the open ocean- plankton

Question 1

define plankton

Answer 1

• Plankton: organism that lives in water column, too small to swim counter to currents

Question 2

sizes?

Answer 2

mega (>20cm); macro (2-20cm); meso (0.2-2cm);
micro (20-200µm); nano (2-20µm); pico (0.2-2µm);
femto (<0.2µm)

Question 3

7 types of plankton

Answer 3

• Mixotrophic plankton (such as protists)
meroplankton (part); holoplankton (all); neuston (surface); pleuston (protrude)
• Bacterioplankton (heterotrophic and autotrophic)
• Virioplankton (infect plankton).

Question 4

what phytoplankton contribute to 50% of photosynth

Answer 4

Protists and bacteria = 50% of the worlds photosynthesis and O2

Question 5

what do diatoms dominate as? how can they restore full size

Answer 5

• Dominate as nanoplankton (2-20um) or microplankton (20-200um)
  
  • Auxospore formation (sexual):to restore full cell size

Question 6

what can diatoms produce

Answer 6

•

Can produce domoic acid (neurotoxin

Question 7

where do dinoflagellates dominate? size?

Answer 7

• Dominate subtropical and tropical

* Nano to micro

Question 8

what characteristics do dinoflagellates exhibit

Answer 8

• Have theca (overlapping cellulose plates)
  
  • Rapid reproduction
  • Resting stages (cysts)
  • Some bioluminescent

Question 9

describe red tides

Answer 9

○ Often red blooms not toxic

Neurotoxins saxitoxi;brevetoxin

Question 10

describe • Haptophytes (coccolithophoridae; haptophyceae)

Answer 10

• Less than 20 um, 1-2 chromatophores, haptonema
○ Cocolithophores
○ unicellular nanoplankton; coccoliths (shelled) & naked forms
○ form large deposits

Question 11

describe • Silicoflagellates (crystophyceae)

Answer 11

• Unicellular;biflagellate
  
  • Silica scales
  • Dominate in antarctic

Question 12

describe green algae

Answer 12

• Rare in open water
  
  • Dominate estuaries; lagoons
  • Flagellated or non mobile

Question 13

describe Cryptomonad flagellates

Answer 13

• Widespread in estuaries

Unique chrolophyll a; c; phycobilin

Question 14

describe cyanobacteria

Answer 14

• Dominate near shore ( restricted circ)
  
  • Nitrogen fixers and photosynthesizer
  • Trivia: red sea named after Trichodemium erythraeum
  • Cyanobacterial toxins

Question 15

describe • Prochlorophytes

Answer 15

• Recently discovered
  
  • 0.6-0.8 um
  • Most abundant in the ocean
  • Contribute 1/3 to 4/5 of all productivity
  • Unique chlorophyll termed divinyl (accessory pigment)

Question 16

describe other new bacterial groups

Answer 16

• Use proterhodopsin - photoprotein
  
  • E.g. group Alpha proteobacteria do not produce O2
  • Bacterioplankton in this group amount may exceed total biomass of all phytoplankton
  • associated with POC’s and/or on zooplankton

Question 17

plankton viruses?

Answer 17

• Very little known about these
  
  • Most common infectious agents 10^10 /L in oceans
  • Regulate many bacterial/phytoplankton pops.