• Low latitudes-occur in coastal waters• Phytoplankton-Contributed to most of

primary productivity of an area.

Diatom Structure

• Glassy Cell wall• 2 valves- 1 large, 1 small• Visible geometrically shaped pattern-(helps

distinguish between species)• Size: 2 micrometers to 4 millimeters

Reproduction

• Asexually by fission• When cells divides, each daughter gets one of

the 2 valves• Eventually daughter that inherited smaller

valve will reproduces sexually

Dinoflagellates- structure

• Globular, single-celled organisms• 2 flagella that lie in groves on the center of

surface• Larger of phytoplankton• Look similar to soccer ball under microscope

Reproduction

• Asexually by fission– Split cell into two– Can happen at a rate of one division per day

• Sexual in some species by gametes

• If you had two species of Dinoflagellates and species A produced asexually while species B produced sexually, which species to you expect to survive throughout time longer and why?

• Zooxanthellae are collections of dinoflagellates– They lack flagella like most species– Mutualistic relationships with corals, jellyfish, and

mollusks.• Some species are responsible for Red Tide– algae bloom-large quick population boom– Produce toxins, usually cannot eat fish during this

time– http://www.youtube.com/watch?

v=auEePWRqj7Y&safety_mode=true&persist_safety_mode=1&safe=active

Goodby’s Creek in Mandarin during last Algae Bloom

Forams

• Have a pseudopod-organelle that is an extension of the cell surface– Used for locomotion and food capture

• Have a shell• deep as Marianas Trench• members of zooplankton

Foram Reproduction

• Asexual fission most species• Sexual reproduction-some species

• http://www.youtube.com/watch?v=Fpry23bS6g0&safety_mode=true&persist_safety_mode=1&safe=active

Exit Slip

• Using you knowledge and distinguish between phytoplankton and zooplankton

• Compare and contrast- Diatoms, Dinoflagellates, and Forams