Bio 346 - Freshwater Eco. (Chpt 23) --> Zooplankton

Question 1

Typically what are the macrozooplanktons that are larger than 200um?

Answer 1

Crustaceans

Question 2

Typically what are the microzooplanktons that are smaller than 200um?

Answer 2

Rotifers

Question 3

Zooplankton

Answer 3

Any plankton thats an animal

Question 4

What was used in the 20th century to sample zooplankton?

Answer 4

Nets made out of silk bolting cloth (60-70um) that would catch both crustaceans and rotifers

Question 5

Negative effects to the net cloths for sampling?

Answer 5

It provides resistance to flow of water through them and allow water to flow from the mouth resulting in an underestimation of the biomass of organisms

Question 6

What has been introduced in order to fix the negative effects of the net cloths for sampling?

Answer 6

Traps –> Schindler Patalas Traps

Question 7

Schindler Patalas Traps

Answer 7

• 2 hinged door swings upward and the trap is lowered and closed at the desired depth when the hauling up commences
• Water then flows out and all is caught in the traps
• Provides little warning to the light sensitive zooplankton (best to collect at night)

Question 8

What is the best way to collect samples of protozoans?

Answer 8

bottles or pumps rather than nets

Question 9

What are 8 ways the heterogeneous distribution of the lake zooplankton occurs?

Answer 9

1. System morphometry (lake depth and shape)
2. The configuration of inflows and outflows
3. Prevailing winds
4. Current patterns
5. Upwellings
6. Competition for food resources between zooplankton species
7. Predators
8. Vertical migrations in deeper lakes and horizontal or transversal migrations in shallow lakes

Question 10

What are determinants for accurate production that link abundance patterns to environmental factors in all organisms?

Answer 10

Good and frequent abundance of species

Question 11

Keystone species

Answer 11

A species now which other species in an ecosystem largely depend on, such that if it were to be removed the ecosystem would change drastically
Eg) Daphina (Water Fleas)

Question 12

What are the most important soft bodied multicellular invertebrates in the plankton family?

Answer 12

Rotifers

Question 13

What are 2 important aspects of rotifers?

Answer 13

1. Important food source

2. Contributes to the decomposition of soil organic matter

Question 14

Multivoltine

Answer 14

Invertebrates producing more then one generation per year

Question 15

Bivoltine

Answer 15

Those completing 2 life cycles per year

Question 16

Univoltine

Answer 16

Those that produce one generation per year

Question 17

Semivoltine

Answer 17

Species requiring 2 years to complete a life cycle

Question 18

Merovoltine

Answer 18

Those with a longer life cycle

Question 19

What life cycle do rotifers have?

Answer 19

Multivoltine

- because they produce unfertilized but diploid 2N) eggs

Question 20

What happens to the reproduction rate as temperature increases?

Answer 20

Increases

- Larger organisms need higher temps to reproduce compared to smaller organisms

Question 21

Cladocerans

Answer 21

• Type of crustacean
• Normally covered by a hard chitinous cover
• Respiration occurs though gills or through body surface
• 2 large antennae give them the name “water flea” and uses them for rowing through the water
• Produce many offsprings
• Regulated by egg production

Question 22

Copepods

Answer 22

• Type of crustacean
• Regulated by longevity and survival rate
• Dependent on sexual reproduction
• Development time is determined by water temperature

Question 23

What are 3 examples of copepods?

Answer 23

1. Cyclopoid copepods
   - Generally predatory (carnivore)
2. Calanoid copepods
   - Omnivore
3. Harpecticoid copepods
   - Primarily benthic

Question 24

Ostracods

Answer 24

• Type of crustacean
• Benthic
• Frequently vert common in sediments and on macrophytes
• Bodies are flattened from side to side and protected by a bivalve-like shell (chitinous)

Question 25

Malacostracans

Answer 25

- Larger crustaceans - eg) crabs, lobsters, catfish, shrimp, krill.... - Segmented bodies (head, thorax and abdomen)

Question 26

What is the principle predictor of crustaceans and rotifer specie abundance?

Answer 26

Lake area

Question 27

What type of lake are invertebrate species abundance greatly reduced?

Answer 27

Saline lakes

Question 28

Habitat diversity hypothesis

Answer 28

Theory that explains the relationship between species abundance and the surface area of oceanic islands

Question 29

What is the 2nd predictor of crustaceans and rotifer specie abundance?

Answer 29

Annual phytoplankton primary production

Question 30

Whats happens to species abundance as area increases

Answer 30

Increases

Question 31

What are season cycles affected by? (3 things)

Answer 31

1. Size distribution and their algal and bacterial prey 2. Disease and selective predation by fish 3. Invertebrate predators

Question 32

What happens with huge variability in temperate zones? | 2 things

Answer 32

1. Leads to increase in zooplankton and nanoplankton | 2. Decrease in temp decreases abundance in zooplankton

Question 33

What happens to the pronounced seasonality at mid/high latitudes when shifted to lower latitudes?

