Transcript Plankton

Plankton
http://www.dnr.sc.gov/marine/sertc/gallery.htm
http://www.coralreeffish.com/larvae.htm
Ocean Zones
Horizontal divisions:
 Coastal (neritic) = on/over shelf (shallow)
 Oceanic = beyond continental shelf (deep)
Vertical
divisions:
 Pelagic = open
water
 Benthic =
ocean bottom
Ocean Zones
Holoplankton
Meroplankton
Plankton or Nekton?
How fast can you swim?
 Gulf Stream peak
velocity
= 5 knots = 2.5 m/sec
 Surface currents more
typically
<0.5 knot = 0.25 m/sec
(=0.56 mph)
http://oceancurrents.rsmas.miami.edu/atlantic/img_mgsva/gulf-stream-YYY.gif
Plankton or Nekton?
Swim faster than 25 cm/sec?
Yes → Nekton:
 Dolphin = 170 cm/sec (up to 40 mph!)
 Tuna = 75 cm/sec (higher burst speeds)
No → Plankton:
 Shrimp = 5 cm/sec
 Bacteria = 0.005 cm/sec
Slow, but not necessarily small
Portuguese man-of-war
float = 12 inches wide
tentacles = over 150 ft.
long (ouch!)
http://www.dnr.sc.gov/marine/sertc/gallery.htm
Net Plankton
Phytoplankton
 Cyanobacteria
 Unicellular microalgae
 Diatoms
 Dinoflagellates
 Coccolithophorids
c2004 Pearson Education, Inc., publishing as Benjamin Cummings
http://www.daviddarling.info/images/diatoms.jpg
http://www.microscopy-uk.org.uk/micropolitan/fresh/protozoa/ceratiumdic2.jpg
Zooplankton
 Divided by life history:
 Holoplankton – spend whole life
(larval and adult stages) living as
plankton
 Meroplankton – spend only
larval stage living as plankton,
then grow up to be nekton or
benthic as adults
Zooplankton - Holoplankton
 Protozoans (unicellular):
 Foraminiferans
 Radiolarians
 Ciliates
http://www.anu.edu.au/EMU/Images/radiol.jpg
http://server1.fandm.edu/Departments/Biology/People/Shimeta/research/tin2.JPG
Zooplankton - Holoplankton
 Gelatinous:
 Jellyfish (medusa)
 Siphonophores
NOAA
http://life.bio.sunysb.edu/marinebio/plankton.html
Zooplankton - Holoplankton
 Gelatinous:
 Comb jellies
(ctenophores)
Zooplankton - Holoplankton
 Gelatinous:
 Salps
 Larvaceans
(invertebrate
chordates)
NOAA
Zooplankton - Holoplankton
 Molluscs:
 Pteropods (gastropods),
with and without shell
Zooplankton - Holoplankton
 Crustaceans:
 Copepods
 Amphipods
 Ostracods
 Isopods
 Krill, shrimp
http://www.oceanexplorer.noaa.gov/gallery/livingocean/livingocean.html
Zooplankton - Holoplankton
 “Arrow worms”
(Phylum Chaetognatha)
http://pharyngula.org/images/chaetognathhead.jpg
http://www.microscopy-uk.org.uk/mag/imgjan00/CHAET2b.JPG
Zooplankton - Meroplankton
 Mollusc larvae:
 Trochophore
 Veliger
http://oceanlink.island.net/abaloneproject/growthanddevelopment/growth%20and%20development.htm
http://people.bu.edu/veliger/
Zooplankton - Meroplankton
 Crustacean larvae:
 Crab zoea
 Shrimp, barnacle
nauplius
 Lobster phyllosoma
NOAA
http://www.dnr.sc.gov/marine/sertc/gallery.htm
http://www.science-in-salamanca.tas.csiro.au/themes/larval/phyllosoma-early.htm
Zooplankton - Meroplankton
 Other larvae:
 Starfish (bipinnaria)
 Brittle stars, urchins (pluteus)
NOAA
http://raven.zoology.washington.edu/embryos/
Zooplankton - Meroplankton
 More larvae:
 Polychaete worms (trochophore)
http://www.microscopy-uk.org.uk/mag/imgmar99/poly3.jpg
Zooplankton - Meroplankton
 Fish larvae
http://www.coralreeffish.com/larvae.htm
That Sinking Feeling
 It’s a long way down – average
ocean depth around 4000 m
 Phytoplankton – need to stay in the
light surface layer (0-200 m)
 Zooplankton – eat the phytoplankton
and/or other zooplankton, so need to
be where the food is
http://www.nerc.ac.uk/images/photos/lp-ocean-sunlight.jpg
That Sinking Feeling
 Why am I sinking? Denser than water
 Densities (in g/cm3):
 Seawater = 1.025
 Air = 0.00125
 Lipids = 0.9
 Proteins = 1.3
 Carbohydrates = 1.5
 Cellulose = 1.5
 Silica shell = 2.6
 Calcareous shell = 2.8
That Sinking Feeling
 How not to sink:
 Float –
 Lipids (less dense than water)
 Gas vacuoles, sacs, bubbles
http://www-cyanosite.bio.purdue.edu/images/images.html
That Sinking Feeling
 How not to sink:
 Stay neutral
 High water content
(gelatinous)
 Reduced or no shell
NOAA
That Sinking Feeling
 How not to sink:
 Drag (high surface area) –
 Small size
 Flat shape
 Spines, long structures
-------Isopod
That Sinking Feeling
 How not to sink:
 Upwelling (also good for
nutrients)
Southern Hemisphere –
Ekman transport to the left
That Sinking Feeling
 How not to sink:
 Actively swim – cilia, flagella,
muscles, appendages
http://www.coralreeffish.com/larvae.htm
Nowhere to Hide
 Active predators can’t eat what
they can’t see – so be invisible
Nowhere to Hide
 Active predators can’t eat what they
can’t see – so hide where it is dark
Somewhere to Hide
 Floating mats of macroalgae and
seagrasses form pelagic communities
- camouflage
Sargassum
NOAA
http://www.bigelow.org/bacteria/teach/images/open_orgs/sargassum.jpg
http://www.naturalsciences.org/education/deepsea/images/sargassum_fish.jpg
Food Webs
Food Webs