Lecture 7 cards Flashcards
Characteristics of the intertidal zone
Time of exposure to air (elevation/slope), aspect, substrate type
Sand beaches
Temporary habitats, interstitial community
Psammon
Interstitial community, have specializations, live between sand grains. Meiobenthos (100-1,000 um)
Beach characteristics of high energy
Steep, high wave action, unstable, water table sinks, low capillarity, high permeability, high oxygen, few bacteria, low organics
Beach characteristics of low energy
Shallow, low wave action, stable, water table at surface, high capillarity, low permeability, low oxgen, many bacteria, high organics
Zostera
Eelgrass, cold
Phyllospadix
Surfgrass, cold
Thalassia
Turtlegrass, warm
Spartina
Saltmarsh plant
Salicornia
Saltmarsh plant
Mangrove
Waxy leaves, salt glands, seeds/fruit germinate while still attached to tree, roots prop and aerial, example is Rhizophora
Highest high tide
At EHWS, between supralittoral and midlittoral
Lowest low tide
At ELWS, between midlittoral and infralittoral zones
EHWS
Extreme high level spring
MHWS
Mean high water spring
MHWN
Mean high water neap
MTL
Mean tide level
MLWN
Mean low water neap
ELWS
Extreme low water spring
Factors controlling zones
Wave action, slope of rocks, sun/shade, competiton/predation
Upper level factors
Physiological stresses
Lower level factors
Biological interactions–space is at a premium, diversity can be very high
Kelps
Laminaria, postelsia, Macrocystis, nereocystis
Rockweeds
Fucus, ascophyllum, sargassum
Rhodophyceae
Red algae, chlorophylls a and d, phycobilins, no flagellae, can occupy great depths. Polysiphonia, porphyra, chondrus, gigartina
Chlorophyceae
Green algae, chlorophylls a and b, carotenes, starch, cellulose cell walls, flagellated cells. Macroalgae include Codium, Ulva, enteromorpha
Intertidal zonation from highest to lowest
Lichen, bluegreen algal/littonina, barnacle, brown algal, red algal, laminaria (kelp) zone
Verrucaria
Lichen
Important bluegreen algae
Calothrix, Enteromorpha, Porphyra, Bangia
Calothrix
Blue green algae adapted to environmental extremes with a thick mucilage sheath, prevents desiccation and rapid salinity changes, fixes nitrogen, sticks to rocks
Littorina
Very important in bluegreen algae zone. Periwinkles, feed on algae with scraping teeth, have specialized gill structure to enable them to be out of water for extended period
Orgs in the barnacle zone
Chthamalus, Balanus, Mytilus (mussels)
Orgs in brown algae zone
Fucus, Ascophyllum, Polysiphonia (red algae), Ulva (green algae), gooseneck barnacles (Pollicipes)
Important orgs in the red algae zone
Chondrus crispus, gigartina stellata, sea anemone (anthopleura), starfish, chitons
Orgs in the laminaria zone
Sea urchins, kelps, lobsters, sea anemones, other kelps (Macrocystis, Nereocystis)
Feeding patterns
Suspension, deposit, herbivore browsers, carnivores/scavengers
Suspension Feeding
Sheets of mucus, ciliary action/mucus, setae, tentacles/tube feet, choanocytes, passive
Deposit feeding
Swallowers, tentacles, surface-siphon, setose-deposit
Herbivore browsers
Scrapers, wood feeders, symbiosis/zooxanthellae (corals, Tridachna)
Carnivores and scavengers
Anthopleura, nudibranchs, snails, crabs, starfish, urchins
Katharina
Chiton, indirect mutualism. Eats macroalgae which would naturally outcompete microalgae, which are food for limpets. Therefore when Katharina is present, limpets are present.
Keystone species concept
When a high trophiic level species exerts a disproportionate influence on a community structure. Examples include Mytilus, Pisaster, Nucella
Pisaster example
Mytilus monopolizes space, Pisaster prefers to eat it. When Pisaster is removed, Mytilus extends deeper by 3 meters and diversity decreases dramatically
Bacteria in intertidal zone
High surface-volume ratio, heterotrophic advantage, new counting techniques include epifluorescence and flow cytometry. Main role in the ocean is recycling, using aerobic and anaerobic respiration, denitricitation and sulfate reduction
Riftia
Pogonophoran tube worms, live near hydrothermal vents, 1 meter long, obligate mutualistic relationship with sulfide oxidizing bacteria, have trophosome (food body that contains cells with the bacteria), specialized hemoglobin that carries both oxygen and hydrogen sulfide simultaneously
Microbial food web
Includes Microbial loop which feeds into phytoplankton
