Phytoplankton
• What are the phytoplankton?
• How do the main groups differ?
Zooplankton
Phytoplankton
Nutrients
Plankton
“wandering” or “drifting”
(incapable of sustained,
directed horizontal
movement)
www.shellbackdon.com
Nekton
Active
swimmers
Components of the Plankton
Virioplankton:
Viruses
Bacterioplankton: Bacteria — free living planktobacteria;
epibacteria attached to larger particles
Mycoplankton:
Fungi
Phytoplankton:
Photosynthetic microalgae,
cyanobacteria, and prochlorophytes
Zooplankton:
Heterotrophic — Protozooplankton
(unicellular) and Metazooplankton (larval
and adult crustaceans, larval fish,
coelenterates…)
Components of the Plankton
Ichthyoplankton:
Planktonic fish (generally, eggs and larval stages)
Meroplankton:
Planktonic organisms that have a sedentary stage.
For example, phytoplankton with resting stages in
sediments
Holoplankton:
Wholly planktonic
Components of the Phytoplankton:
Older scheme
Netplankton:
Inspecting a small plankton
net. In: "From the Surface to
the Bottom of the Sea" by H.
Bouree, 1912, Fig. 49, p. 61.
Library Call Number 525.8
B77.
Plankton that is
retained on a net
or screen, usually
20 - 100 µm
Nanoplankton: Plankton that
passes the net, but
which is > 2 µm
Ultrananoplankton: Plankton <
2µm
Components of the Plankton
(older scheme)
Netplankton:
Plankton that is retained on a net or screen, usually
20 - 100 µm
Nanoplankton:
Plankton that passes the net, but which is > 2 µm
Ultrananoplankton:
Plankton < 2µm
Microzooplankton:
Zooplankton in the microplankton (i.e., < 200 µm)
Length Scales to Define Plankton Groups
Sieburth, J. M., Smetacek, V. and Lenz, J. (1978). Pelagic ecosystem structure: Heterotrophic compartments of the
plankton and their relationship to plankton size fractions. Limnol. Oceanogr. 23: 1256-1263.
Terminology and Scales: SI Units
FRACTION
PREFIX
SYMBOL
EXAMPLE
10-1
deci
d
decimeter, 10cm, length of a
planktivorous fish
10-2
centi
c
1 centimeter, diameter of a
ctenophore
10-3
milli
m
1 millimeter, length of a
copepod
10-6
micro
µ
1 micrometer, diameter of a
very small phytoplankter or a
large bacterium
10-9
nano
n
1 nanogram, weight of a fairly
small phytoplankter
10-12
pico
p
1 picogram, chlorophyll content
of one small phytoplankter
10-15
femto
f
1 femtogram, amount of ATP in
a phytoplankter
10-18
atto
a
att’s a small number!
Scales: The ocean is a dilute
environment!
___________________________________________________________________________________
SOME CHARACTERISTIC SCALES
(values representative of coastal waters to an order of magnitude)
organism
copepod
dinoflagellate
diatom
cyanobacterium
bacterium
virus
linear
dimension
1 mm
35 µm
10 µm
0.6 µm
0.5 µm
0.07 µm
numerical
density
5 liter-1
10 ml-1
-1
103 ml
-1
105 ml
-1
106 ml
-1
107 ml
mm3 m-3
(ppb)
2600
225
525
11
65
2
spacing
6 cm
5 mm
1 mm
200 µm
100 µm
50 µm
in body
lengths
60
150
100
350
200
650
Characterizing Constituents of the Water
Detritus:
Matter of organic origin, but incapable of
reproduction (dead)
Seston:
All suspended particulate matter
Tripton:
The non-living part of seston
DOM:
Dissolved organic matter (passes a fine filter)
CDOM:
Chromophoric (colored) DOM
Neuston:
Inhabiting the surface layer
Allochthonous:
Developed or originating from elsewhere
Autochthonous: Endemic: originated locally
Modes of Nutrition
Autotrophic:
No material of organic origin is required
for growth and reproduction
Auxotrophic:
Physiological requirement for one or
more organic compounds, but C is
obtained autotrophically
Heterotrophic:
Growth depends on organic material
Mixotrophic:
Autotrophic and heterotrophic nutrition
Photosynthetic mixotrophs can consume organic matter by
phagotrophy (engulfing particles) and
osmotrophy (uptake of dissolved organic materials)
Chlorophyll pigment is often equated with phytoplankton biomass
• Phytoplankton pigments influence ocean color
All phytoplankton were not made
equal...
