1. Plankton http://www.dnr.sc.gov/marine/sertc/gallery.htm http://www.coralreeffish.com/larvae.htm

2. Vertical divisions:  Pelagic = open water  Benthic = ocean bottom Horizontal divisions:  Coastal (neritic) = on/over shelf (shallow)  Oceanic = beyond continental shelf (deep) Ocean Zones

4. 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

5. 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

6. Slow, but not necessarily small http://www.dnr.sc.gov/marine/sertc/gallery.htm Portuguese man-of-war float = 12 inches wide tentacles = over 150 ft. long (ouch!)

7. Net Plankton

8. Phytoplankton  Cyanobacteria  Unicellular microalgae  Diatoms  Dinoflagellates  Coccolithophorids http://www.daviddarling.info/images/diatoms.jpghttp://www.microscopy-uk.org.uk/micropolitan/fresh/protozoa/ceratiumdic2.jpg c2004 Pearson Education, Inc., publishing as Benjamin Cummings

9. Zooplankton  Protozoans (unicellular):  Foraminiferans  Radiolarians  Ciliates http://server1.fandm.edu/Departments/Biology/People/Shimeta/research/tin2.JPGhttp://www.anu.edu.au/EMU/Images/radiol.jpg

10. Zooplankton  Gelatinous:  Jellyfish (medusa)  Siphonophores http://life.bio.sunysb.edu/marinebio/plankton.html NOAA

11. Zooplankton  Gelatinous:  Comb jellies (ctenophores)

12. Zooplankton  Gelatinous:  Salps  Larvaceans (invertebrate chordates) NOAA

13. Zooplankton  Molluscs:  Pteropods (gastropods), with and without shell

14. Zooplankton  Crustaceans:  Copepods  Amphipods  Ostracods  Isopods  Krill, shrimp http://www.oceanexplorer.noaa.gov/gallery/livingocean/livingocean.html

15. Zooplankton  “Arrow worms” (Phylum Chaetognatha) http://pharyngula.org/images/chaetognathhead.jpghttp://www.microscopy-uk.org.uk/mag/imgjan00/CHAET2b.JPG

16. Zooplankton  Mollusc larvae:  Trochophore  Veliger http://people.bu.edu/veliger/http://oceanlink.island.net/abaloneproject/growthanddevelopment/growth%20and%20development.htm

17. Zooplankton  Crustacean larvae:  Crab zoea  Shrimp, barnacle nauplius  Lobster phyllosoma http://www.dnr.sc.gov/marine/sertc/gallery.htm http://www.science-in-salamanca.tas.csiro.au/themes/larval/phyllosoma-early.htm NOAA

18. Zooplankton  Other larvae:  Starfish (bipinnaria)  Brittle stars, urchins (pluteus) http://raven.zoology.washington.edu/embryos/ NOAA

19. Zooplankton  More larvae:  Polychaete worms (trochophore) http://www.microscopy-uk.org.uk/mag/imgmar99/poly3.jpg

20. Zooplankton  Fish larvae http://www.coralreeffish.com/larvae.htm

21. Zooplankton  Not all zooplankton are larvae  Those that are larvae, grow up to be nekton or benthic = meroplankton

22. Zooplankton  Not all zooplankton are larvae  Those that live whole lives as plankton = holoplankton http://www.oceanexplorer.noaa.gov/gallery/livingocean/livingocean.html

23. 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

24. That Sinking Feeling  Why am I sinking? Denser than water  Densities (in g/cm 3 ):  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

25. 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

26. That Sinking Feeling  How not to sink:  Stay neutral  High water content (gelatinous)  Reduced or no shell NOAA

27. That Sinking Feeling  How not to sink:  Drag (high surface area) –  Small size  Flat shape  Spines, long structures -------- Isopod

28. That Sinking Feeling  How not to sink:  Upwelling (also good for nutrients) Southern Hemisphere – Ekman transport to the left

29. That Sinking Feeling  How not to sink:  Actively swim – cilia, flagella, muscles, appendages http://www.coralreeffish.com/larvae.htm

30. Nowhere to Hide  Active predators can’t eat what they can’t see – so be invisible

31. Nowhere to Hide  Active predators can’t eat what they can’t see – so hide where it is dark

32. Somewhere to Hide  Floating mats of macroalgae and seagrasses form pelagic communities - camouflage http://www.bigelow.org/bacteria/teach/images/open_orgs/sargassum.jpghttp://www.naturalsciences.org/education/deepsea/images/sargassum_fish.jpg NOAA Sargassum

33. Food Webs