Lecture 5 & 6 - The Rocky Shore Ecosystem

Question 1

Explain a high energy rocky shore?

Answer 1

This is a high energy shoreline, high erosive forces such as waves, tides and wind

Question 2

What is a low energy rocky shore?

Answer 2

Low energy shoreline, low erosional processes, small fetch and a sheltered shore probably with sandy beaches

Question 3

What are the zones on the rocky shore (based on tidal coverage) from top to bottom and a brief explanation

Answer 3

Supralittoral - terrestial
Littoral Fringe - wave splash (saline)
Eulittoral - tidal zone
Sublittoral - Always covered in water

Question 4

Explain the divisions of the the Eulittoral zone

Answer 4

Upper - MHWN to EHWS
Middle MLWN to MHWN
Lower ELWS to MLWN

Question 5

What are the two types of Primary producers

Answer 5

Lichens

Macroalgea (seaweeds)

Question 6

Where are the Lichens found

Answer 6

Middle to supra, areas where there is decent exposure time

Question 7

What are the three growth forms

Answer 7

Crustose
foliose
fruticose

Question 8

What are lichens (explanation of relationship too)

Answer 8

there are in fact a combination a combination of two species one algea and one fungie. They have a symbiotic relationship of which both benefits.

Question 9

Explain the ecology of Lichens

Answer 9

The algea is embedded in the fungal hyphae, fungus takes up water and nutrients for algea and the algea povides organic carbon for fungus,

Question 10

Why are Lichens important on the ecology of the rocky shore

Answer 10

They are the colonisers

Question 11

Explain the two methods of reproduction by Lichens

Answer 11

Spore - The fungus grows a spore forming body, then the spores are released and they are very resilient which make for perfect colonisation. Bacteria joins the party after

Fragmentation - not sexual reproduction but growth by expansion

Question 12

where are macroalgea found

Answer 12

Sublittoral to upperlittoral, anywhere where they are immersed at least once in the tidal cycle

Question 13

Explain the three (and one extra) components of macroaglea

Answer 13

Holdfast (anchor)
Stipe (stem)
Frond (lamina, thallus, blade)

Bladders (for flotation when high tide)

Question 14

Explain the 3 ecological adaptations of macroalgea

Answer 14

For Water loss
> Mucilaenous coast (oily coat) and channeled thallus
For Light loss (must be submerged for photosyn to occur
> Some spp. have bladders for bouyancy
> Photosynthetic pigments: Chlorophyll a + accessory pigments

Question 15

Explain the growth of macroalgeal (2 forms)

Answer 15

> Simple cell division

> Meristematic cell division at the algal apex, division of specialised cells

Question 16

Explain the reproduction of macroalgea

Answer 16

Haploid gametophytes produce gametes, combine to form a diploid zygote, grows into a diploid organism, the sporophyte. Meiosis in the spohorophyte leads to production of haploid spores which grown into a gametophyte

Question 17

What is a haploid gametophyte

Answer 17

a organism with a single set of chromosomes

Question 18

What is a diploid zygote

Answer 18

An organism with two sets of chromosomes (just like us!)

Question 19

Give the sexual reproduction story of Porphyra a red macroalgea

Answer 19

the spores germinate when they reach the shell of a mollusc, grows into a filament, the sporophyte, which releases spores into water. These spores attach to rocks and grow into a gamephyte

Question 20

Give the sexual reproduction story of Laminaria, a brown macroalgea

Answer 20

Dominant form is the sporophyte, releases flagellate spores from a sporangium, spores settle on rocks and grown into small filamentous gametophytes. Male gametophytes release microgametes, female gametophytes grow an oogonium containing a macrogamete which is fertilised by the male microgamete. This fertilised egg grows into a zygote. The sporophyte then grows out of the zygote, i.e. out of the gametophyte.