• Even though phytoplankton are often
considered as light absorbers, packages of
pigment, or organic particles, they are
biologically very diverse
- Phylogenetic
- Metabolic
- Habitat/Niche Space
Light energy is collected by
photosynthetic pigments
All plants have
chlorophylls and
carotenoids
Some groups
(cyanobacteria,
cryptophytes, red
algae) have
phycobiliproteins
Pigments are used
to infer species
composition
Pigmentation
varies with growth
conditions
PHYTOPLANKTON
Procarya
Eucarya
(cyanobacteria
(i.e., Synechococcus,
Prochlorococcus),
(Cryptophyceae,
N2 fixers
(i.e., Trichodesmium))
Dinoflagellates,
Diatoms,
Coccolithophores,
Phaeocystis,
Chattonella )
The Taxonomic Groups of Phytoplankton:
An Overview
1. Bacteria (prokaryotes)
•
•
•
Eubacteria (heterotroph)
Archebacteria or Archaea (heterotroph)
Cyanobacteria (phototroph)
– "real Cyanobacteria"
• filamentous cyanobacteria, fix
nitrogen
• coccoid cyanobacteria
– Prochlorophytes (recently made a
new division)
2. Algae (eukaryotes)
• Chromophyta (possess chl a and c)
– Cryptophyceae
– Dinophyceae
– Chrysophyceae
– Prymnesiophyceae
– Bacillariophyceae (diatoms)
– Raphidophyceae
• Chlorophyta (possess chl a and b)
– Chlorophyceae
– Prasinophyceae
– Euglenophyceae
The taxonomic composition of phytoplankton does matter...
Phylogenies
are under
constant
revision
For our purposes,
the older
classifications are
still useful
http://tolweb.org/tree?group=Stramenopiles&contgroup=Eukaryotes
Page copyright © 1995 Mitchell L. Sogin and David J. Patterson
PROKARYOTES (continued):
Synechococcus
•
•
•
•
•
Discovered in 1979
very small (ca. 1 µm)
contains phycoerythrin
can fluoresce orange or red
counted with epifluorescence
microscopy or flow cytometry
http://www.woodrow.org/teachers/esi/1999/
princeton/projects/cyanopigs/data.htm
reprinted from Johnson and Sieburth 1979
PROKARYOTES (continued):
Prochlorococcus
•
•
•
•
Discovered in 1988
Very small (<1.0 µm)
Divinyl chl a
Counted by flow
cytometry
• Most abundant
autotroph on earth
reprinted from Johnson and Sieburth 1979
PROKARYOTES (continued):
Trichodesmium
(Oscillatoria thiebautii)
•
•
•
•
Forms aggregates
Fixes nitrogen
Can migrate vertically
May transport phosphate
from depth to near
surface
• New production
transports more C
www.aims.gov.au/pages/research/ trichodesmium/tricho-01.html
http://www.botan.su.se/fysiologi/Cyano/Tricho.jpg
Trichodesmium
bloom
EUKARYOTES — having a true nucleus
Chromophyta - containing chlorophyll a and c
Coscinodiscus waelesii
Phytopia CD-ROM
Bigelow Laboratory
EUKARYOTES (continued): Division Chromophyta
Class Cryptophyceae
• Motile
• Contain phycobiliproteins
• Can be recognized by size and fluorescence
(flow cytometry)
Cryptomonas
www.unex.es/botanica/ clases.htm
