Plankton Community

Question 1

what is used to see the depth of the ocean?

Answer 1

sonar

Question 2

what is backscatter?

Answer 2

bottom type and dense layers of zooplankton
- send sonar wave and bounces back to determine

Question 3

when is the density the highest?

Answer 3

dusk and dawn then disperses

Question 4

how do plankton disperse?

Answer 4

vertically

Question 5

what is the layer of plankton on the surface called?

Answer 5

deep scattering layer
- density of plankton migrates daily

Question 6

what is the migration of plankton called?

Answer 6

diel vertical migrations

Question 7

why does DVM occur?

Answer 7

• predatory avoidance: light makes plankton easier to see by predators and so they remain deep during the day and surface to feed at night
• metabolic advantage: temp and FOOD
  -> conserve energy by feeding in warmer water at surface at night and moving deeper at the hotter times of day
• avoid UV damage: surface waters have UV light in day which can damage tissues

Question 8

what does vertical migration cause?

Answer 8

mixes the upper layer of the ocean

Question 9

describe plankton

Answer 9

• organisms living in the water column
• too small to swim counter to typical ocean currents -> vibe with currents

Question 10

describe nekton

Answer 10

active swimmers

Question 11

what are phytoplankton food source?

Answer 11

the sun
- photosynthetic
- autotrophic

Question 12

what are zooplankton?

Answer 12

animals
- heterotrophic

Question 13

what are mixoplankton?

Answer 13

• mixotrophic
• photosynthetic but also can ingest other organisms

Question 14

how are plankton classified?

Answer 14

by how much time spent in the water column

Question 15

holoplankton

Answer 15

permanent residents

Question 16

meroplankton

Answer 16

temporary residents
- spend larval or reproductive life in plankton
- mature = sessile

Question 17

neuston

Answer 17

associated with slick
- attach to underside of surface film

Question 18

what is an example of holoplankton?

Answer 18

krill

Question 19

what is an example of meroplankton?

Answer 19

hydrozoan jellyfish

Question 20

what is an example of neuston?

Answer 20

phalaropes

Question 21

what are diatoms?

Answer 21

• phytoplankton
• major type of algae
• forms silica shell that has 2 valves (radially symmetrical)
• reproduce by binary fission - rapid doubling (asexual spores)
• consumes much of the silica in ocean surface

Question 22

what % of photosynthesis are diatoms responsible for?

Answer 22

45

Question 23

what are dinoflagellates?

Answer 23

• phytoplankton
• unicellular
• organic shell (test) cellulose and two flagella (perpendicular or transverse)
• asexual and sexual repro
• life history stages
• benthic cysts (seafloor resting)
• autotrophic
• heterotrophic
• red tides

Question 24

red tides

Answer 24

• phytoplankton that blooms in densities that turns water red
• bioluminescent
• toxic to animals
  -> Noctiluca: non-photosynthetic, heterotroph, bioluminescent, non-toxic

Question 25

green algae

Answer 25

rare in marine waters, dominate in close estuaries/lagoons

Question 26

cyanobacteria

Answer 26

abundant
nitrogen fixation

Question 27

silicoflagellates

Answer 27

• unicellular
• biflagellate
• internal skeleton of silica scales
  -> Antarctic
  -> open ocean

Question 28

coccolithophores

Answer 28

• unicellular
• nanoplankton
• covered with calcium carbonate plates -coccoliths

Question 29

what’s an example of a coccolithophore?

Answer 29

Emiliania huxleyi

Question 30

coccoliths

Answer 30

calcium plates which shed when dead and deposited on seafloor
- blooms are massive
- coccoliths form massive deposits on seafloor

Question 31

crustaceans

Answer 31

copepods
- most abundant crustaceans in zooplankton
- planktonic and benthic forms
- Calanoida
- large medial naupliar eye
- major consumers of phytoplankton or smaller zooplankton
- planktonic larvae

Question 32

what are crustaceans?

Answer 32

zooplankton

Question 33

calanoida

Answer 33

planktonic type
distinguished by a pair of antennae
5 pairs of thoracic swimming legs

Question 34

euphausiids

Answer 34

• krill
• zooplankton
• shrimp-like
• abundant in antarctic and upwelling
• main food of baleen whales in antarctic
• feed on phytoplankton and smaller zooplankton by sieving with setae

Question 35

cnidaria

Answer 35

jellyfish
- planktonic

Question 36

what is mesoglea?

Answer 36

jelly in the middle for support (ECM), buoyancy and swimming

Question 37

cnidocytes

Answer 37

tentacles with stinging organelles
- fires when hair cilium is triggered, releasing a sticking, piercing or poison dart into prey
- some very toxic

Question 38

what do cnidaria feed on?

Answer 38

crustaceans -> hydrozoa (velum to jet swim) and scyphozoa (drifters)

Question 39

ctenophores

Answer 39

comb jellies
swim with cilia organized into 8 rows of ciliary plates called Ctenes
- colloblast - unique sticky organelles fired to trap crustacean prey

Question 40

salps, pyrosomes and larvaceans

Answer 40

urochordates
- adult filter feeding but larvae have notochord

Question 41

salps

Answer 41

tube/barrel shapred
gelatinous case
filter water through tube

Question 42

pyrosomes

Answer 42

colonies of filter feeding tunicates form vast tubes that glide

Question 43

larvaceans

Answer 43

tiny tadpole-like filter feeders
tail to generate feeding current
build massive mucous houses to feed

Question 44

chaetognaths

Answer 44

arrow worms
fast
muscular bodies- rapid swimmers
huge setae-teeth: carnivorous
major component of plankton (v. common)

Question 45

pteropods

Answer 45

• sea butterflies
• holoplanktonic snails (molluscs)
• swim by wings that project out from reduced foot
• suspension feed or carnivorous depending on species
• calcified shell
• shells are thing and at risk from Ocean Acidification (break down calcium carbonate in shell)

Question 46

unicellular eukaryotes

Answer 46

foraminifera -chambers for cytoplasm to move through
radiolaria - radially symmetrical
ciliates - everywhere