Answer 33

Becomes more muted

Question 34

What 6 things affect water column stability?

Answer 34

1. Mixed-layer light climate 2. External and internal nutrient loading 3. Primary production 4. Fish reproduction 5. Zooplankton 6. Population dynamics

Question 35

What are 4 patterns shown at lower latitudes?

Answer 35

1. More modest seasonal changes in irradiance and temp 2. Greater seasonal variability in rainfall 3. River discharge 4. Wind speed

Question 36

What is the best way long-term patterns are recorded?

Answer 36

In sediments

Question 37

What are 4 factors that cause large inter-annual and decade-long variation?

Answer 37

1. Changes in predation pressures from fish or invertebrates 2. Changes in zooplankton food supply related to nutrient supply and algal density 3. Changes in spring -- ice covered and algal growth in spring 4. Competitive interactions among zooplankton species

Question 38

What kind of relationship is between fish density and Daphina? (+ or -)

Answer 38

Negative relationship

Question 39

What dramatic effects can manipulation of planktivorous fish stocks have? (3 things)

Answer 39

1. Zooplankton abondance 2. Biomass 3. Community structure

Question 40

What are 3 ways of removing zooplankton resulted from under ice anoxia?

Answer 40

1. Netting 2. Poisoning 3. Naturally by winter kills

Question 41

What does a high abundance of zooplankton do to abundances of large zooplankton ?

Answer 41

Reduces it | - Which they preferentially feed on

Question 42

What does size distribution of macro-zoo-plankton in lakes provide?

Answer 42

A useful index of the structure of fish communities

Question 43

What is water management most concerned with in the temperate zone?

Answer 43

The end result | - And not with the importance of the different mechanisms that determined the desired transparency

Question 44

What are the first steps towards the development of models that better predict impacts on aquatic systems?

Answer 44

Identification and quantification of mechanisms

Question 45

What type of macrozooplankton commonly plays a key role in reducing the phytoplankton biomass?

Answer 45

Filter feeding macrozooplanktons

Question 46

What has biomanipulation of temperate lakes been proposed to do?

Answer 46

Acts as a management tool for increase in water clarity in eutrophic systems in which a sediment reduction in internal or external nutrient loading cannot be brought about

Question 47

What 2 things does growth of a zooplankton population or community require?

Answer 47

1. Enough food of sufficient quality | 2. Appropriate size

Question 48

What happens to organismal size when the filtering rate per unit biomass decreases over a wide body-sized range?

Answer 48

It increases

Question 49

What 2 things does filtering and grazing rates depend on?

Answer 49

1. Food concentration | 2. Food quality

Question 50

Haney In-Situ Grazing Chamber

Answer 50

- Was developed to gently trap zooplankton while automatically exposing the enclosed assemblage to trace amounts of radio-labelled food particles - Uses radio-labelled cells food particles to attract zooplankton - Once caught gets filtered out and measured

Question 51

What happens to biomass as grazing rates decline?

Answer 51

Gradually declines and evens out (see graph in notes)

Question 52

What happens to biomass as TP increases?

Answer 52

Increases

Question 53

What is the most important correlation of production?

Answer 53

Population biomass

Question 54

What happens to biomass as the weight of an individual increases?

Answer 54

Decreases

Question 55

What 3 things increase with increase in temp?

Answer 55

1. Egg development 2. Growth rates 3. Feeding rates

Question 56

What 3 things do interaction between top down and bottom up define?

Answer 56

1. Community structure 2. Biomass 3. Productivity

Question 57

Cyclomorphosis

Answer 57

The pronounced died vertical migration (DVM) of macro-zoo-plankton and distinct seasonal changes in the morphology of successive generations

Question 58

What do more fish present?

Answer 58

Stronger vertical migration

Question 59

What does food dictate?

Answer 59

Where the zooplankton are in the water column

Question 60

What are the 2 environmental cues that trigger migration?

Answer 60

1. Light intensity | 2. Release if info-chemicals by a variety of predators

Question 61

What do chemical cues and alarm substances do?

Answer 61

Stimulate migration

Question 62

Kairomones

Answer 62

Chemical cues provided by the excretory products of predators

Question 63

Alarm substances

Answer 63

Cues provided by injury or partially eaten prey organisms of the same species

Question 64

What does DHM stand for?

Answer 64

Diel Horizontal Migration

Question 65

What is an important reason for migration?

Answer 65

Predator avoidance

Question 66

What does full moon light reduce?

Answer 66

The extent of migration | - Extent of migration is a function of organismal size