Week 6: Invertebrates 2

Question 1

How many marine animal phyla are there

Answer 1

33

Question 2

90% of marine species are

Answer 2

Marine invertebrates

Question 3

How many marine animal phyla are dominated by crustaceans and molluscs

Answer 3

11

Question 4

There are more _____ species but more _____ phyla

Answer 4

Terrestrial species, marine phyla

Question 5

Ocean contains what portion of worlds species

Answer 5

15-25% (2,200,000 species)

Question 5

Percent of earths surface as ocean

Answer 5

70%

Question 6

Life in the ocean has been how much longer than on land

Answer 6

9 times longer

Question 7

Why low marine diversity

Answer 7

1. Differences in primary production - lower in the oceans
2. A higher per area net primary productivity on land
3. A higher productivity can support more complex and diverse ecosystems
4. Lower 3-d habitat complexity in the ocean and hence less niche diversity
5. Smaller and short-lived primary producers in the ocean
6. Minimal complex plant habitats in the ocean
7. Populations well connected, so less chance of isolation
8. Marine species have larger geographic range
9. Few barriers for reproduction
10. More habitat complexity on land and hence greater niche diversity

Question 8

Low marine diversity in fish shown by total fish species between fresh and saltwater

Answer 8

17,000 species in salt
15,000 species in fresh

Question 9

Global patterns in marine biodiversity

Answer 9

1. Highest diversities in the western regions and at low latitudes for coastal species
2. Oceanic taxa had highest diversities at 30-60 degrees north and south
3. Diversities higher near the coast and along boundaries current

Question 10

Drivers of longitudinal patterns in biodiversity

Answer 10

1. Western regions have a more complex structure
2. Energy input, cold water upwelling in east
3. Prevailing westward flow of equatorial currents

Question 11

Species accumulate which way due to equatorial currents and prevailing winds

Answer 11

East to west

Question 12

Vertebrate species peak at what latitude

Answer 12

Equatorial

Question 13

Invertebrate species peak at which latitude

Answer 13

Higher latitude

Question 14

Reasons for vertebrate and invertebrate different latitudinal patterns

Answer 14

1. Fish more abundant at equator
2. Fish so dominant in equator that they outcompete invertebrates
3. Benthic invertebrate have an advantage at colder temperatures

Question 15

Species richness peaks at the equator are being more spread out due to

Answer 15

Climate change

Question 16

Key biological processes in the ocean

Answer 16

1. Feeding (suspension/detritus feeding)
2. Reproductive strategies
3. Movement
4. Gas exchange
5. Soft bodies and body composition
6. Excretion

Question 17

Food for marine invertebrates

Answer 17

1. DOM
2. POM
3. Plankton (pelagic)
4. Nekton (pelagic)
5. Pelagic detritus
6. Benthic food (deposits and detritus plants, animals)

Question 18

Feeders who concentrate and remove particles suspended in the water column

Answer 18

Suspension feeders

Question 19

Suspension feeders consume particles which can include

Answer 19

Phytoplankton, zooplankton, bacteria and detritus

Question 20

Suspension feeders feed by

Answer 20

Trapping or filtering water

Question 21

Feeders who obtain nutrients from sediment in soft bottom habitats

Answer 21

Deposit feeders

Question 22

Two types of deposit feeders

Answer 22

1. Direct deposit feeders, which swallow large quantities of sediment directly (lugworms)
2. Selective deposit feeders, which use tentacles to consume the sediment (sea cucumber)

Question 23

Specialised selective deposit feeding structures

Answer 23

Lobes, tentacles, proboscis

Question 24

Viscosity

Answer 24

A measure of a fluid's resistance to flow

Question 25

How does viscosity affect animals

Answer 25

1. Allows many animals to live suspended off the sea floor 2. Allows small animals to generate movement 3. Reduces movement in small zooplankton to darting movements

Question 26

How do macro invertebrates deal with viscosity

Answer 26

By being slow moving or sedentary with streamlining

Question 27

Overcoming high viscosity requires

Answer 27

1. Expending energy 2. Asymmetric feeding patterns and small scale eddies 3. Increasing Reynolds numbers at the filler structure by speed

Question 28

Feeding on small particles is a

Answer 28

low Reynolds number process

Question 29

The main excretory product for all aquatic invertebrates

Answer 29

Ammonia, as water provides a convenient medium for its rapid dilution

Question 30

Excreting ammonia requires

Answer 30

no energy but lots of water

Question 31

Because ammonia is highly soluble

Answer 31

It readily diffuses through fluids and tissues and is lost across the body wall

Question 32

Creatures that excrete through body wall of skin/gut lining

Answer 32

Filter feeders, such as sponges and cnidarians