GREEN ALGAE
RED ALGAE
BIOLOGICAL INTERACTIONS
OPEN OCEAN ALGAE
INTERTIDAL ALGAE
SUBTIDAL ALGAE
BIO AND PHYLO
INVASIVE SPECIES
100
What are the flagella features of green algae? (4)
1. 2 (typical), 2, 8, or more both whiplash
2. Mostly forwardly directed, some lateral
3.Some with fine hairs (not mastigonemes) and some with scales
4. Flagella on mobile spores and gametes
100
1) What are the main morphologies present in this group?
2) What are the growth forms present in this group?
1. Unicells, filaments, pseudoparenchyma, parenchyma
2.
Uniaxial organization
Multiaxial organization
Complete growth
Apical meristem - but elongation of the cells (at the base) **Rapid wound repair
100
What are abiotic factors that impact algae?
Tidal cycle, waves, currents, and light (quantity/irradiance, quality or spectral distribution, periodicity), pH, temperature, depth, turbidity, substrate, nutrients.
100
Why is the thermocline important for algae?
It is typically a location where there is high productivity. It is where there is enough nutrients, light, and temperature for reproduction.
100
What are the biological interactions that influence the zonation in Fucales within the rocky intertidal?
Competition for light from other seaweed species and grazing (Littorina snails eat young Pelvetia and Fucus but avoid Ascophyllum)
100
What are the patterns of distribution (in terms of depth) for browns, greens, and reds?
Browns tend to have a higher light requirement than greens and reds (restricted to surface depths). Reds have the broadest distribution between depths (coralline can be found very deep!).
100
What is the difference between biogeography and phylogeography.
Biogeography = the study of geographical distribution patterns of organisms and the mechanisms that produce the patterns
Phylogeography = the study of the principles and processes governing the geographic distributions of genealogical lineages. Using phylogenies to figure out how lcose things are.
100
What is an invasive species?
An invasive species is a type of introduced species (conventionally thought to be non-native) that ends up being harmful because it takes over an ecosystem at a fast rate; and kicks out other species from their niches.
200
What are the photosynthetic pigments seen in this group and what are the variety of chloroplast shapes?
Pigments:
chlorophyll a and b, siphonoxanthin (in many Ulvophyceae), carotenoids for photoprotection
Chloroplast variety:
cup shaped parietal, napkin ring parietal, star shaped, axial plate like, ribbon like, reticulate (netlike), multiple discoid.
200
What was the role of the porphyra life history in the Nori Industry? Who found it and what stage was important/how was it found?
It was important to helping them cultivate porphyra rather than finding it in the wild. Kathleen Drew Baker completed the life history by finding the Conchocelis phase (sporophyte) as it burrows into shells (boring algae). She closed the Nori life cycle. They use the shells for calcium carbonate then have gametophyte grow on string and they put it in the field. We eat the gametophyte. This was a science breakthrough needed for successful new industry.
200
What are the forces seaweed experience and what adaptations do they have to help?
1. Elasticity in tension (stretchiness)
2. Elasticity in bending...articulated corallines (flexibility)
3. Torsion (twisting)
4. Breaking strain (strength)
200
What are the major algal taxa present in the open ocean?
- Diatoms = frustules of silica, heavy, no flagella, blooms, requires light
-Haptophytes = coccoliths of CaCO3, important food source (omega 3), sequester CO2 could rerelease
-Cyanobacteria = gas vesicles, slime sheath, small
- Dinoflagellates = armored theca, cyst stage, blooms, flagella, peridinin, oil storage, trichocysts, mucocysts, nematocysts, eyespot, bioluminescence
200
Draw a diagram showing the abiotic and biotic factors that influence vertical zonation patterns of algae in the rocky intertidal.
Be able to explain this
200
1) What are the biological interactions that affect zonation patterns in the subtidal?
2) What is the general trend with grazers and depth?
1) Competition for space and herbivory
2) As depth increases, there are less grazers.
200
What are the different types of distribution patterns?
Endemic = one spot, nowhere else
Cosmopolitan = worldly
Disjunct = not continuous
Pantropical = al over tropics
Circumpolar = all over the poles
200
What are the major known vectors for invasive species?
Hull fouling, shellfish farming (algae can bore into shells, hard to see and manage), aquaculture, ballast water, Suez Canal, aquarium trade, and research
300
What are the different morphologies seen in this group?
1. Unicells: flagellated or non flagellated
2. Colonies
3. Filaments: unbranched, branched, heterotrichous:having a prostrate and upright position)
4. Parenchymatous - tissues (cells divide in 3 planes to produce flattened blades or tubes)
5. Siphonous coenocytes
300
What are the components of the cell wall structure and what are the commercial applications of the components?
