Title: A cyanobacteria bloom
1Phytoplankton
MARE 444 Lecture 2
2Phytoplankton
- the majority of the plants in the ocean are
planktonic unicellular algae called
phytoplankton. - some can be caught be nets, others can only be
collected by filtering or centrifugation (e.g.,
nano- and picoplankton).
3Phytoplankton
- Group Phycological Terminology
- Diatoms Bacilliariophyceae
- Dinoflagellates Dinophyceae
- Microflagellates Haptophyta, Prymnesiophyta,
- Chrysomonadales,
- Cryptomonadales
- Picoplankton Photoautotrophs lt 2µm
- Cyanobacteria Cyanophyta, photosynth bact.
- Prochlorococcus Photosynth bacteria
- Eukaryotic Pico Very small, struct. advanced
4Phytoplankton
- Vital role in marine food chain
- 4000 species of phytoplankton have been
described, new species are continually being
described - At least 13 classes of marine phytoplankton are
distinguished, representing a wide variety of
organisms
5Phytoplankton
Phytoplankton account for about half of global
primary production
6Types of Phytoplankton
- Bacteria and cyanobacteria
- Diatoms
- Dinoflagellates
- Others
7Photosynthetic Bacteria and Cyanobacteria
8Photosynthetic Bacteria
- Prokaryotic (Kingdom Monera)
- Contain bacterial chlorophyll (different from the
other chlorophyll molecules)
9Cyanobacteria
- Prokaryotic (Kingdom Monera)
- Contain chlorophyll-a (like eukaryotic autotrophs)
10Cyanobacteria
- Important primary producers
- Small size (1-2µm)- large SAV ratio
- Sink or rise very slowly
- Maximize nutrient absorption
- Reduces grazing loss
11Cyanobacteria
12A cyanobacteria bloom
13The Diatoms
14Diatom Cellular Structure
(chrysolaminarin)
(chlorophyll a and c, fucoxanthin, etc)
15The Diatoms
16Planktonic diatoms
- Silica shell and lack of flagella sinking
- diatoms evolved various strategies to counter
sinking - chains
- spines
- oil droplets
- ionic regulation - internal ion concentration is
lower than external seawater reduction in
density
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18Diatoms with elaborate spines and
processes Functions
19The Dinoflagellates
20Dinoflagellate Characteristics
- Typically 2 flagella
- Large nucleus (looks like a fingerprint)
- Chlorophylls a and c
- Accessory pigments (ß-carotene, peridinin,
xanthophylls) - Food reserve is starch
21Dinoflagellate Characteristics
22Dinoflagellate Characteristics
- Some are autotrophic, others are auxotrophic,
others are mixotrophic, others are heterotrophic
23Dinoflagellate Taxonomy
- Armored
- plates (numbers, shapes)
- Naked
- size and shape
- cingular position, displacement, and overhang
- sulcal placement and intrusion
- presence/shape of apical groove
24Dinoflagellate Ecology
- Dinos tend to occur in the summer and early fall
when nutrients are more depleted and seas are
calmer
25Microflagellates
- Some (e.g., coccolithophorids) are very common
26Coccolithophores
Unicell containing a haptonema between two smooth
flagella Haptonema - a coiled appendage that is
used for feeding and sensory purposes Chlorophylls
a, c1, and c2, carotenoids Chrysolaminarin
27Coccolithophores
Single regular calcareous plates
28Prokaryotic Picoplankton
Prochlrophyta Often most abundant phtoplankton in
oligotrophic, tropical waters Have traits in
common with several taxonomic groups bacteria,
cyanobacteria, green algae
29Eukaryotic Picoplankton
Typically green algae (Chlorophyta) Contain
chlorophylls a and b, carotenoids,
xanthophylls Starch is the food reserve 1, 2, 4,
or 8 flagella
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