Intertidal Ecology

Question 1

what are the important abiotic factors of rocky shores?

Answer 1

full force of waves
risk of desiccation 
temperature variation 
salinity variations 
oxygen concentration variations

Question 2

animals surviving wave action

Answer 2

barnacles 
limpets 
topshells 
periwinkles 
dogwelks 
mussels 
crabs 
starfish and fish

Question 3

important rocky shore grazers

Answer 3

acorn barnacles, periwinkle and limpets

Question 4

important rocky shore detritus and macroalgae feeders

Answer 4

topshells

Question 5

important rocky shore predators

Answer 5

dogwelks, mussels, crabs, starfish and fish

Question 6

example of protoandrous hermaphrodite

Answer 6

patella vulgata
females = 2-4yrs
males > 4yrs

Question 7

organism in rocky shore pools

Answer 7

urchins 
starfish 
anemones 
encrusted algae 
coraline seaweed

Question 8

rocky shores - algae is dominant in…

Answer 8

sheltered shores

Question 9

what is the littoral zone?

Answer 9

extends from the high water mark, which is rarely inundated, to shoreline areas that are permanently submerged

Question 10

what is the eulittoral zone?

Answer 10

the habitat formed on the lower shore of an aquatic ecosystem, below the littoral zone

Question 11

Rocky shore - Lower eulittoral – sublittoral fringe contains…

Answer 11

kelp e.g. Oarweed

wrack seaweed, e.g. serrated wrack

Question 12

what is fucoid algae?

Answer 12

brown algae

Question 13

upper rocky shore brown algae

Answer 13

Spiral wrack and channel wrack

Question 14

middle rocky shore brown algae

Answer 14

bladder wrack ad knotted wrack

Question 15

sublittoral rocky shore zone algae

Answer 15

red and green algae

Question 16

adaptations to resistance to water loss on rocky shore

Answer 16

1. move to moist crack and crevaces/under algae - e.g. crabs
2. impermeable shell - e.g. limpets (patella, lottia…)
3. opercula which completely seal off aperture to shell - e.g. periwinkles
4. close shells - e.g. barnacles
5. tolerance to severe water loss - e.g. high intertidal algae
6. lives in cracks and crevices - e.g. anemones

Question 17

behavioural adaptations to maintain heat balance on rocky shores

Answer 17

go to shade

Question 18

structural adaptations to maintain heat balance on rocky shores

Answer 18

relatively large body size (comparatively) - e.g Littorina littorea
reduce body area in contact with the substrate
greater elaboration of shell ridges
colour
evaporate water off surfaces

Question 19

what are the two main mechanisms for high temperatures in heat balance?

Answer 19

reducing heat gain from the environment

increasing heat loss from the body of the animal

Question 20

adaptations to mechanical stress on rocky shores

Answer 20

become fixed to substrate - e.g. barnacles
strong but temporary attachments
thicker shells - e.g. intertidal mollusks
strong enlarged foot - e.g. various limpets
seek shelter - e.g. crabs (mobile organisms)

Question 21

adaptations to feeding on rocky shores

Answer 21

feed when tide is in

feed at night

Question 22

adaptations to salinity stress on rocky shores

Answer 22

same adaptations which prevent desiccation

Question 23

adaptations of reproduction on rocky shores

Answer 23

free-floating eggs/larvae

planktonic larvae