It is the extracellular matrix (ECM) which is a loose network of cellulose microfibrils. It is a gel like mix of sulfated galatan polymers and mucialge (more abundant). The composition depends on agar, carageenan and calcium carbonate. Agar is used as a culture growth medium in lab petri dishes (think diatom culture experiment). Carrageenan is used to thicken foods and stabilize dairy products (think ethnobotany lab). Calcium carbonate may be used in building materials and manufacturing of products like paint, paper, and textiles
300
What are the roles of algae in food webs?
1. Foundation of the food web
2. Eaten by small grazers and large macrograzers
3. Mutualistic associations with herbivores (get ammonia from waste
4. Epiphytes
Benefit of them = herbivores may eat them rather than the main organism
BUT... lots of significance statistically that they cause more drag.
300
What are the adaptations that allow non-motile algae to remain suspended in the water column?
Small size, being a shape other than spherical, and spines or other projections from the cell
300
1) What forces are the seaweed dealing with in more exposed coastlines?
2) What adaptations do seaweed have to cope with these forces?
1) Compression forces, shear stress, drag forces
2) Elasticity, bendability, tension, torsion, more sturdy attachment point, alginate composition with facilitative M/G ratio
300
What are the different ways algae compete for space?
- Allelopathy = chemical inhibition of one plant by another due to release into environment of substances acting as germination or growth inhibitors.
- Overgrowth = of some algae on "host" not extracting nutrients from "host" they are just using it for space "host" map keep epiphyte to avoid herbivory.
- Overtopping = shading lower algae underneath
-herbivory = pressure sets the limits of depth but within light requirement.
300
What is the difference between dispersal and viccariance?
Dispersal: species movement away from
parent population
Vicariance: geographic range of a taxon is split
by formation of a physical barrier. In the ocean, physical barriers are things like land bridges
300
What are the characteristics of an invasive species?
No predation/herbivory
Broad tolerance -> physiological plasticity, resilient
Strong competitors
Rapid growth/reproduction
Difficult to manage
High dispersal capacity
Associated with humans
400
Describe the reasoning on why Enteremorpha and Ulva are not different groups. How did linnaeus determine this and what are the results?
Enteremorpha was the old name for the Ulva tube morphology, but now all are called Ulva. They are not distinct genera and linnaeus was right in saying this. When they tested enteremorpha and Ulva, they were not actually different enough to be separate. In the phylogeny shown, Enteremorpha and Ulva were placed as sister groups in multiple places signifying that they were too close to be different.
400
What are the different types of parasites in red algae and how are they a useful model system for understanding parasitism in other groups?
1. Adelphoparasite: parasite grows on a closely related host
2. Alloparasite: parasite on a host not sharing a common ancestor
3. Promiscuous alloparasite: parasite grows on several hosts, at least one of which is not closely related
Researchers can compare the genetic and morphological changes between the parasite and a closely related free-living organism. This helps understand the development/evolution into a parasite since many have a close relationship with their host.
400
1) What is the competitive exclusion principle?
2) What resources do algae compete for?
1) Two species cannot coexist on the same limiting resource
2) Light, food, nutrients, water, and space
400
Describe the distribution patterns of major open ocean algae.
The concentration of chlorophyll a (mg/m3) is a good proxy. The highest chlorophyll concentrations, where tiny surface-dwelling ocean algae are thriving, are in cold polar waters or in places where ocean currents bring cold water to the surface, such as around the equator and along the shores of continents and small land masses.
400
Analyze how seaweeds modify habitat in the intertidal
The provide structure, shelter, nutrients, limit erosion, but also can lower temp, light amounts, and water loss.
Seaweed canopies can affect algae under them by limiting light, but then they increase the numbers of invertebrates by providing them with structure, protection, and helping with water loss. This can help prevent dessication in them.
400
How do kelps modify their habitat in the subtidal?
Macrocystis pyrifera (giant kelp) is an indirect facilitator. It has been shown to have positive effects on sessile invertebrates and negative effects on understory algae. The biggest impact of kelp is from its frond density (not holdfast cover). Giant kelp limit light availability with their fronds.
The reduction of light likely has the greatest impact on benthic community structure. Giant kelp has also been found to reduce current speeds, which can increase sedimentation rates and further reduce light. They also can affect bottom space availability with their holdfasts (but it's not as severe as the impact of the fronds).
400
What are the major factors driving biogeographic patterns?
