Chapter 5- The Microbial World Bacteria Unicellular algae Protists The Microbial Loop Megaplankton Macroplankton Mesoplankton Microplankton Nanoplankton Picoplankton Fill in the blank A. Femtoplankton B. Mesoplankton C. Nanoplankton D. Microplankton A Primary Productivity 6CO 2 + 6H 2 O = C 6 H 12 O 6 + 6O 2 With rare (relatively) exceptions, all energy comes into the system via this pathway. Gross PP respiration = Net Production Many different measurement techniques for PP Global Net PP 1
Limiting Factors Light (irradiance or intensity)- graph Mixing- good and bad Nutrient availability Grazing- fast growth vs. fast food Two Main Classes of Cells Prokaryotic (Bacteria and Archaea) Pro = Before ; Karyon = Kernel No nucleus, DNA coiled up inside cell Eukaryotic (Everything else) Eu = True DNA inside membrane bound organelle inside cell, the nucleus 3 Domain Taxonomy of life Eukaryotic Cell (non bacterial) Prokaryotic Cell (bacteria) Major Groups of Phytoplankton 2
Why are they* all small? * Planktonic producers OLD Nekton The Microbial Web Protozoan Grazers NEW Kelp Paddies Sargassum Net Zooplankton Heterotrophic Bacteria Nano and Pico Phytoplankton Net Phytoplankton Dissolved Organic Matter (DOM) Prokaryotes Domain Eubacteria and Archaea Bacteria important in PP, as well as in decay/recycling of nutrients Possibly they are also the most plentiful species on Earth: a single ml of surface seawater may contain 1.000,000 cells or more. Worldwide, there are estimated to be 100 octillion individuals 10 29 Prochlorococcus (0.7 microns) Blue-green algae or Cyanobacteria Some of the first life on Earth Important nitrogen fixers in the marine system Heterocysts OLD Nekton Net Zooplankton The Microbial Web Heterotrophic Bacteria Protozoan Grazers NEW Nano and Pico Phytoplankton Their other BIG claim to fame? Net Phytoplankton Dissolved Organic Matter (DOM) 3
Diatoms- class Bacillariophyta Unicellular Centric and Pennate Shell (Frustule) walls made of Silica (SiO2) Epitheca and hypotheca Reproduction (asexual and sexual) Auxospores Diatomaceous/Siliceous Ooze Diatom Reproduction I am going: A. Too s l o w B. Just right C. Too fast 4
Dinoflagellata Swimming with bioluminescent dinoflagellates Two flagella, often cell has cellulose armored plates Cingulum and Sulcus Both photosyn. and not Zooxanthellae Calcium Carbonate White Cliffs of Dover Coccolithophores Diatoms are made of: A. Calcium Carbonate B. CaCO 3 C. Silica Dioxide D. Cellulose OLD The Microbial Web NEW Protistan plankton Nekton Protozoan Grazers Net Zooplankton Heterotrophic Bacteria Nano and Pico Phytoplankton Net Phytoplankton Dissolved Organic Matter (DOM) 5
Foraminiferans and Radiolarians Shell (test) of calcium carbonate (CaCO3) Feed with pseudopods Foraminiferan ooze Glass tests (Silica) plus others Pseudopods Radiolarian ooze (deep water) General Environment Chapter 6 The Macroscopic Algae Waves, currents, tides, upwelling all create turbulence which greatly affects the physical environment Little Stratification-Uniformly high nutrients. In shallow waters, wave/swell action impacts the bottom flora and Fauna Four main types of shallow-water benthos - Unvegetated sedimentary - Hard substrate - Kelp forest - Seagrass beds 6
Food webs in So. Cal. Kelp Forest The Macroscopic Algae Plant evolution begins in the sea Single celled Multicelled colonies But still have very little specialization between cells Three divisions of algae- all can be seen in tide pools Rhodophyta- Red Algae Phaeophyta- Brown Algae Chlorophyta- Green Algae The 3 groups of Algae Rhodophyta- Red Algae Chl. a, other accessory pigments, storage is Floridean starch Phaeophyta- Brown Algae Chl. a & c, other pigments, storage is Laminarin Chlorophyta- Green Algae Chl. a & b, other pigments, storage is Starch Typical Algae structure (Pneumatocyst) Algae structure Blade: which of these is algae? 7
Algae structure Pneumatocysts: N2, O2, and Co2 gas Singular and large, or small and many Algae structure Stipe: Flexible and strong (in some ways) Some with conductive tissues which move photosynthate down to lower parts Phaeophyta and the Evolutionary Adaptations of Seaweeds to a Physically Stressful Environment Multicellular with a minor degree of specialization Structural adaptations of thallus: holdfast, stipe, blades, gas bladders (pneumatocysts) Chemical adaptations: Cellulose walls w/ polysaccharides may incorporate calcium carbonate 3 Reproductive Cycles: Haplontic (zygotic), Diplontic (gametic) or Alternation of Generations (diplohaplontic,sporic cycle) Phaeophyta largest and most complex chlorophyll a, c, carotinoids and fucoxanthin, homology to diatoms and golden algae Flagellated spores storage is laminarin cell wall= cellulose and algin heteromorphic 8
Kelp Beds and Forests Kelp Harvesting Found in cold, temperate regions only. Large brown algae= kelp. Kelps obtain nutrients from water, so depend on turbulence to renew waters to avoid depletion. Form extensive 3-D habitat with several vertical layers= High species diversity Rhodophyta: distant relatives to Phaeophyta a separate kingdom? No flagellated stage mostly marine, tropical Chlorophyll a, carotinoids, phycobilins (phycoerythrin) Primary endosymbiosis storage = floridean starch cell walls are cellulose with agar and carageenan Broad coastal distribution Alternation of generations is common, rely on water currents Chlorophyta: share a common ancestor with terrestrial plants Cyanobacteria and primary endosymbiotic theory Chlorophyll a, b, carotinoids, Marine, FW, soil, freeliving and symbiotic Diverse body plans, colonial, multicellular storage=starch cell wall = cellulose Ulva: isomorphic alt of gen Biflagellated gametes conjugation 9
Epibionts Islands in the stream Numerous single-celled and colonial diatoms and other algae use large macroscopic algae as a home Floating Sargassum are true macroscopic pelagic seaweeds why are there not more who use this strategy? Kelp Rafts- Natural FADs Life cycles of most algae 2 multicellular phases- Alternation of Generation 2n n 2n n.etc. Sporophyte and Gametophyte One phase may be dominant in structure Examples Alternation of generations: a generalized scheme The life cycle of Laminaria: an example of alternation of generations 10
11