Question 21

Name the 2 main consumer spp. found on the rocky shore in latin (english names in brackets)

Answer 21

Crustacea (crabs)

Mollusca (Limpits/snails)

Question 22

What are the main form of Mollusca spp. and the three types therein

Answer 22

Mainly the gastropoda spp. (snails) the three types are:
Trochidae - Topshells
Patellidea - Limpits
Littorinidae - Winkles

Question 23

Location of Mollusca spp.

Answer 23

Sublittoral to upper littoral and sometimes into the littoral fringe, range depends on the species, either stress tolerant or competitors resistant to predation

Question 24

Describe the growth form and the five specific bits of mollusca spp.

Answer 24

these are shelled organisms to reduce dessication and soft bodies insides with a strong muscular foot to hold on to rock or algea, compontents include:
Tentacle
Syphon
Eye
Foot
Operculum (shell like structure to ‘close the door’

Question 25

What are adaptations of Mollusca spp to minimize water loss

Answer 25

Thick shell, operculum

Question 26

What are adaptations of mollusca spp. to temperature fluctuations

Answer 26

> large surface area of shells > ridges on shells > Tolerance of enzymes to high temp (dont denature) and low temp (due to their slow metabolism)

Question 27

What are the adaptations of mullusca spp.

Answer 27

> Thick shell and operculum > Camouflage > Position on the shore (hard to reach places) > Strong muscular foot of limpits (hard to prise off)

Question 28

Explain the reproduction of mollusca spp.

Answer 28

Marine molluscs on the whole are Gonochoristic (male and female, producing two types of gametes) although some are one or the other, alteration of sex occours a small male grows into a larger female. Larvae are planktonic called veliger larvae

Question 29

What are the two types of Crustacea

Answer 29

Cirripedia - barnacles non moving | Decapoda - shrimps and prawns and crabs (benthic crawlers)

Question 30

Draw a anatomy of a barnacle (cirripedia spp.)

Answer 30

``` Cant do it on here but should include the Mouth Stomach muscle Cement gland eggs testis mantle cavity intestine muscle penis feeding legs ```

Question 31

What are adaptations of cirripedia spp. to minimise water loss?

Answer 31

Cacerous plates which close over aperture during emersion (exposure, no water covering)

Question 32

What are adaptations of cirripedia spp. to temp fluxs

Answer 32

well adapted to variations in temp, enzymes can tolerate high temps, in a pale colour to minimise heat absorption

Question 33

Adaptations of cirripedia spp. to predation

Answer 33

Cement glad to facilitate fastening to rocky substratum, calcerious plates

Question 34

Explain reproduction of the cirripedia

Answer 34

The male barnicle has the largest penis in the world (based on size) female broods fertilised eggs which hatch into a cypris larvae and swim as zooplankton until settlement on a new substratum, settlement possibly caused by chemical stimuli including pheromones from other barnacles! how mad is that!

Question 35

Explain the ecology of Reptania spp (crabs)

Answer 35

Have gills, exoskeleton,

Question 36

What are the adaptations of reptania spp. to water loss

Answer 36

Not really anything, exoskeleton isnt great at preventing water loss although not really needed as aquatic lifestyle

Question 37

Adaptations to temperature variation of reptania spp.

Answer 37

Not very tolerant to temperature change, relies on stability of the water column

Question 38

Adaptations to predation of reptania spp.

Answer 38

> Carapace > exoskeleton > camouflage > location on the rocky shore

Question 39

Adaptations to predator lifestyle of reptania spp.

Answer 39

> Compound eyes (move differently) > Chemical receptors (to aid food selection) > Touch receptors (to feel movement)

Question 40

Sexual reproduction of reptania spp.

Answer 40

Gonochoristic -> Sexual reproduction Mating involves courtship and courtship sounds produced. Transfer of sperm from male to female Female in “berry form” broods fertilised eggs Eggs hatch into zoea larvae which is planktonic. Larvae develops and settles to seafloor and develops into adult crab

Question 41

what stresses increase as you move up the rocky shore

Answer 41

Temperature Salinity Desiccation Food Supply

Question 42

What stresses increase as you move down the rocky shore

Answer 42

Wave action Competition Predation