Plate tectonics, glaciation, wind, temperature (there is a min and max for survival)
400
What are the two hypotheses as to why invasive species are successful?
Enemy Release Hypothesis (ERH): an invader is more successful in its introduced range because it has escaped its natural enemies and herbivores present in its native habitat
Resource-Enemy Release Hypothesis (R-ERH): an invader first benefits from escape from natural enemies and then from greater resource availability in the invaded area
500
What features do early land plants and primitive land plants have?
Heterotrichous organization (prostrate and uprights)
Sophisticated egg protection
Swimming male gametes
500
What role did the lack of flagella play in the evolution of the major life history type in this group?
Red algae have NO flagella at any life stage, meaning they have no motile gametes.
They have small genomes and it suggests that movement was not needed (no sexual reproduction or no sperm competition), swimming was not possible or was expensive. Likely means that ancestral red algae lived in an environment that was unfavorable for flagella like an extreme environment. So...the triphasic life history evolved because it was a way to compensate for nonmotile gametes and believed rare occurrence of syngamy in the ancestral algae.
This life cycle provides retention, nurture, and replication of the zygote by the gametophyte to form the carposporophyte. Multiple diploid spores are released into the environment to produce multicellular diploid plants, many cells of which divide meiotically when forming spores to give a potentially great diversity of genotypes from a single original zygote.
500
How does light affect algae?
-Quantity or irradiance = photon flux density (amount of photons that pass through) Can predict these at depth using the Beer-lambert law.
the amount of light changes with depth, latitude, tidal exposure, cloud cover, shore shading, biological canopy, and wave action.
- Quality or special distribution
varies with depth, transparency, tidal amplitude, phytoplankton density and diversity, turbidity, silt.
Quality refers to wavelength (different organisms can use different wavelengths depending on pigments)
EX: open ocean has lowest extinction coefficient because of clear water whereas temperate coastal waters have a higher extinction coefficient
500
How has climate change impacted algal communities in the Bering Sea?
Bering Sea ice has retreated from 1970 to 2002, causing a shift in algal composition. Climate change has caused the ice to melt more quickly leading to shifts in algal composition from diatoms and phytoplankton to pelagic algae like Haptophytes. This changes the trophic cascade since there are different algae available, different fish will come and eat them causing a different environment. If there is not a diatom/phytoplankton bloom or if its late, the fish will have less food and may result to eating their young. This is called the oscillating control hypothesis. The diatoms can sink or bloom late due to loss of stratification in the water column leading them to be out of the photic zone. (no stratification due to winter storms). If ice melts too early, water wont be warm enough to form thermocline therefore bloom is pushed back to when water warms. IF thermocline doesnt from they could sink and results in no ice algae and instead pelagic algae will change to be the main algal composition.
500
What is the zonation like in the rocky intertidal and what factors affect this zone?
Abiotic factors drive the upper zone while biotic factors drive the zonation at the low.
Abiotic = wave action, tides, dessication, current, light
Biotic = competition and herbivory
EXPERIMENT = hall all 3 species in the same area and see how and where they populate. Chondrus crispus will out compete Ulva and fucus for the low zone.
500
Evaluate the distribution and ecological data to understand where kelps are found on a global scale.
DEEP WATER REFUGIA
This heped Kelps distribute from North to South through the ban of the tropics. The deep water refugia was the cold water channels they could take under the warmer waters. They stopped along that path when conditions were good in the tropics where the light requirement is below the thermocline. So these colder kelp species could inhabit the area
500
What are the factors and processes that influence a species phylogeography?
Species likely originated where there are more. Haptophytes see meaning there is more genetic diversity. If it is a monophyletic group like Macrocystis seen in the South, then there was one diversification event. Phylo looks at one species.
500
1) How was invasive Caulerpa taxifolia introduced?
2) Why was this invasive strain such a good invader?
3) How did they eradicate this invasive species in California?
1) Invasive Caulerpa was introduced from the aquarium trade as it is a common aquarium plant in Europe and North America. A coldwater strain (probably originating from Australia) was released into the Mediterranean Sea near the Oceanographic Museum of Monaco.
2) Aquarium strain is a great invader because…
Grows quickly on a variety of substrates
Can tolerate variable temperatures and salinity
Can live at a variety of depths (1m to 12m)
Reproduction by fragmentation (a fragment can be as small as 1 cm)
Lacks predators, produces a toxin (caulerpenyne) that discourages grazing
3) To get rid of Caulerpa, they injected chlorine under a tarped area, which killed everything present (e.g., organisms in the benthos) including the Caulerpa. This took 6 years and cost $7 million.