http://mac2031.fujimi.hosei.ac.jp/PDB/Images/Mastigophora/Cryptomonas/Cryptomonas.jpg
EUKARYOTES (continued): Division Chromophyta
Class Bacillariophyceae (Diatoms)
•
•
•
Cannot swim; Can regulate buoyancy (some
can migrate)
Require silicon; Encased in Pill-box shaped
silica frustule
Important in coastal areas and spring
blooms
http://www1.tip.nl/~t936927/art_deco.html
www.oregonbd.org/Class/Chap2.htm
Diatoms
P. Roger Sweet, Indiana University
www.coastalstudies.org/stellwagen/phyto.htm
Diatoms
pennate
pennate
Images from http://www.microscopy-uk.org.uk/mag/wimsmall/diadr.html
Silica frustule
Side View
epitheca
New
hypotheca
pennate
centric
Looking Down on the Valve
centric
EUKARYOTES (continued): Division Chromophyta
Class Pyrrophyta (Dinoflagellates)
• Motile; Can migrate vertically
• “Red tides” and shellfish poisoning
• There are autotrophic and heterotrophic species
www.jochemnet.de/fiu/phaeocystis.gif
Dinoflagellates:
Some are bioluminescent
Noctiluca
Noctiluca bloom
www.redtide.whoi.edu/hab/rtphotos/rtphotos.html
http://www.microscopy-uk.org.uk/mag/art98/nocti.html
Dinoflagellates
Naked
Noctiluca
EUKARYOTES (continued): Division Chromophyta
Class Prymnesiophyceae (Haptophyceae)
Coccolithophores
• CaCO3 skeletal plates
• pCO2 increases
• DMS production
www.oregonbd.org/Class/Chap2.htm
Emiliania huxleyi
earthguide.ucsd.edu/images/eg/img/ehuxleyi.gif
Near-real-colour SeaWiFS image of a coccolithophore bloom in the
Bering Sea, April 1998.
earthguide.ucsd.edu/demo/zalaska/08_03_1999a.html
Coccolithophores
Coccolithophores
EUKARYOTES (continued): Division Chromophyta
Class Prymnesiophyceae (Haptophyceae)
Phaeocystis
• Jelly-like colonies clog nets and cause big
problems on beaches in Europe
http://www.icbm.de/~mathmod/pages/projects/questionna
• Food-web alterations
ire/figure/phaeocystis.gif
• DMS producer
• Common in Antarctic
http://www.coastalstudies.org/stellwagen/ph
yto.htm
www.jochemnet.de/fiu/phaeocystis.gif www.bio.uva.nl/Lesbrieven/TomTahey/bovenbouwtekst3.htm
EUKARYOTES (continued): Division Chromophyta
Class Chrysophyceae
Silicolagellates, Pelagomonas, Aureococcus
• Aureococcus brown tides
http://techcenter.southampton.liu.edu/~cgobler/BrownTide.htm
EUKARYOTES (continued): Division Chromophyta
Class Raphidophyceae
Chattonella, Fibrocapsa, Heterosigma
• toxic or harmful blooms
Chattonella marina
Chattonella antiqua
www.marine.kais.kyoto-u.ac.jp
Cells of Chattonella marina
showing different forms
(ovoid, pointed-end and sausageshaped) and a temporary cyst.
www.niwa.cri.nz/pgsf/MarineBiodiversity/ima
ges/algae6.jpg
http://www.uio.no/miljoforum/natur/fj_hav/i
mg/chat_0.gif
Sampling/Counting
Sampling/Counting
Utermöhl
Settling
chambers
Sampling/Counting
Flow
cytometer
Sampling/Counting
Sampling/Counting
CHEMTAX (HPLC)
http://www-ocean.tamu.edu/~pinckney/chemtax.htm